United States v. Reyes-Valdivia

United States Court of Appeals For the First Circuit No. 16-2089 UNITED STATES OF AMERICA, Appellee, v. JEFFRI DÁVILA-REYES, Defendant, Appellant. No. 16-2143 UNITED STATES OF AMERICA, Appellee, v. JOSÉ D. REYES-VALDIVIA, Defendant, Appellant. APPEALS FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF PUERTO RICO [Hon. Francisco A. Besosa, U.S. District Judge] Before Barron, Chief Judge, Lynch, Lipez, Howard, Thompson, Kayatta, Gelpí, Montecalvo, Circuit Judges. Raymond L. Sánchez-Maceira, for appellant Jeffri Dávila- Reyes. Franco L. Pérez-Redondo, Assistant Federal Public Defender, with whom Eric Alexander Vos, Federal Public Defender, Vivianne M. Marrero-Torres, Assistant Federal Public Defender, and Kevin E. Lerman, Research & Writing Attorney, were on brief, for appellant José Reyes-Valdivia. John M. Pellettieri, with whom Kenneth A. Polite, Jr., Assistant Attorney General, Lisa H. Miller, Deputy Assistant Attorney General, W. Stephen Muldrow, United States Attorney, Mariana E. Bauzá-Almonte, Chief, Appellate Division, and David C. Bornstein, Assistant United States Attorney, were on brief, for appellee. October 5, 2023 Opinion En Banc BARRON, Chief Judge. In these consolidated appeals, Jeffri Dávila-Reyes and José Reyes-Valdivia challenge their 2016 convictions for violating the Maritime Drug Law Enforcement Act, 46 U.S.C. §§ 70501 et seq. ("MDLEA"), despite their having pleaded guilty unconditionally to the underlying charges. The charges were set forth in a single indictment that was handed up in the District of Puerto Rico in 2015. The indictment alleged that the defendants, each of whom is a national of Costa Rica, had violated the MDLEA by trafficking drugs "on the high seas . . . and within the jurisdiction of this court" while on board a "covered vessel," 46 U.S.C. § 70503(a), which includes any "vessel subject to the jurisdiction of the United States," 46 U.S.C. § 70503(e)(1). The indictment alleged that the vessel was "subject to the jurisdiction of the United States" because it was "without nationality." 46 U.S.C. § 70502(c)(1)(A). A panel of this Court vacated the defendants' convictions and ordered the underlying charges dismissed. The panel did so based on the defendants' contention that Congress had no power under the Felonies Clause of the U.S. Constitution to criminalize their charged conduct because they were foreign nationals who were aboard a foreign vessel on the high seas at the time of that conduct. See U.S. Const. art. I, § 8, cl. 10 (granting Congress the power "[t]o define and punish Piracies and Felonies committed on the high Seas, and Offences against the Law of - 3 - Nations"). The defendants based their contention that the vessel was foreign on the ground that even if the vessel was "without nationality," 46 U.S.C. § 70502(c)(1)(A), for purposes of the MDLEA it was not stateless for purposes of international law. See United States v. Dávila-Reyes, 23 F.4th 153, 195 (1st Cir. 2022). The government petitioned for rehearing en banc. We granted the petition and vacated the panel's ruling. We now affirm the defendants' convictions, albeit on narrow, record-based grounds that bypass many of the broader questions of international and federal constitutional law that the defendants ask us to resolve. Because those questions touch on sensitive issues of U.S. foreign relations and national power that have implications far beyond this specific statutory context, it is prudent for us to resolve them only in a case that, unlike this one, requires that we do so. We do address, however, a threshold legal question about the MDLEA that itself has broad significance: Does 46 U.S.C. § 70503(e)(1), which establishes that a "vessel subject to the jurisdiction of the United States" is a "covered vessel," limit the subject matter jurisdiction of federal courts under Article III of the Constitution? See U.S. Const. art. III, § 2, cl. 1. We conclude, in accord with an earlier ruling of this Court, see United States v. González, 311 F.3d 440 (1st Cir. 2002), that - 4 - § 70503(e)(1) does not set such a limit and that the provision instead merely limits the substantive reach of the MDLEA. I. A. The MDLEA applies to drug trafficking on the high seas only if that conduct occurs aboard a "covered vessel." 46 U.S.C. § 70503(a). Section 70503(e)(1) provides that a "covered vessel" includes a "vessel subject to the jurisdiction of the United States." A U.S. vessel is a "covered vessel." See 46 U.S.C. § 70503(e)(1). But § 70502(c)(1) provides in subsection (A) that a vessel is also "subject to the jurisdiction of the United States" if it is "without nationality." Section 70502(d)(1) then states that: the term "vessel without nationality" includes: (A) a vessel aboard which the master or individual in charge makes a claim of registry that is denied by the nation whose registry is claimed; (B) a vessel aboard which the master or individual in charge fails, on request of an officer of the United States authorized to enforce applicable provisions of United States law, to make a claim of nationality or registry for that vessel; (C) a vessel aboard which the master or individual in charge makes a claim of registry and for which the claimed nation of registry does not affirmatively and unequivocally - 5 - assert that the vessel is of its nationality[.]1 B. A criminal complaint from the District of Puerto Rico was issued against the defendants on November 9, 2015. It stated that the defendants were "in violation of Title 46, United States Code, Section 70503(a)(1), 70504(b)(1), and 70506(a) and (b)."2 An affidavit from a law enforcement officer attached to the complaint recounted the following facts. On or about October 29, 2015, a maritime patrol aircraft's crew identified a "go fast" vessel in international waters about 30 nautical miles southeast of San Andrés Island, 1 46 U.S.C. § 70502(d)(1) was amended on December 23, 2022. See James M. Inhofe National Defense Authorization Act for Fiscal Year 2023, Pub. L. No. 117-263, § 11519, 136 Stat. 2395, 4142 (2022). That amendment, which added § 70502(d)(1)(D), is not relevant to this case. 2 46 U.S.C. § 70504(b)(1) states: "Venue. -- A person violating section 70503 . . . shall be tried in the district in which such offense was committed." 46 U.S.C. § 70506(a) states: "Violations. -- A person violating paragraph (1) of section 70503(a) of this title shall be punished as provided in section 1010 of the Comprehensive Drug Abuse Prevention and Control Act of 1970 (21 U.S.C. 960). However, if the offense is a second or subsequent offense as provided in section 1012(b) of that Act (21 U.S.C. 962(b)), the person shall be punished as provided in section 1012 of that Act (21 U.S.C. 962)." 46 U.S.C. § 70506(b) states: "Attempts and conspiracies. -- A person attempting or conspiring to violate section 70503 of this title is subject to the same penalties as provided for violating section 70503." - 6 - Colombia. The crew reported observing persons on the vessel throwing packages and fuel barrels into the water. The crew noted that a cloud of white powder was seen escaping from one of the packages. The crew "also observed what was believed to be a Costa Rica flag painted on the port bow of the go fast" vessel. The United States Coast Guard dispatched a Boarding Team to intercept the vessel. The Boarding Team commenced "Right to Approach" questioning of the vessel's crew. The vessel's master claimed that the vessel was of Costa Rican nationality. He did not provide the members of the Boarding Team any Costa Rican registration documents,3 and the Boarding Team did not identify any "further indicia of nationality." The Boarding Team proceeded to contact the government of Costa Rica to inquire about the vessel. The government of Costa Rica was unable to "affirmatively and unequivocally assert," § 70502(d)(1)(C), that the vessel was registered with that country. The Boarding Team "determined" that the vessel was "without nationality." The Boarding Team found trace amounts of cocaine after searching the vessel and arrested the three people on board -- specifically, the two defendants in these consolidated appeals, The affidavit makes no reference to a "claim of registry" 3 having been made. - 7 - Dávila-Reyes and Reyes-Valdivia, and a third crew member. The three individuals were taken to the United States's military base at Guantánamo Bay, Cuba before they were transported to Puerto Rico, where they were held pending charges. C. Dávila-Reyes, Reyes-Valdivia, and the third member of the vessel's crew were indicted in the District of Puerto Rico on November 23, 2015. The indictment charged each of the three crew members with two counts of violating the MDLEA while "on board a vessel subject to the jurisdiction of the United States, as defined in Title 46, United States Code, Section 70502(c)(1)(A)." The indictment did not further specify the ground for so deeming the vessel. D. Reyes-Valdivia moved on February 1, 2016, to dismiss the charges. The motion relied on various constitutional grounds. Reyes-Valdivia's motion first contended that the charges must be dismissed because Congress lacked the power under the Felonies Clause to criminalize the underlying conduct. The motion argued that the Felonies Clause does not empower Congress to make it a crime for a foreign national to engage in drug trafficking outside the "territorial jurisdiction" of the United States while aboard a foreign vessel. The motion further contended that § 70502(d)(1)(C)'s definition of a "vessel without nationality" - 8 - "extends jurisdiction over vessels that are not in fact stateless under international law, where the claimed nation of registry fails to unequivocally confirm registry." The motion then asserted that, "[b]ecause the MDLEA's statelessness provision is significantly broader than international law's concept of statelessness, the statute's assertion of jurisdiction over stateless vessels is an invalid exercise of Congress's Article I powers" in that it extends the reach of the MDLEA to persons who are aboard vessels on the high seas that are foreign rather than stateless for purposes of international law. The motion separately contended that the charges must be dismissed pursuant to the Due Process Clause of the Fifth Amendment. See U.S. Const. amend. V. The motion argued that § 70502(d)(1)(A) and § 70502(d)(1)(C) are void for vagueness because neither provision explains the steps that a nation must take either to "den[y]" or "affirmatively and unequivocally assert that the vessel is of its nationality." The motion also took aim at the charges for two additional reasons under the Due Process Clause. First, the motion contended that the indictment violated the Due Process Clause because the MDLEA does not require the government to bear the burden of affirmatively proving that the vessel in question was stateless under international law. Second, the motion contended that the indictment violated the Due Process Clause because it did - 9 - not allege the drugs that the defendants were charged with trafficking were "destined for the United States" and so did not allege any "nexus" between the defendants' allegedly unlawful conduct and the United States.4 Dávila-Reyes joined Reyes-Valdivia's motion. The government opposed Dávila-Reyes and Reyes-Valdivia's joint motion and attached to its brief in opposition decisions from the District of Puerto Rico that had rejected challenges to the MDLEA like those that the defendants' joint motion advanced. The District Court denied the motion in a two-page order. The District Court explained that it had "reviewed, considered and analyzed the applicable statutes, case law and the opinions by other judges" attached to the government's opposition to the motion to dismiss the indictment and "agree[d] with their analyses and conclusions." E. On March 25, 2016, the government filed a motion pursuant to 46 U.S.C. § 70504(a), which provides: "Jurisdiction of the United States with respect to a vessel subject to this chapter is not an element of an offense. Jurisdictional issues arising under this chapter are preliminary questions of law to be determined 4The motion also contended that the MDLEA charges could not be justified under the Treaties Clause, see U.S. Const. art. II, § 2, cl. 2, but neither the defendants nor the government address this argument on appeal and so we need not consider the issue. - 10 - solely by the trial judge." The motion asked the District Court to "find, as a matter of law, that the vessel in question was subject to the jurisdiction of the United States, as defined in Title 46, United States Code, Sections 70502(c)(1)(A) and (d)(1)(C)." The motion also requested that the District Court, "prior to the beginning of testimony in this case, preliminarily [instruct] the jury pursuant to Title 46, United States Code, Section[s] 70502(c)(1)(A) and (d)(1)(C) that the suspect vessel carrying the [d]efendants was a vessel [w]ithout [n]ationality and therefore subject to the jurisdiction of the United States." To support the motion, the government attached an affidavit from the leader of the Boarding Team. The affidavit stated that the master of the vessel initially "claimed . . . that there was no nationality for the vessel," then "later tried to change the claim [of the vessel's nationality] to Costa Rica." The affidavit stated that "a Costa Rican flag [was] painted on the bow" of the vessel. The motion itself asserted that there was no "name, hailing port, or registration numbers on the [vessel's] hull" and that "the vessel was not flying any flag." In further support of the motion, the government attached a certification from the United States Department of State. Under 46 U.S.C. § 70502(d)(2), such a certification is in and of itself conclusive proof as to the response of a country that has been contacted for purposes of determining that a vessel - 11 - is "without nationality" under § 70502(d)(1)(C). The certification explained that the vessel was located by law enforcement 30 nautical miles southeast of San Andrés Island, Colombia; that law enforcement suspected the vessel of illicit drug trafficking because the crew was jettisoning unknown packages in an area where drug trafficking was common; that the master made a claim of Costa Rican nationality; that no registration documents were present on the vessel; and that Costa Rica, when contacted, "could not confirm the vessel's registry." The certification concluded that, "[a]ccordingly, the Government of the United States determined the vessel was "without nationality in accordance with 46 U.S.C. § 70502(d)(1)(C), rend[er]ing the vessel subject to the jurisdiction of the United States, pursuant to 46 U.S.C. § 70502(c)(1)(A)." F. Before the defendants responded to the government's § 70504(a) motion or the District Court ruled on it, all three defendants on April 4, 2016, pleaded guilty to violating the MDLEA.5 Each defendant admitted in his respective plea agreement to: [k]nowingly and intentionally combining, conspiring, confederating and agreeing with others, to commit an offense defined in Title 5The third crew member entered into substantially the same plea agreement as Dávila-Reyes and Reyes-Valdivia but, because he did not appeal his conviction, his case is not before us. - 12 - 46, United States Code, Section 70503, that is: to possess with intent to distribute five (5) kilograms or more of a mixture or substance containing a detectable amount of cocaine, a Schedule II, Narcotic Drug Controlled Substance, on board a vessel subject to the jurisdiction of the United States, as defined in Title 46, United States Code, Section 70502(c)(1)(A). Each defendant also "adopt[ed]" as part of his plea agreement the Government's Version of the Facts, which was attached to the plea agreement. Thus, by signing the plea agreement, each defendant agreed that, as to the Government's Version of the Facts, "the facts therein are accurate in every respect and, had the matter proceeded to trial, that the United States would have proven those facts beyond a reasonable doubt." The Government's Version of the Facts stated in relevant part: A U.S. Coast Guard . . . Boarding Team approached the vessel and commenced Right to Approach . . . questioning. The master claimed Costa Rican nationality for the vessel but provided no registration paperwork and there was no indicia of nationality on the vessel. The government of Costa Rica was approached and responded that it could neither confirm nor refute the registry of the suspect vessel. The vessel was determined to be one without nationality. Dávila-Reyes was sentenced to 120 months of imprisonment on August 2, 2016, and his judgment of conviction was entered that same day. Reyes-Valdivia was sentenced to 70 months of - 13 - imprisonment on August 5, 2016, and his judgment of conviction was also entered that day.6 G. Dávila-Reyes and Reyes-Valdivia each filed a timely notice of appeal from the "judgment" that the District Court had entered in each of their respective cases. Dávila-Reyes's and Reyes-Valdivia's appeals were consolidated. In the defendants' briefing to the panel, the defendants challenged the judgments that the District Court had entered against them under the Felonies Clause and the Due Process Clause. In addition, Dávila-Reyes raised a new argument: Congress lacked the power under the Constitution to criminalize his charged conduct because the vessel that he was aboard was not on the high seas and was instead within the territorial waters of Colombia. The two defendants contended in their briefing to the panel that they had not waived the constitutional claims that they were raising on appeal by entering unconditional guilty pleas in the District Court. They argued that § 70503(e)(1), in referencing the "jurisdiction of the United States," establishes a limitation 6 Reyes-Valdivia also appealed his sentence. The panel affirmed his sentence in its original opinion. That holding was vacated when that opinion was withdrawn, so Reyes-Valdivia's sentencing appeal remains before us. United States v. Dávila- Reyes, 937 F.3d 57, 63-64 (1st Cir. 2019). But Reyes-Valdivia is no longer in custody, and so his sentencing challenge is now moot. See United States v. Suarez-Reyes, 910 F.3d 604, 606 (1st Cir. 2018). - 14 - on the subject matter jurisdiction of courts. On that basis, they contended that they were entitled to raise their various claims on appeal despite their unconditional guilty pleas because the claims implicated the question of whether the District Court had subject matter jurisdiction under Article III to enter the judgments against them. After the parties filed their briefs with the panel, but before oral argument to the panel, the government filed a letter under Federal Rule of Appellate Procedure 28(j) about Class v. United States, 138 S. Ct. 798 (2018). There, the Supreme Court of the United States held that an unconditional guilty plea does not necessarily waive a constitutional challenge to the defendant's statute of conviction. The government argued in the letter that, notwithstanding Class, the defendants were barred from raising their challenges on appeal by their unconditional guilty pleas. The defendants responded with their own Rule 28(j) letter. They contended in their letter that Class established that they had not waived their claims by entering their unconditional guilty pleas. The panel heard oral argument in the defendants' appeals on March 7, 2018. Then, on January 15, 2019, the panel ordered the parties to submit supplemental briefing to address two questions: - 15 - 1. What is the basis for deeming appellants' vessel "a Vessel without nationality" under 4[6] U.S.C. § 70502(d)(1) given that none of the clauses of 46 U.S.C. § 70502(d)(1) appears to apply by its terms? As background, we note that the statements of fact presented in appellants' plea agreements report that the master of appellants' vessel declared Costa Rican nationality, not Costa Rican registry. That declaration renders § 70502(d)(1)(B) inapplicable, and clauses (A) and (C) refer only to claims of registry. 2. Assuming that the circumstances do not permit deeming appellants' vessel one "without nationality" pursuant to any clause of 46 U.S.C. § 70502(d)(1), what other jurisdictional basis supports this prosecution by United States authorities under United States law against appellants -- citizens of Costa Rica who were detained in international waters on a vessel claimed to be of Costa Rican nationality? The parties submitted briefing on the questions. H. In September 2019, the panel -- in its original opinion, which the panel later withdrew when issuing its subsequent opinion -- rejected the challenges that Dávila-Reyes and Reyes- Valdivia had brought under the Felonies Clause and the Due Process Clause to the "judgments" entered against them. See United States v. Dávila-Reyes, 937 F.3d 57, 62-64 (1st Cir. 2019) (Dávila-Reyes I). The panel relied on Class to hold that the defendants' guilty pleas did not "foreclose their right to challenge the constitutionality of the MDLEA." Id. at 61. But the panel ruled against the defendants on the merits based on United States v. - 16 - Cardales, 168 F.3d 548 (1st Cir. 1999), "and the cases reiterating its approach." Dávila-Reyes I, 937 F.3d at 63. The panel explained that those precedents established that the MDLEA was a valid assertion of the United States's protective jurisdiction under international law, given the United States's interest in protecting itself from the baleful effects of drug trafficking. Id. at 62-63. The panel explained that this was so no matter the basis under § 70502(c)(1)(A) of the MDLEA for determining that a defendant was on a "vessel without nationality" on which the government was relying. Thus, the panel explained, this was so notwithstanding the defendants' contention that the MDLEA (per § 70502(d)(1)(C)) permitted a vessel to be so deemed even when it was not stateless for purposes of international law.7 Id. Dávila-Reyes and Reyes-Valdivia petitioned for rehearing en banc from the panel's ruling in October 2019. The petition contended that the defendants' convictions ran afoul of the Felonies Clause and the Due Process Clause. The petition contended on that basis that Cardales should be overruled. The panel did not appear to address Dávila-Reyes' contention 7 that Congress lacked the power to criminalize his conduct because the vessel that he was aboard was not on the high seas. The defendants did not raise the contention in the petition for rehearing en banc that they filed after the panel's original opinion issued. Thus, the argument has been abandoned, and we need not address it here. - 17 - While the petition was pending, our court, sitting en banc, decided United States v. Aybar-Ulloa, 987 F.3d 1 (1st Cir. 2021). In that case, we rejected the defendant's contention that the Felonies Clause did not empower Congress to criminalize his conduct, which involved alleged drug trafficking on the high seas while aboard a vessel "without nationality" under § 70502(c)(1)(A). Aybar-Ulloa did not rely in so holding, as Cardales and the panel in Dávila-Reyes I had, on the United States's assertion of protective jurisdiction under international law. Aybar-Ulloa relied instead on the ground that Congress had the power under the Felonies Clause to make it a crime for a foreign national to engage in drug trafficking on the high seas while aboard a vessel that was stateless under international law. Id. at 4-5. Aybar-Ulloa explained that the MDLEA conviction at issue there did not exceed Congress's Felonies Clause power because the defendant in that case did not dispute that he was a foreign national who was aboard a vessel at the time of his drug trafficking that was both on the high seas and stateless for purposes of international law. Id. at 5-6. Following our en banc decision in Aybar-Ulloa, the panel in Dávila-Reyes's and Reyes-Valdivia's cases construed the pending petition for rehearing en banc as a petition for panel rehearing, granted the petition, and vacated the panel's September 2019 - 18 - opinion. The panel explained that it had "concluded that the en banc decision in [Aybar-Ulloa] has diminished the force of this circuit's precedent on the protective principle such that the panel . . . deem[ed] it appropriate to address appellants' contention that the government improperly deemed their vessel stateless." United States v. Dávila-Reyes, No. 16-2089, 2021 WL 5276369 (1st Cir. Mar. 17, 2021). The panel issued a new decision in January 2022 that vacated the defendants' convictions and dismissed the charges against them. See United States v. Dávila-Reyes, 23 F.4th 153 (1st Cir. 2022) (Dávila-Reyes II). A majority of the panel explained that Class allowed the defendants to press their constitutional claims despite their unconditional guilty pleas. Id. at 162-164. Then, the majority turned to the merits. The majority reasoned that Congress lacks the power under the Felonies Clause to criminalize a foreign national's drug trafficking in international waters unless the United States's assertion of regulatory jurisdiction over that foreign national would be permissible under international law. Id. at 173-83. The majority then explained that, although Aybar-Ulloa held that international law permits the United States to assert such regulatory jurisdiction when the foreign national is aboard a vessel on the high seas that is stateless under international law, a vessel cannot be deemed stateless under international law merely - 19 - because, as § 70502(d)(1)(C) provides, a foreign nation whose nationality the vessel's master claims for the vessel "fail[s] to supply an 'affirmative and unequivocal' confirmation of nationality." Id. at 186-95 (cleaned up). And, the majority concluded, the defendants' charges and convictions necessarily depended on the application of § 70502(d)(1)(C) -- and on no other basis -- to deem the vessel that they were aboard at the time of their MDLEA violations to be "without nationality" under § 70502(c)(1)(A). Id. at 162-65. In so holding, the majority acknowledged that the government had argued in its supplemental briefing to the panel that the defendants' vessel "could have been deemed without nationality based on . . . jurisdictional theories" other than application of § 70502(d)(1)(C). Id. at 164-65. These alternative bases included that the vessel's master "fail[ed] to produce registration paperwork or otherwise substantiate his verbal claim of nationality." Id. at 164. But the majority concluded that "it [was] simply too late for the government to proffer alternative bases for jurisdiction" because those bases were "not the basis on which the government relied to arrest and prosecute appellants, and to obtain their guilty pleas." Id. at 164-65. Thus, the majority explained, the defendants' charges and convictions exceeded Congress's power, including under the Felonies Clause, because a vessel deemed to be "without - 20 - nationality" under § 70502(c)(1)(A) solely by application of § 70502(d)(1)(C) is not stateless under international law. Id. at 194-95. Accordingly, the panel ordered the defendants' convictions vacated and the charges against them dismissed. Id. at 195. Then-Chief Judge Howard issued an opinion concurring in the judgment. Id. at 195-96 (Howard, C.J., concurring in the result). He explained that the MDLEA provides that a vessel is "without nationality" under § 70502(c)(1)(A) when, as § 70502(d)(1)(C) provides, "the master or individual in charge makes a claim of registry and for which the claimed nation of registry does not affirmatively and unequivocally assert that the vessel is of its nationality." Id. But, he concluded, the master of the vessel in question in Dávila-Reyes and Reyes-Valdivia's cases had made a claim of Costa Rican "nationality" rather than Costa Rican "registry." Id. Then-Chief Judge Howard explained that as a result the conclusive presumption of a vessel being "without nationality" that § 70502(d)(1)(C) sets forth had no application in the defendants' cases and that, for that statutory reason alone, the defendants' convictions must be vacated and the charges against them in the indictment dismissed.8 Id. at 196. 8 Then-ChiefJudge Howard noted that the defendants' statutory contention arguably was waived because the defendants did not brief the statutory argument until ordered to by the panel. But he - 21 - Following the panel's decision, the United States petitioned for rehearing en banc. We granted the petition in July 2022; vacated the panel's February 2022 opinion; ordered supplemental briefing, which the parties then supplied; and heard oral argument. II. The defendants seek to challenge their convictions on various grounds despite their unconditional guilty pleas. Thus, we confront a threshold question: Did the defendants' guilty pleas waive the various challenges that they seek to have us address? Insofar as we conclude that the defendants' guilty pleas did not, we then also confront one further threshold question: What standard of review applies to each of the challenges that the defendants bring on appeal? The defendants contend to us, as they did to the panel, that their unconditional guilty pleas did not waive their challenges because the challenges concern whether their vessel was "subject to the jurisdiction of the United States" under the MDLEA. The defendants contend that this requirement in the MDLEA places a limit on a federal court's subject matter jurisdiction and thus a federal court's jurisdiction under Article III of the United suggested that the supplemental briefing may have been sufficient to "bypass [this] appellate waiver." Dávila-Reyes II, 23 F.4th at 196 n.65. - 22 - States Constitution. In consequence, the defendants contend, their challenges take aim at the Article III jurisdiction of the District Court and so are both not waivable by an unconditional guilty plea and subject to de novo (rather than plain error) review whether their challenges were raised below or not. The defendants also contend, in the alternative, that their guilty pleas did not waive their challenges for a different reason. Here, they rely on Class. We explain in Part III why we reject the defendants' Article III-based ground for both permitting their challenges to their convictions to go forward despite their unconditional guilty pleas and reviewing those challenges de novo even if the challenges were not raised below. We then address in Part IV the defendants' Class-based ground for permitting their challenges to go forward. There, we explain that, even assuming that under Class the defendants' challenges are not waived, we must reject them, either because they have no merit under de novo review or because they - 23 - are subject to the plain error standard of review and cannot meet it.9 III. The defendants contend that their challenges take aim at the subject matter jurisdiction of the District Court because the challenges take aim at the basis for concluding that their vessel was "subject to the jurisdiction of the United States" for purposes of the MDLEA. This phrase appears in several sections of the MDLEA, although the defendants and the government focus chiefly on its use in § 70502(c)(1) and § 70504 of the MDLEA. The defendants' and the government's contentions are best understood, however, to be addressing the use of the phrase in § 70503(e)(1). That provision is the operative one, as it provides that a "vessel subject to the jurisdiction of the United States" is a "covered The government separately contends that both Dávila-Reyes's 9 and Reyes-Valdivia's appeals are barred by the waiver of appeal contained in each of their plea agreements. We note that Reyes- Valdivia's appeal waiver was predicated on his receipt of a sentence of no more than 57 months of imprisonment. Because he received a 70-month prison sentence, that waiver appears to be unenforceable. In any event, we may assume for present purposes that neither waiver is a bar to these appeals because the defendants' challenges to their indictment and convictions fail on other grounds. - 24 - vessel" and so the type of vessel that a person must be "on board" to violate the MDLEA under § 70503(a).10 We may assume that the defendants are right to contend that their various challenges on appeal implicate § 70503(e)(1), because we agree with the government that, even if the challenges do, the challenges do not implicate the subject matter jurisdiction of the District Court, because § 70503(e)(1) does not impose a limitation on a court's subject matter jurisdiction. Accordingly, we reject the defendants' Article III-based arguments as to both whether their guilty pleas waived their challenges and why the standard of review that applies to those challenges is de novo regardless of whether the challenges were raised below. A. The defendants acknowledge up front that, in United States v. González, 311 F.3d 440 (1st Cir. 2002), a panel of this court held that § 70503(e)(1) does not establish a limitation on a court's subject matter jurisdiction. But the defendants contend that González was wrong to so hold -- as some other circuits have also concluded, see United States v. Miranda, 780 F.3d 1185, 1191- 97 (D.C. Cir. 2015); United States v. Tinoco, 304 F.3d 1088, 1106 10 To be clear, our analysis would be no different if we treated the parties as addressing § 70502(c)(1) or § 70504 rather than § 70503(e)(1). - 25 - (11th Cir. 2002); United States v. Bustos-Useche, 273 F.3d 622, 626 (5th Cir. 2001) -- and that we should overrule that precedent. The Second Circuit has comprehensively reviewed the relevant post-González precedent, however, and sided with González. See United States v. Prado, 933 F.3d 121, 132-51 (2nd Cir. 2019). We conclude that the Second Circuit's reasoning is persuasive. 1. Congress vested "courts of the United States" (emphasis added) with "original jurisdiction . . . of all offenses against the laws of the United States" in 18 U.S.C. § 3231. Thus, the defendants need to show that § 70503(e)(1) of the MDLEA, by referring to the "jurisdiction of the United States" (emphasis added), limits the otherwise operative grant of subject matter jurisdiction to federal courts over federal criminal prosecutions that 18 U.S.C. § 3231 sets forth. See Prado, 933 F.3d at 134-35. The Supreme Court has explained in a case that post- dates González that "[i]f the Legislature clearly states that a threshold limitation on a statute's scope shall count as jurisdictional," then the limitation concerns the Article III subject matter jurisdiction of the courts. Arbaugh v. Y&H Corp., 546 U.S. 500, 515 (2006). But the Court went on to say in that case that "when Congress does not rank a statutory limitation on coverage as jurisdictional," the limitation does not concern the - 26 - Article III subject matter jurisdiction of the courts. Id. at 516. Here, of course, the provision in question does use the word "jurisdiction." But, as Prado emphasized, 933 F.3d at 132, and González itself noted, "[t]he term 'jurisdiction' is notoriously malleable and is used in a variety of contexts . . . that have nothing whatever to do with the court's subject matter jurisdiction," 311 F.3d at 443 (emphasis removed). We therefore find it telling that, as Arbaugh acknowledges, Congress knows how to write statutes that provide for or limit the subject matter jurisdiction of courts by expressly referring to cases or controversies heard by the courts themselves. See, e.g., 28 U.S.C. § 1331 ("The district courts shall have original jurisdiction of all civil actions arising under the Constitution, laws, or treaties of the United States."); 7 U.S.C. § 2707(e)(3) ("[T]he several district courts of the United States are hereby vested with jurisdiction to entertain such suits [that pertain to orders of the Egg Board] regardless of the amount in controversy."); 16 U.S.C. § 814 ("United States district courts shall only have jurisdiction of cases [concerning suits regarding the use of eminent domain to obtain land to construct a dam or certain public waterways] when the amount claimed by the owner of the property to be condemned exceeds $3,000."). - 27 - This past legislative practice is telling because the provision at issue here does not refer to courts having "jurisdiction" over "actions," "suits," or their equivalent. It refers only to a "vessel" being "subject to . . . jurisdiction" and to "the United States" -- rather than a court -- having "jurisdiction" over the vessel. Thus, § 70503(e)(1) does not by using the term "jurisdiction" impose a limitation on the Article III subject matter jurisdiction of courts. It instead defines the scope of the regulatory jurisdiction that Congress is asserting through the MDLEA. Section 70503(b) supports the same understanding. That section, titled "Extension beyond territorial jurisdiction," (emphasis added), clarifies that the substantive prohibition that is set forth in § 70503(a) -- the provision that invokes the phrase "covered vessel" -- "applies even though the act is committed outside the territorial jurisdiction of the United States" (emphasis added). Because the phrase "jurisdiction of the United States" in § 70503(b) clearly is not referring to the jurisdiction of a court, we see no reason to read that same phrase in § 70503(e)(1) to be doing so. See Prado, 933 F.3d at 142-44. Other sections of Title 46 of the United States Code, we note, also use the phrase "jurisdiction of the United States" in contexts that make clear that those sections are not referring to the power of courts to adjudicate disputes. See Prado, 933 F.3d - 28 - at 143 n.12 (collecting statutes). By contrast, § 70505 of the MDLEA states that "[a] failure to comply with international law does not divest a court of jurisdiction and is not a defense to a proceeding under this chapter." Given that § 70503(e)(1) refers only to the "jurisdiction of the United States" over a "vessel," we see no basis for reading it as if it, like § 70505, were referring to the "jurisdiction" of a "court" over a "proceeding." In sum, the MDLEA's statutory text provides no support for the conclusion that Congress intended the phrase "subject to the jurisdiction of the United States" in § 70503(e)(1) to impose a limitation on the subject matter jurisdiction of courts. Nor do we see any basis for concluding that Congress's use of the phrase constitutes the kind of clear statement required by Arbaugh to impose such a limitation. Accordingly, we see no basis for breaking with our ruling in González. 2. We recognize that the D.C. Circuit, in concluding otherwise in Miranda, noted that the phrase "[j]urisdiction of the United States" also appears in § 70504(a) of the MDLEA, which is titled "Jurisdiction and venue." 780 F.3d at 1196. The D.C. Circuit concluded from the inclusion of that phrase in a provision so titled that the phrase as it appears in § 70503(e)(1) must be a limitation on the subject matter jurisdiction of courts, - 29 - notwithstanding that § 70503(e)(1) is not similarly titled.11 We are not persuaded. The precursor to § 70504(a), which bore the same title to which the D.C. Circuit gave such interpretive weight, was 46 U.S.C. app. § 1903(f) (1996). That provision, however, had a companion provision, 46 U.S.C. app. § 1903(d) (1996). And that companion provision was titled "Claim of failure to comply with international law; standing; jurisdiction of court." (emphasis added). Thus, the relevant statutory history reveals that the "Jurisdiction and venue" title to which the D.C. Circuit gave such import made no reference to the "jurisdiction of court" at a time when the title to a companion provision expressly did. That makes it difficult to conclude that the "Jurisdiction and venue" title demonstrates that the phrase "jurisdiction of the United States" was intended to set a limit on the "jurisdiction of court[s]." Congress did later drop "jurisdiction of court" from the title of the companion provision, which now appears in the MDLEA as § 70505. But Congress made that title change as part of a 2006 effort to "reorganize[] and restate[]" the MDLEA and so to "codif[y] existing law rather than creat[e] new law." Miranda, 11 Neither the Eleventh Circuit in Tinoco nor the Fifth Circuit in Bustos-Useche presents any arguments that Miranda did not rely on in determining that § 70503(e)(1) implicates the subject matter jurisdiction of courts. - 30 - 780 F.3d at 1196 (quoting H.R. Rep., No. 109-170, at 2 (2005)). We thus do not see how we may infer from the change to the title of § 70505 that Congress intended the phrase "jurisdiction of the United States" in § 70503(e)(1) to set a subject matter limitation on the jurisdiction of a court, given that § 70503(e)(1) itself makes no mention of courts at all. 3. The D.C. Circuit also concluded in Miranda that the phrase "jurisdiction of the United States" in § 70503(e)(1) must be construed to limit the Article III subject matter jurisdiction of courts for another reason. The D.C. Circuit reasoned that Congress would have wanted the question of whether a vessel was "subject to the jurisdiction of the United States" to be non- waivable "in order to minimize the extent to which the MDLEA's application might otherwise cause friction with foreign nations" by ensuring that the defendants were properly subject to prosecution in the United States "in every case -- and at every level of review." 780 F.3d at 1193-94. But the relevant statutory text, as we have explained, is to the contrary, and nothing in the legislative history shows that the text does not mean what it appears to say. Prado, 933 F.3d at 139-40. In fact, § 70505 appears to reflect a contrary congressional understanding to the one posited in Miranda: It provides that "[a] failure to comply with international law does - 31 - not divest a court of jurisdiction and is not a defense to a proceeding under this chapter." 4. The D.C. Circuit did also imply that the constitutional avoidance canon supports construing the provision of the MDLEA at issue to limit the Article III subject matter jurisdiction of courts. The D.C. Circuit explained that, if § 70503(e)(1) establishes an element of the crime, rather than a limitation on the subject matter jurisdiction of courts, then the statute may run afoul of the Sixth Amendment to the United States Constitution. See Miranda, 780 F.3d at 1195-96; see also González, 311 F.3d at 444. The notion is that, if § 70503(e)(1) were not construed to establish a limitation on the subject matter jurisdiction of a court, then that provision of the MDLEA would establish an element of the offense that would have to be proved to a jury beyond a reasonable doubt. See Torres v. Lynch, 578 U.S. 452, 467 (2016) ("Both [the substantive and jurisdictional] elements [of a crime] must be proved to a jury beyond a reasonable doubt."). Section 70504(a), however, provides that the determination as to whether a vessel is "subject to the jurisdiction of the United States" need be made only by a court -- rather than a jury. And this determination, we have held, need be made only by a preponderance of the evidence rather than beyond a reasonable - 32 - doubt. United States v. Matos-Luchi, 627 F.3d 1, 5 (1st Cir. 2010) (holding that a vessel may be shown to be "without nationality" by "a preponderance of the evidence"). The defendants do not themselves invoke the constitutional avoidance canon in pressing their Article III-based arguments to us, however. And seemingly for good reason. The canon applies only if there is an ambiguity in the relevant respect, see Nielsen v. Preap, 139 S. Ct. 954, 972 (2019) (constitutional avoidance is "irrelevant" if text of statute is clear); Jennings v. Rodriguez, 138 S. Ct. 830, 842 (2018) (cautioning that the canon of constitutional avoidance "comes into play only when, after the application of ordinary textual analysis, the statute is found to be susceptible of more than one construction" (quoting Clark v. Martinez, 543 U.S. 371, 385 (2005))), and, as we have explained, there is none here. Moreover, a majority of a panel of this court has held that even if § 70503(e)(1) does not implicate the Article III jurisdiction of a court, no Sixth Amendment issue arises. United States v. Vilches-Navarrete, 523 F.3d 1, 19-23 (1st Cir. 2008) (Lynch and Howard, JJ., concurring). And, despite the law of the circuit established by that ruling, neither defendant makes any argument to us as to why we should reconsider our precedent on that score. - 33 - B. For all these reasons, we decline to depart from our holding in González that § 70503(e)(1) merely sets a limit on the scope of the conduct that the MDLEA itself criminalizes. As a result, we reject the defendants' Article III-jurisdiction-based argument for contending both that their unconditional guilty pleas did not waive the challenges to their convictions that they make on appeal and that we must review all those challenges de novo regardless of whether they were raised below. IV. The defendants separately contend that, in consequence of Class, their unconditional guilty pleas did not waive the challenges that they now advance on appeal. Class concerned a defendant who had entered an unconditional guilty plea and then appealed his conviction on the ground that the statute under which he was convicted violated the Constitution. The Supreme Court allowed the defendant's challenge to proceed, as against a claim that the challenge had been waived by his unconditional guilty plea, because the defendant was pressing a challenge to "'the very power of the State' to prosecute" him. Class, 138 S. Ct. at 803 (quoting Blackledge v. Perry, 417 U.S. 21, 30 (1974)); see also Menna v. New York, 423 U.S. 61 (1975). Class made clear the limited nature of this exception to the usual rule that an unconditional guilty plea waives challenges - 34 - to the defendant's conviction. It explained that the exception applies only to a challenge to the "constitutionality of the statute of conviction," 138 S. Ct. at 803, and then only when the challenge "does not in any way deny that [the defendant] engaged in the conduct to which he admitted" and does not "contradict the terms of the indictment or the written plea agreement," id. at 804-05. Moreover, the Court explained the challenge must, "'judged on its face' based upon the existing record," be of the sort that, if successful, "would extinguish the government's power to 'constitutionally prosecute' the defendant." Id. at 806 (quoting United States v. Broce, 488 U.S. 563, 575 (1989)). Dávila-Reyes and Reyes-Valdivia contend that Class encompasses their challenges on appeal, while the government disagrees. The government contends that the defendants are challenging the MDLEA's constitutionality only as it has been applied to them in their specific cases and that such as-applied constitutional challenges do not fall within Class. The government further contends that Class does not apply here because the defendants' challenges on appeal necessarily seek to deny what the defendants admitted in pleading guilty unconditionally, given that in so pleading the defendants admitted both that they were aboard "a vessel subject to the jurisdiction of the United States" and to certain facts that bear on that very determination. But, as we will explain, even if we were to assume that Class permits the - 35 - defendants to raise any or all their challenges on appeal despite their unconditional guilty pleas, the challenges still would fail under the standard of review that we conclude applies to each of those challenges. A. We begin with the defendants' constitutional claim that Congress has no power under the Felonies Clause to criminalize their charged conduct. The defendants do not spell out the claim as clearly as they might, but we understand it to come to us in two distinct variants. The first variant tracks the Felonies Clause-based challenge that the defendants made in their motion to dismiss the indictment that they filed in the District Court. Like that challenge, we understand this variant also to take aim at the indictment and to do so on the ground that it sets forth charges that are asserted to be beyond Congress's power to authorize under the Felonies Clause. The second variant, by contrast, does not depend on an any assertion that the indictment itself is defective because it sets forth charges that exceed Congress's power under the Felonies Clause. This variant of the challenge contends instead that, even if the indictment is unassailable, the convictions cannot stand because the nature of the post-indictment record is such that it - 36 - shows that the convictions violate the Felonies Clause. We consider each variant of the Felonies Clause-based claim in turn. 1. The indictment-focused variant depends on the following chain of logic. The Felonies Clause does not give Congress the power to criminalize drug trafficking by persons on a vessel on the high seas if the United States would not have regulatory jurisdiction over those persons under international law. Because international law does not permit the United States to exercise regulatory jurisdiction over foreign nationals engaged in drug trafficking on the high seas while aboard foreign vessels, the United States could criminalize the defendants' charged conduct under the Felonies Clause only if the defendants were aboard a vessel on the high seas that was stateless under international law. A vessel may not be deemed stateless under international law, however, simply because the nation to which the vessel's master has claimed that it belongs fails to "affirmatively and unequivocally assert," § 70502(d)(1)(C), that the vessel is registered with that nation. Yet, the indictment charged that the vessel that the defendants were aboard was "without nationality" under § 70502(c)(1)(A) solely based on the operation of § 70502(d)(1)(C). Thus, the indictment necessarily charged the defendants with violating the MDLEA on a basis that is not constitutional, given that § 70502(d)(1)(C) provides that "a - 37 - vessel aboard which the master or individual in charge makes a claim of registry and for which the claimed nation of registry does not affirmatively and unequivocally assert that the vessel is of its nationality" is a vessel that is "without nationality" for the purposes of the MDLEA. Because the defendants advanced this exact claim in their motion to dismiss the indictment, it is preserved, such that our review of the challenge is de novo. See United States v. Savarese, 686 F.3d 1, 6 (1st. Cir 2012). But the government contends that the challenge nonetheless fails, and we agree. The reason is simple: The indictment cannot be read, even on de novo review, to rely exclusively on § 70502(d)(1)(C) in charging the defendants with having been aboard a "vessel without nationality" under § 70502(c)(1)(A). Thus, the challenge rests on a faulty premise about the basis for the indictment's charge that the defendants were on a vessel that was "without nationality." The indictment states with respect to whether the defendants were aboard a "vessel subject to the jurisdiction of the United States" only that they were aboard a vessel "as defined in Title 46, United States Code, Section 70502(c)(1)(A)." The indictment thus makes no reference to § 70502(d)(1)(C), let alone solely to that provision. Nor does the indictment refer to any other provision of the MDLEA that bears on the question of whether - 38 - the vessel was "subject to the jurisdiction of the United States" because it was "without nationality." In addition, the indictment alleges no facts that could be understood to limit to § 70502(d)(1)(C) the permissible bases for finding the vessel in question to be "without nationality" under § 70502(c)(1)(A). For example, the indictment makes no reference to any facts that implicate § 70502(d)(1)(C), such as to the master of the vessel having made a "claim of registry" (or even a "claim of nationality") or the United States having attempted unsuccessfully to confirm the vessel's registration with another country. Moreover, the defendants do not dispute that a vessel may be shown to be a "vessel without nationality" under § 70502(c)(1)(A) -- the one "jurisdictional" provision of the MDLEA that the indictment does mention -- through means other than the application of § 70502(d)(1)(C). Nor do we see how the defendants could do so. As a panel of this court explained in Matos-Luchi, the use of the word "includes" in § 70502(d)(1) makes clear that "the listed examples" set forth in that section "do not exhaust the scope of [§] 70502(d)" in defining a "vessel without nationality." 627 F.3d at 4. Moreover, Matos-Luchi explained that a vessel may be determined to be "without nationality" under § 70502(c)(1)(A) through a means other than application of any of the subsection of - 39 - § 70502(d)(1) -- namely, when a vessel is not "entitled to fly[] the flag of a State." 627 F.3d at 6 (quoting Molvan v. Att'y-Gen. for Palestine, [1948] A.C. 351 (P.C.) 369-70) (cleaned up). And Matos-Luchi also described that standard as a proper one for determining whether a vessel is stateless for purposes of international law. See id.; see also United States v. Rosero, 42 F.3d 166, 171 (3d Cir. 1994) ("Under international law, 'ships have the nationality of the State whose flag they are entitled to fly.'" (quoting Convention on the High Seas of 1958 art. 5(1), Apr. 29, 1958, 13 U.S.T. 2312, 450 U.N.T.S. 11) (cleaned up)). Because the defendants do not contend that Matos-Luchi was wrong on any of these counts, they fail to explain why the indictment on its face would not permit the government to show that the defendants' vessel was not authorized to fly the flag of any state and so was "without nationality" under § 70502(c)(1)(A) -- and stateless under international law -- for reasons independent of the vessel being the kind of vessel that § 70502(d)(1)(C) describes. See United States v. Stepanets, 879 F.3d 367, 372 (1st Cir. 2018) ("[T]he government need not recite all of its evidence in the indictment." (quoting United States v. Innamorati, 996 F.2d 456, 477 (1st Cir. 1993))). Thus, we conclude that, even on de - 40 - novo review, the first variant of the defendants' Felonies Clause- based challenge fails.12 2. We turn, then, to the other variant of the defendant's Felonies Clause-based challenge. Here, the defendants contend that, even if the indictment is not dependent on § 70502(d)(1)(C), their convictions still violate the Felonies Clause. We are not persuaded by this variant of the defendants' Felonies Clause-based challenge, however, given the standard of review that we conclude applies to it. a. The defendants do not dispute that, as we held in United States v. Ríos-Rivera, 913 F.3d 38, 41-43 (1st Cir. 2019), a constitutional claim that is raised on appeal pursuant to Class is subject to review only for plain error if it was not raised below. Thus, our review of the second variant of the defendants' Felonies Clause-based claim is only for plain error if this variant is being raised for the first time on appeal. To determine whether this variant of the claim is being newly raised, as the government contends it is, we must attend to 12 The dissent does not take issue with any aspect of the description of the indictment that we have set forth above or with the proposition that a vessel may be deemed to be "without nationality" under § 70502(c)(1)(A) on a ground other than § 70502(d)(1)(C). - 41 - the fact that, in pressing this variant of the Felonies Clause- based challenge, the defendants are necessarily taking issue with the import that the government ascribes to the admissions that the defendants made in pleading guilty. That is because the government contends that those admissions provide a basis independent of § 70502(d)(1)(C) for deeming the defendants' vessel to be both "without nationality" under § 70502(c)(1)(A) and stateless under international law. In particular, the government contends that under our decision in Matos-Luchi the factual admissions that the defendants made in pleading guilty in and of themselves suffice to show that the defendants' vessel was not "entitled to fly[] the flag of a State," 627 F.3d at 6, and so was both "without nationality" under the MDLEA and stateless under international law for reasons independent of the operation of § 70502(d)(1)(C). Those admissions are that the sole basis for claiming the vessel had a foreign nationality was the oral claim of that nationality made by the vessel's master and that this oral claim of foreign nationality for the vessel was wholly uncorroborated. Thus, the government contends, to succeed on their Felonies Clause-based challenge, the defendants need to do more than show that § 70502(d)(1)(C) does not provide a basis for deeming a vessel to be stateless under international law. The government contends that the defendants also need to explain why - 42 - the factual admissions regarding the wholly uncorroborated nature of the oral claim of the vessel's foreign nationality that the defendants made in pleading guilty do not themselves provide an independent basis under Matos-Luchi for deeming their vessel "without nationality" as a statutory matter and stateless as an international law matter. Otherwise, the government contends, the defendants will have failed to show that the convictions violate the Felonies Clause because the defendants will have failed to show that the vessel was not in fact stateless under international law. But, in challenging the indictment in the District Court under the Felonies Clause, the defendants obviously did not purport to address the legal significance under Matos-Luchi of any of the factual admissions that they made in their plea agreements regarding the wholly uncorroborated nature of the oral claim of the vessel's foreign nationality to which the government now directs our attention. Indeed, at that time, those factual admissions had not even been made by the defendants, as the defendants had not at that time entered into any plea agreements. Rather, at that time, the defendants were merely taking aim at the indictment itself on the ground that the indictment was dependent solely on § 70502(d)(1)(C) based on what the indictment alone provided. Nor did the defendants at any other time or in any other filing in the District Court make any argument as to the legal - 43 - import of the facts to which they admitted by entering into their plea agreements. For these reasons, we conclude that the government is right that our review of the defendants' Felonies Clause-based challenge to the merits of their convictions is only for plain error insofar as that challenge does not take aim only at the indictment and instead addresses the relevance under Matos-Luchi of the defendants' post-indictment factual admissions. See Ríos- Rivera, 913 F.3d at 41-43; cf. United States v. Caraballo– Rodriguez, 480 F.3d 62, 68-76 (1st Cir. 2007) (applying plain error review to a challenge to the factual basis for a plea predicated on a challenge to the scope of the statute of conviction). And, as we will explain, we conclude that the defendants have failed to satisfy the second prong of the plain error standard with respect to that aspect of the challenge, given our reasoning in Matos- Luchi about when a vessel may be deemed to be "without nationality" under the MDLEA and stateless for international law purposes. See United States v. Pérez-Rodríguez, 13 F.4th 1, 16 (1st Cir. 2021) (explaining that, to satisfy the plain error standard, the defendant must show not only that "an error occurred" but also that the error "was clear or obvious," "affected the[ir] substantial rights" and "seriously impaired the fairness, - 44 - integrity, or public reputation of judicial proceedings" (quoting United States v. Duarte, 246 F.3d 56, 60 (1st Cir. 2001))). b. We begin with the defendants' contention that the government is wrong to contend based on Matos-Luchi that the factual admissions in the plea agreements concerning the wholly uncorroborated nature of the oral claim of the vessel's foreign nationality provide a basis for deeming the defendants' vessel to be "without nationality" under § 70502(c)(1)(A) other than by the operation of § 70502(d)(1)(C). The government's contention on that score proceeds as follows. The government points out that the defendants, in admitting to the Government's Version of the Facts through the plea agreements, necessarily admitted both that their vessel had no registration paperwork and that the vessel had no other indicia of nationality on board.13 The government then contends that -- at least when those factual admissions are considered alongside the defendants' admission that Costa Rica could not confirm the vessel's registry -- the post-indictment record shows that there is a factual basis for finding under Matos-Luchi that the The fact that the vessel's master originally claimed the 13 vessel had no nationality before asserting that it had Costa Rican nationality does not appear in the Government's Version of the Facts to which the defendants agreed when entering their guilty pleas. We thus do not consider that fact in addressing the merits of the defendants' challenges to their convictions. - 45 - defendants' vessel was "without nationality" under § 70502(c)(1)(A). It thus follows, according to the government, that at the time of their pleas their vessel could have been deemed to have been "without nationality" under § 70502(c)(1)(A) solely based on § 70502(d)(1)(C). The defendants' admissions in pleading guilty establish that there is no corroboration whatsoever for the oral claim of the vessel's foreign nationality, even though that oral claim supplies the sole basis for the defendants' contention that the vessel has such a nationality. In consequence, it is not clear or obvious that on the record as it stood at the time of the pleas the defendants' vessel could be deemed to have been "without nationality" under § 70502(c)(1)(A) solely based on § 70502(d)(1)(C) and not also based on the rationale set forth in Matos-Luchi.14 Matos-Luchi explained in relevant part that "[u]nder international law, every vessel must sail under the flag of one and only one state; those that sail under no flag or more than one 14 The affidavits filed in support of the criminal complaint and the government's motion requesting that the District Court declare the vessel to be "subject to the jurisdiction of the United States" both included references to a Costa Rican flag painted on the vessel's hull. But the defendants cannot now assert that fact to corroborate the claim that the vessel was of Costa Rican nationality, because that assertion would contradict the statement in the Government's Version of the Facts that "there was no indicia of nationality on the vessel." See Class, 138 S. Ct. at 804. - 46 - flag enjoy no legal protection." 627 F.3d at 5. Matos-Luchi further explained that "[b]y custom, a vessel claims nationality by flying the flag of the nation with which it is affiliated or carrying papers showing it to be registered with that nation." Id. True, Matos-Luchi did also explain that "[w]ithout a flag or papers, a vessel may also traditionally make an oral claim of nationality when a proper demand is made," while noting that the MDLEA recognized as much in its provision defining what constitutes a "vessel without nationality." Id. But Matos-Luchi then went on to note that "[a]lthough enforcement jurisdiction presumptively lies with the flag state, '[i]t is not enough that a vessel have a nationality; she must claim it and be in a position to provide evidence of it.'" Id. at 6 (citation omitted) (emphasis added) (quoting Andrew W. Anderson, Jurisdiction over Stateless Vessels on the High Seas: An Appraisal Under Domestic and International Law, 13 J. Mar. L. & Com. 323, 341 (1982)). Moreover, Matos-Luchi added that the MDLEA follows this approach "energetically." Id. at 6. It explained in that regard that, because "[p]ractically every vessel, including the legendary Flying Dutchman, has links with some country[,] . . . the stateless vessel concept in the MDLEA and in international law is designed prudentially." Id. And so, according to Matos-Luchi, under both § 70502(c)(1)(A) and international law, "[t]he - 47 - controlling question is whether at the point at which the authorities confront the vessel, it bears the insignia or papers of a national vessel or its master is prepared to make an affirmative and sustainable claim of nationality." Id. (emphasis added); see also Miranda, 780 F.3d at 1197-98 (affirming finding that a vessel was "without nationality" when factual admissions accompanying guilty pleas included that the vessel was not registered with a foreign nation, did not fly the flag of any nation, and carried no registration paperwork). The defendants do contend that these statements from Matos-Luchi regarding the "controlling question" in determining whether a vessel is "without nationality" under the MDLEA are nonbinding dicta. But we do not see why that matters on plain error review, at least given the well-considered nature of the dicta. See United States v. Cortés–Medina, 819 F.3d 566, 570 (1st Cir. 2016) (holding that a decision was not plainly erroneous when it was supported by dicta in our circuit precedent). The defendants separately contend that, in any event, two precedents demonstrate that an oral claim of nationality is, even when wholly uncorroborated, enough to ensure that a vessel has a nationality and so is not "without nationality" under - 48 - § 70502(c)(1)(A). But, in the face of Matos-Luchi, neither precedent suffices to show that is clearly or obviously so. The first case is Rosero, 42 F.3d 166, which the defendants assert rejects the kind of "totality of the evidence" test that they contend would have to be endorsed to deem their vessel "without nationality" solely based on the uncorroborated nature of the vessel's master's oral claim of nationality. But Rosero is an out-of-circuit ruling that also pre-dates key changes that were made to the MDLEA by the time of Matos-Luchi. Rosero thus addressed only the validity of jury instructions15 that permitted a finding beyond a reasonable doubt that a vessel is "without nationality" under the MDLEA. Id. at 171–72. As a result, it did not purport to address the question that we confront here: Are the facts in question sufficient to show by a preponderance of the evidence that the vessel at issue was a "vessel without nationality" under § 70502(c)(1)(A)? See Matos- Luchi, 627 F.3d at 5. Moreover, Rosero concerned a challenge to jury instructions that allowed the jury to engage in "an unstructured weighing of the totality of the evidence." 42 F.3d at 172. Rosero The version of the MDLEA under which Rosero was decided 15 made the question of whether a vessel was subject to the regulatory jurisdiction of the United States an issue for the jury. 42 F.3d at 171–72. The current version of the MDLEA makes regulatory jurisdiction issues "preliminary questions of law to be determined solely by the trial judge." 46 U.S.C. § 70504(a). - 49 - thus addressed whether a vessel may be deemed "without nationality" under the MDLEA based on jury instructions that invited the jury to consider all the evidence without instructing the jury about what would make a vessel "without nationality." As a result, Rosero did not address whether (as Matos-Luchi reasoned) a vessel is "without nationality" because, insofar as a sustainable claim of nationality cannot be made, the vessel is not authorized to fly the flag of the nation to which it is claimed to belong. The other precedent that the defendants point to is one of our own: United States v. Potes, 880 F.2d 1475 (1st Cir. 1989). But we do not agree with the defendants that Potes holds that, contrary to Matos-Luchi's dicta, a bare claim of nationality in and of itself suffices to demonstrate that a vessel is not a vessel "without nationality" under § 70502(c)(1)(A), even absent the application of a provision like § 70502(d)(1)(C). See Potes, 880 F.2d at 1478-79. Like Rosero, Potes concerned only the earlier version of the MDLEA. It thus addressed the standard for showing that a vessel was "without nationality" beyond a reasonable doubt rather than merely by a preponderance of the evidence. See Matos-Luchi, 627 F.3d at 5. Moreover, while Potes held that the record there did not suffice to support a determination that sufficient proof of the "vessel without nationality" requirement had been provided, the vessel at issue in that case was flying a foreign flag. 880 - 50 - F.2d at 1478. Potes thus does not address whether, per the reasoning in Matos-Luchi, a vessel in circumstances like those presented here may be deemed by a preponderance of the evidence to be "without nationality" under § 70502(c)(1)(A) for reasons independent of the application of § 70502(d)(1)(C). c. Of course, if it were clear or obvious that the Matos- Luchi-based ground for deeming the defendants' vessel to be "without nationality" under § 70502(c)(1)(A) of the MDLEA could not suffice to show that the vessel was also stateless under international law, then the defendants might still prevail in challenging the constitutionality of their convictions under the Felonies Clause. In that event, we would have to address how § 70502(d)(1)(C) fares under the Felonies Clause to determine whether the challenge could succeed. But our review of whether the defendants' vessel is not only "without nationality" for purposes of § 70502(c)(1)(A) under Matos-Luchi but also stateless for purposes of international law under that same precedent is itself only for plain error. After all, in purporting to counter the government's reliance on Matos- Luchi, the defendants are again necessarily challenging the legal import of the factual admissions that they made in their guilty pleas. Yet, the defendants made no argument below that the facts that they admitted to in pleading guilty could not suffice under - 51 - Matos-Luchi to render their vessel stateless under international law. Moreover, Matos-Luchi is clear that its analysis is not limited to the statutory question addressed above about when a vessel is "without nationality" under § 70502(c)(1)(A) of the MDLEA. That analysis also applies to the international law question of when a vessel is stateless. Matos-Luchi, 627 F.3d at 6; see also Rosero, 42 F.3d at 171 (interpreting the predecessor of § 70502(c)(1)(A) to describe vessels that are both "without nationality" as a statutory matter and "stateless under international law"). Thus, here, too, the defendants cannot show that it is clear or obvious that the government's Matos-Luchi- based defense of the convictions -- and thus the government's defense of the convictions on a ground independent of § 70502(d)(1)(C) -- is mistaken. As a result, the Felonies Clause- based challenge fails for that reason alone. d. As a fallback, the defendants contend that they need not show that the government's Matos-Luchi-based theory is clearly or obviously wrong to succeed on the Felonies Clause-based challenge to their convictions, even assuming that the indictment itself is sound. They contend that is so because the government is engaged in impermissible "jurisdiction switching" in relying on the Matos- Luchi theory to defend the convictions on appeal. The defendants - 52 - argue in that contention that § 70502(d)(1)(C) is the only jurisdictional provision on which the government relied below. For that reason, they contend, it is also the only jurisdictional provision that the government may put in play on appeal. The dissent then goes on to contend not only that the defendants are right on this score but also that it follows that the only Felonies Clause-based challenge before us is the defendants' challenge to § 70502(d)(1)(C). And, the dissent proceeds to argue, because the defendants also challenged that provision below under the Felonies Clause in moving to dismiss the indictment, the challenge is preserved, thereby making our review of that challenge on appeal de novo rather than for plain error.16 16In making the claim of "jurisdiction switching," neither the defendants nor the dissent contends that the defendants reasonably but mistakenly thought in pleading guilty that their vessel was being deemed stateless only based on § 70502(d)(1)(C). The defendants and the dissent contend instead only that the plea agreements must be construed to bar the government from arguing that the defendants' vessel is "without nationality" under the MDLEA and stateless under international law on any basis other than § 70502(d)(1)(C). Thus, the aim of the contention is not to explain why the pleas must be vacated for not having been knowingly and voluntarily made, such that we need not resolve whether § 70502(d)(1)(C) comports with the Felonies Clause to overturn the convictions. The aim instead is to show that we must decide whether § 70502(d)(1)(C) comports with that Clause to resolve the defendants' Felonies Clause-based challenge because the government gave up reliance on any other jurisdictional theory. - 53 - For reasons that we will next explain, we do not find this line of argument to be persuasive. And that is so even if we were to excuse its late-breaking nature.17 To start, the only jurisdictional provision of the MDLEA to which the plea agreements refer is § 70502(c)(1)(A), not § 70502(d)(1)(C). Yet that provision "includes" as a ground for a vessel to be "without nationality" the one that is laid out in Matos-Luchi: The person making the oral claim of nationality for the vessel on which the vessel's claim to being foreign depends is not "in a position to provide evidence" of its claimed nationality. 627 F.3d at 6 (quoting Andrew W. Anderson, Jurisdiction over Stateless Vessels on the High Seas: An Appraisal Under Domestic and International Law, 13 J. Mar. L. & Com. 323, 341 (1982)). Moreover, the plea agreements incorporated the Government's Version of the Facts, which included facts concerning the lack of any indicia of nationality aboard the defendants' vessel. Yet those facts are relevant only to the Matos-Luchi- based ground that § 70502(c)(1)(A) includes and not to the 17As we will explain, the defendants raised this concern about "jurisdiction switching" only in their briefing to the en banc court, which they submitted only after the panel majority had sua sponte raised and relied on the ground that the government could not switch jurisdictional theories. See Dávila-Reyes II, 23 F.4th at 164-65. - 54 - § 70502(d)(1)(C)-based ground that the plea agreements do not mention. These features of the plea agreements warrant attention because, although we construe ambiguities in plea agreements in favor of defendants, United States v. Newbert, 504 F.3d 180, 185 (1st Cir. 2007), we are not free to read the plea agreements "ex silentio, to include a waiver by the government," United States v. Anderson, 921 F.2d 335, 338 (1st Cir. 1990). For, "[w]hile the government must be held to the promises it made in a plea agreement, it will not be bound to those it did not make." Id. (cleaned up) (quoting United States v. Fentress, 792 F.2d 461, 464 (4th Cir. 1986)). And, here, the nature of the plea agreements is such that we could find the claimed waiver only by reading them silently to include it. Indeed, with respect to the MDLEA's jurisdictional requirement, the plea agreements mirrored the indictment, which itself referred only to § 70502(c)(1)(A) and alleged no facts that impliedly made it dependent on § 70502(d)(1)(C) alone. Given that even the dissent acknowledges that the indictment cannot be construed to be predicated solely on § 70502(d)(1)(C), we find it hard to see how the government may be understood to have "intentional[ly] relinquished" or "affirmatively disclaimed" reliance on any "jurisdictional" provision other than § 70502(d)(1)(C) merely by having entered into plea agreements - 55 - that reference only the same more encompassing "jurisdictional" provision that the indictment itself did. United States v. Carrasco-De-Jesús, 589 F.3d 22, 26 (1st Cir. 2009). The dissent does make much of the criminal complaint that preceded the indictment. But, like the indictment, the complaint also does not refer to § 70502(d)(1)(C) or to facts that bear only on its applicability. And, ultimately, the dissent itself does not contend that the criminal complaint locked the government into relying on that theory alone. The dissent is right that the defendants chose to "focus[]" on § 70502(d)(1)(C) in their motion to dismiss the indictment. See dissent, infra, at 7. But the defendants obviously cannot narrow the indictment -- and thereby preclude the government from asserting a ground for determining the vessel's nationality that the indictment on its face does not exclude -- merely by choosing to challenge the indictment on a limited ground. So, in the end, the asserted waiver must be found in the government's post-indictment filings. But we cannot agree that in them the government waived any or all grounds for deeming the vessel to be "without nationality" other than the one that § 70502(d)(1)(C) recognizes. The government's brief in opposition to the defendants' motion to dismiss the indictment did cite to § 70502(d)(1)(C). - 56 - But it did so only twice -- and then without at either point identifying that provision as supplying the sole basis for deeming the defendants' vessel stateless. The brief instead referred to that provision in explaining Matos-Luchi's holding that "the MDLEA's definition of a 'vessel without nationality' provided a non-exhaustive list of possible circumstances that would qualify a particular vessel, while acknowledging that customary international law may encompass additional types of vessels" (citing 627 F.3d at 7).18 The paragraph of the government's response to the motion that directly followed that discussion, moreover, set out the same facts that the defendants' plea agreements later included -- that the vessel's master claimed their vessel had Costa Rican nationality, that Costa Rica could not confirm that claim, that the defendants did not present registration paperwork, and that the vessel was devoid of indicia of nationality. And it was only after having recounted all those facts -- the last two of which concern the Matos-Luchi-based predicate rather than the § 70502(d)(1)(C)-based one -- that the government asserted without The brief's other reference to § 70502(d)(1)(C) was made 18 in restating the defendant's contention that that provision was unconstitutionally vague. - 57 - reference to any one jurisdictional theory that "[t]herefore, the vessel was without nationality" (emphasis added). The government thereafter filed a motion of its own in which it requested that the District Court find that the defendants' vessel was "subject to the jurisdiction of the United States." But that filing, too, did not purport at any point to commit the government to relying only on the § 70502(d)(1)(C)- based theory for deeming the defendants' vessel "without nationality" under the MDLEA, regardless of what the indictment charged or the record showed in that regard. True, the motion pointed to facts that would satisfy § 70502(d)(1)(C). But, in support of the conclusion that there was "ample evidence" that the vessel was subject to the jurisdiction of the United States "as defined in Title 46, United States Code, Sections 70502(c)(1)(A) and (d)(1)(C)" (emphasis added), the motion listed facts that bear on the Matos-Luchi-based theory (which itself falls under § 70502(c)(1)(A)) no less than on the § 70502(d)(1)(C)-based one. We therefore do not understand the motion, in requesting that the District Court "find as a matter of law that the vessel in question was subject to the jurisdiction of the United States" on the statutory grounds, to have amounted to a waiver by the government of its right to rely on a Matos- - 58 - Luchi-based ground for so finding insofar as § 70502(c)(1)(A) encompasses that ground. The dissent does contend that the State Department Certification attached to the government's motion to establish jurisdiction locked the government into proceeding on a § 70502(d)(1)(C)-based theory alone. The dissent emphasizes that the certification states that "the Government of the United States determined the vessel was without nationality in accordance with 46 U.S.C. § 70502(d)(1)(C), rendering the vessel subject to the jurisdiction of the United States, pursuant to 46 U.S.C. § 70502(c)(1)(A)." But the certification was only one of the evidentiary attachments to the motion, and in purporting to support the jurisdictional basis provided for in § 70502(d)(1)(C), the certification does not purport to disclaim all others. Indeed, as we have explained, the certification was attached to a motion that itself recited facts elsewhere supported in the record that were relevant not only to the § 70502(d)(1)(C)-based theory but also to the Matos-Luchi-based one. Nor is this a case in which a district court ruling established that the only jurisdictional ground in play was narrower than the grounds encompassed by the indictment and supported by the admitted facts. The defendants pleaded guilty to the charges set forth in the indictment before the District Court - 59 - had passed on the government's jurisdictional motion. And, in doing so, they entered into plea agreements that, like the indictment, conspicuously did not mention -- with respect to whether the vessel was "subject to the jurisdiction of the United States" -- § 70502(d)(1)(C). Instead, the plea agreements mentioned only the facially more encompassing § 70502(c)(1)(A). Finally, it is worth noting that, while the defendants now press the "jurisdiction switching" point to fend off the government's Matos-Luchi-based defense of the convictions, the defendants did not make this point in their oral argument to the panel, where the Matos-Luchi theory was raised, nor did they raise it in their supplemental briefing to the panel. And that is so even though the defendants submitted their supplemental brief after the government had advanced the Matos-Luchi-based theory for deeming their vessel "without nationality" in its own supplemental brief. If indeed the parties to the plea agreements had agreed that the government precluded itself from relying on a theory of jurisdiction supported by the admitted facts, one would have expected the defendants themselves -- rather than judges who were not party to the agreement -- to have been the ones to raise that interpretation of the agreements. In fact, the defendants chose at that time to take on the merits of the theory without asserting any waiver. And, they argued, too, that in pleading guilty they were not making any - 60 - admissions at all regarding the legal basis for deeming their vessel "without nationality" under the MDLEA precisely because that question was reserved to the District Court by § 70504(a) of the MDLEA. As the defendants put it, "the guilty plea conceding factual guilt does not resolve the antecedent question of the [United States'] ability to assert jurisdiction over appellants' vessel." Thus, it was only in the panel opinion -- and not in any filing that the defendants themselves had made up to that point -- that the notion first appeared of the government having agreed in the plea agreements to be barred from relying on a Matos- Luchi-based theory to defend the convictions even if the indictment encompassed it and the record supported it. See Dávila-Reyes II, 23 F.4th at 164-65. So, while the dissent contends that our conclusion that the Matos-Luchi theory of jurisdiction remained available to the government after the plea agreements were struck is "patently absurd," the dissent does not dispute that the contention originated with the panel rather than the defendants themselves. It would thus appear that what the dissent contends is self-evident about the plea agreements was not self-evident to the actual parties to those plea agreements. In our view, then, if a gloss is being retroactively imposed on the record, it is the gloss that would attribute to the government an intentional waiver of the Matos-Luchi-based theory. But, as no authority establishes - 61 - that the government must be understood in these circumstances to have intentionally (though silently) made such a waiver, cf. Caraballo–Rodriguez, 480 F.3d at 75 (explaining that "a novel interpretation of the [relevant] statute" advanced by the government in response to a challenge to the factual basis of a plea "cannot be said to be plainly erroneous" even when the court had "found no . . . cases discussing the theory"), we cannot accept the contention that one was made. B. Having explained that the defendants' Felonies Clause- based claim fails in all its variants, we move on to the defendants' remaining claims. The first of those claims is that the indictment does not charge a crime that comports with the Due Process Clause because a key aspect of § 70502(d)(1)(A) and § 70502(d)(1)(C) is void for vagueness. But here, again, we are not persuaded that there is any basis for concluding, even on de novo review, that the indictment is dependent on the application of § 70502(d)(1)(C) in alleging that the defendants violated the MDLEA while aboard a vessel "without nationality" under § 70502(c)(1)(A). And, as we have explained, there is no basis on plain error review for concluding that the record at the time of the judgments of conviction was such that § 70502(d)(1)(C) provided the sole means of determining the defendants' vessel to have been "without nationality." Nor, - 62 - as we also have explained, can we conclude that the government waived the Matos-Luchi-based theory that it advances in defending the convictions. Thus, we must reject this constitutional claim because it rests on the unfounded premise that § 70502(d)(1)(C) supplies the sole basis for deeming the defendants' vessel to be "without nationality" under § 70502(c)(1)(A). We add only that, because the defendants at no point developed an argument below or to us as to how § 70502(d)(1)(A) might apply to their case, we must reject this challenge as it relates to that provision as well. C. We next must address the defendants' claim under the Due Process Clause in which they target a supposed failure by the government to establish any nexus between the defendants' allegedly unlawful conduct and the United States. The defendants have developed this challenge only insofar as they contend that they were aboard a vessel with foreign nationality. They have not developed any argument as to why there must be such a nexus even if the vessel was stateless under international law. As we have explained, however, we cannot conclude, even on de novo review, that the indictment charged the defendants with being on a vessel that could be deemed "subject to the jurisdiction of the United States" only on grounds that would fail to show that the vessel was stateless under international law. And, as we have also explained, there is no basis, on plain error review, for - 63 - concluding that the record as it stood at the time of the defendants' convictions only supports a ground for deeming their vessel to have been "subject to the jurisdiction of the United States" that clearly or obviously would not suffice to permit the vessel to be deemed stateless under international law. Finally, for the reasons given above, the government may not be understood to have waived all jurisdictional theories save for the one based on § 70502(d)(1)(C). Thus, this constitutional claim fails, too. D. There remains only to address the defendants' claim that the government violated the Due Process Clause by failing to bear the burden of showing that the defendants' vessel was stateless under international law. But, as best we can tell, the premise for this claim is that the sole basis for deeming the vessel to be "without nationality" under § 70502(c)(1)(A) is by operation of § 70502(d)(1). Thus, this constitutional claim fails for the same reasons that the other claims we have addressed fail -- it rests on a premise that cannot be sustained as to the indictment, even on de novo review, or as to the record at the time of the judgments of conviction, under plain error review, and the government did - 64 - not intentionally relinquish reliance on all jurisdictional theories save for the one based on § 70502(d)(1)(C).19 V. For the reasons given above, the judgments of the District Court are affirmed. -Dissenting Opinion Follows- 19We note that we must also reject the defendants' sole, purely statutory challenge -- that the government improperly relied on § 70502(d)(1)(C) to establish that their vessel was "without nationality" because § 70502(d)(1)(C) references only a claim of "registry" and defendants made a claim of nationality. The reason is by now familiar. The defendants cannot show, even on de novo review, that the indictment is premised solely on § 70502(d)(1)(C), and they cannot show, on plain error review, that it is clear or obvious from the state of the record at the time that the defendants entered their guilty pleas that § 70502(d)(1)(C) provided the sole basis for deeming the vessel "without nationality." Nor can the defendants show that the government waived all "jurisdictional" theories other than the § 70502(d)(1)(C)-based one. - 65 - LIPEZ, THOMPSON, and MONTECALVO, Circuit Judges, dissenting. It is a basic principle of plea agreements, derived from contract law, that the parties' written agreement embodies their commitments to each other and governs their expectations. Today, in their effort to avoid important and complex issues concerning the United States' authority to prosecute foreign nationals encountered on vessels in international waters, our colleagues in the majority have done serious damage to the reliability of plea agreements. Stymied by the content of appellants' agreements and the proceedings leading to their pleas, the majority adopts a view of the record inappropriately favorable to the government and justifies the analysis with an indefensible application of the plain-error doctrine. We cannot accept the resulting perversion of the plea process and, for that reason among others, dissent from the majority's decision. I. Using the majority's terminology, we wish to make clear that our disagreement with our colleagues' analysis does not arise from their treatment of the so-called "first variant" of appellants' constitutional claim, a dichotomy imposed by the majority. We recognize that the indictment itself does not specify the basis on which the government was alleging that the defendants were on board a vessel without nationality. Nor are we saying that the criminal complaint that initiated appellants' prosecution - 66 - necessarily fixed the boundaries for the indictment and confined the government to showing that appellants' vessel was stateless pursuant to 46 U.S.C. § 70502(d)(1)(C). However, we are saying that when the government reduces the broad terms of an indictment to a specific theory of prosecution and relies on that theory to obtain guilty pleas, the government cannot later justify those convictions with a different rationale when it discovers that its chosen theory is flawed. The majority's "second variant" analysis, however, endorses just such an unfair substitution. As we shall describe, appellants had no reason in the district court proceedings to challenge any basis for deeming their vessel "without nationality" other than by operation of § 70502(d)(1)(C). The majority nonetheless latches onto the omission of any such challenge to avoid appellants' claim that their convictions violate the Felonies Clause because Congress lacked authority to deem their vessel without nationality based on that provision. In other words, the majority addresses appellants' challenge to their convictions under the false pretense that, at the time appellants signed plea agreements, the government was relying on alternative theories for deeming their vessel stateless. Put even more bluntly, the majority performs a sleight- of-hand to allow the government to ambush appellants with a theory of jurisdiction under the Maritime Drug Law Enforcement Act - 67 - ("MDLEA") that was not the one used to secure their guilty pleas. As set forth in detail in Section II below, the government consistently premised its assertion that appellants' vessel was stateless solely on the failure of Costa Rica to "affirmatively and unequivocally" confirm nationality pursuant to 46 U.S.C. § 70502(d)(1)(C). Appellants, in turn, consistently argued that § 70502(d)(1)(C) is unconstitutional and in conflict with international law. That same claim of constitutional invalidity is at the forefront of this appeal from appellants' convictions. Now, the government insists that we should uphold the prosecution, regardless of the validity of § 70502(d)(1)(C), because the facts included in appellants' plea agreements establish that their vessel was "without nationality" apart from § 70502(d)(1)(C). The government thus asks us to treat the litigation history and appellants' reasonable understanding of their plea agreements as irrelevant. The majority condones that strategy and dwells on one alternative theory in particular: that Reyes-Valdivia's oral claim of Costa Rican nationality when confronted on his vessel was ineffective because it was not substantiated by other indicia of nationality. Indefensibly, however, the majority contrives a procedural default that does not exist. The government never changed course in its theory of the prosecution from the time of the criminal complaint through the entry of appellants' guilty - 68 - pleas; it invoked § 70502(d)(1)(C), implicitly or explicitly, at every stage. Nor did any facts change during the course of the proceedings. The affidavit attached to the Criminal Complaint that preceded the indictment contained a "Summary of the Investigation" that included the following information: The master claimed Costa Rican nationality for the vessel but provided no registration paperwork. The Boarding Team reported no further indicia of nationality. The government of Costa Rica was approached to either confirm or deny vessel registry. Costa Rica responded that it could not confirm nor refute the registry of the suspect vessel. The vessel was determined to be one without nationality. Affidavit in Support of Criminal Complaint, United States v. Reyes- Valdivia, No. 3:15-cr-00721-FAB (D.P.R. Nov. 9, 2015), ECF No. 1- 1, at 3-4.20 These facts, which also appear in the plea agreements, give rise to jurisdiction under § 70502(d)(1)(C).21 The government recited these same facts repeatedly throughout the subsequent proceedings to support jurisdiction under § 70502(d)(1)(C). See infra Section II. There was simply no new argument that appellants All subsequent citations in this opinion to the district 20 court's docket will use the short-form "Reyes-Valdivia, ECF No. __ (filing date)." 21Section 70502(d)(1)(C) defines a "vessel without nationality" to include any vessel "aboard which the master or individual in charge makes a claim of registry and for which the claimed nation of registry does not affirmatively and unequivocally assert that the vessel is of its nationality." 46 U.S.C. § 70502(d)(1)(C). - 69 - failed to make, and the majority's plain-error analysis thus depends on altering the assumptions underlying the plea agreements, contrary to basic principles of plea bargaining and contract law. Of course, the majority's ability to rely on plain error is essential to the decision to affirm appellants' convictions without addressing their constitutional challenge to § 70502(d)(1)(C). That is so because the majority relies primarily on dicta contained in a single decision of a divided panel of our court -- which in turn cited only a single authority -- for the proposition that Reyes-Valdivia's oral claim of nationality was inadequate on its own to establish that appellants' vessel was not stateless. See United States v. Matos-Luchi, 627 F.3d 1, 5 (1st Cir. 2010). The adequacy of an oral claim of nationality under international law is one of the issues at the heart of the merits of this case -- relevant to the constitutionality of § 70502(d)(1)(C) -- and a subject the majority desperately wants to avoid. See United States v. Dávila-Reyes (Dávila-Reyes II), 23 F.4th 153, 187-93 (1st Cir. 2022). Only plain-error review allows the majority to give Matos-Luchi's dicta dispositive effect without considering its correctness and, hence, to avoid dealing with the difficult constitutional questions posed by this appeal. It is no surprise that, to establish MDLEA jurisdiction, the government chose to rely on the government of Costa Rica's - 70 - statement that it could neither confirm nor refute Reyes- Valdivia's claim of nationality -- a straightforward method under the MDLEA for deeming a vessel stateless. Now what the government wants us to do, and what the majority has agreed to do, is to uphold the convictions based on a different rationale anchored only in the dicta from Matos-Luchi. That retroactive change-of- course is unfair to appellants and harmful to the plea-bargaining process. II. The en banc majority's analysis rests on the view that the government never relinquished any theory for deeming appellants' vessel "without nationality" that could be supported by the facts incorporated into appellants' plea agreements. Brushing aside the well-established law that ambiguities in plea agreements must be construed in favor of defendants, see infra, the majority instead credits the government with silently preserving a theory of jurisdiction appellants had no reason to contemplate during the plea-bargaining process -- thereby condoning the government's introduction of a new construction of the plea agreements. In fact, a fair reading of the record shows that, from the outset of appellants' prosecutions, and consistently throughout, the government relied exclusively on 46 U.S.C. § 70502(d)(1)(C) to support jurisdiction over appellants and their - 71 - vessel. As recounted above, that approach was previewed in the affidavit attached to the Criminal Complaint, which stated that the "vessel was determined to be one without nationality" after the master claimed Costa Rican nationality and that "Costa Rica responded that it could not confirm nor refute the registry of the suspect vessel." Reyes-Valdivia, ECF No. 1-1, at 3-4. Although -- as we have acknowledged -- the theory of statelessness reflected in the pre-indictment affidavit did not prevent the government from developing other jurisdictional rationales post-indictment, the government's version of the facts and theory of jurisdiction did not change. Each time the government defended the jurisdictional foundation for the prosecution -- in its response to appellants' motion to dismiss the indictment (dated Feb. 16, 2016), in its own motion in support of jurisdiction (dated Mar. 25, 2016), at the change-of-plea hearing (held on Apr. 4, 2016), and in the plea agreements themselves (filed on Apr. 4, 2016) -- the government presented the same facts originally set forth in the Criminal Complaint (filed in Nov. 2015) and never stated that it was proceeding on alternative theories of jurisdiction, one statutory and one non-statutory. Appellants focused on § 70502(d)(1)(C) in their motion to dismiss the indictment. In that motion, after noting that the MDLEA prohibits drug activity by individuals on a vessel subject to U.S. jurisdiction, appellants stated: "As - 72 - relevant here, a 'vessel subject to the jurisdiction of the United States' includes . . . 'a vessel aboard which the master or individual in charge makes a claim of registry and for which the claimed nation of registry does not affirmatively and unequivocally assert that the vessel is of its nationality.' [46 U.S.C.] § 70502(c)(1)(A), (d)(1)(C)." Reyes-Valdivia, ECF No. 29, at 3 (Feb. 1, 2016) (emphasis added). In its response, the government did not contest appellants' assumption that the "relevant" provision was § 70502(d)(1)(C). The response addressed appellants' multiple statutory-based arguments by asserting, inter alia, that the MDLEA is within Congress's authority under the Constitution; that "drug trafficking, as criminalized by the MDLEA, is properly within the scope of the Felonies Clause"; that the MDLEA does not require a nexus between the drug activity and the United States; that the MDLEA is consistent with international law; and that § 70502(d)(1) is not unconstitutionally vague. See Reyes-Valdivia, ECF No. 38, at 3-8, 11-13 (Feb. 16, 2016). The government also noted the applicability of the protective principle of international law. See id. at 17. The government repeated, nearly verbatim, the facts that had appeared in the Criminal Complaint: In this case, the Defendants made a claim of Costa Rican nationality over the vessel. The United States approached the government of Costa Rica and they responded that they could not confirm or deny the nationality of the - 73 - vessel. Furthermore, the Defendants failed to present any registration paperwork supporting their claim and there were no other indicators of nationality, such as a flag, on the vessel. Therefore, the vessel was without nationality. Id. at 11. Although the response cited Matos-Luchi seven times, none of those references invoked the dicta on the need to substantiate an oral claim of nationality. See id. at 8, 11, 12, 15, 16. Indeed, the government distinguished appellants' case from one cited by appellants in which "the [g]overnment [had] attempted to proceed on two theories of jurisdiction" and had "failed to provide any evidence that . . . the alleged flagging nation" had denied the claim of registry. Id. at 16 (discussing United States v. Potes, 880 F.2d 1475 (1st Cir. 1989)). The government asserted that, by contrast, in this case it "ha[d] been consistent in its theory of jurisdiction and provided all [d]efendants in discovery statements by the boarding team and pilots that prove the master's claim of Costa Rican nationality, the lack of other indicia of nationality, and the fact that the U.S. Coast Guard Seventh District Commander permitted the vessel to be treated as one without nationality." Id. The government, in other words, emphasized that it had provided appellants with the facts, first reported in the Criminal Complaint and now reproduced in their response to the motion to dismiss, that appellants understood as premising jurisdiction solely on - 74 - § 70502(d)(1)(C) -- an understanding the government did not dispute in its response to the motion to dismiss. But even if the government's response left ambiguity in its theory of jurisdiction, any lack of clarity was dispelled when the government later filed its motion in support of jurisdiction. The connection between the government's consistently reported facts and § 70502(d)(1)(C) was drawn explicitly in the Department of State Certification that was submitted as an attachment to the government's motion. The Certification, signed by a U.S. Coast Guard Commander, reported that the master of the vessel "made a claim of Costa Rican nationality," that the United States government "requested that the [g]overnment of the Republic of Costa Rica confirm the registry or nationality of the suspect vessel," and that "the [g]overnment of the Republic of Costa Rica replied that it could not confirm [the] vessel's registry." Reyes- Valdivia, ECF No. 46-2, at 1 (Mar. 25, 2016). The Certification then expressly linked those facts to the assertion of jurisdiction: "Accordingly, the [g]overnment of the United States determined the vessel was without nationality in accordance with 46 U.S.C. § 70502(d)(1)(C), rendering the vessel subject to the jurisdiction of the United States, pursuant to 46 U.S.C. § 70502(c)(1)(A)." Id. (emphases added). Significantly, this motion, with its attached Certification, also gives important context for the government's earlier reference, in its response to appellants' - 75 - motion to dismiss, to "the fact that the U.S. Coast Guard Seventh District Commander permitted the vessel to be treated as one without nationality." Reyes-Valdivia, ECF No. 38, at 16. The Certification specifies that the U.S. Coast Guard Commander gave that permission "in accordance with 46 U.S.C. § 70502(d)(1)(C)." The Certification language also reveals a significant flaw in the government's attempt to obscure its chosen theory of jurisdiction by insisting that it always relied on § 70502(c)(1)(A) separately from § 70502(d)(1)(C), thereby giving notice that it was contemplating other rationales for deeming the vessel "without nationality." Section 70502(c)(1)(A) of the MDLEA states generally that "a vessel without nationality" is "subject to the jurisdiction of the United States." 46 U.S.C. § 70502(c)(1)(A). Section 70502(d)(1)(C) specifies one way in which the United States may deem a "vessel without nationality" -- namely, if the master "makes a claim of registry and for which the claimed nation of registry does not affirmatively and unequivocally assert that the vessel is of its nationality." 46 U.S.C. § 70502(d)(1)(C). These two provisions plainly operate in tandem when cited together, as the government consistently did in this case. And, when those provisions were combined with the facts offered by the government, the general allegations of the indictment concerning jurisdiction -- that appellants' vessel was "subject to the jurisdiction of the United States" because it was - 76 - "without nationality" -- were reduced to the specific version of the crime the government was charging. The Certification sets forth that specific theory in unambiguous terms: appellants' boat was subject to United States jurisdiction as a "vessel without nationality" under § 70502(c)(1)(A) because the circumstances satisfied the requirements of § 70502(d)(1)(C).22 As noted above, the government had emphasized in its response to appellants' motion to dismiss that it "ha[d] been consistent in its theory of jurisdiction," thus giving appellants no reason to believe that it was invoking any theory of statelessness other than § 70502(d)(1)(C). Put simply, the unmistakable import of the government's representations in the district court is that the government relied consistently -- and exclusively -- on the theory of statelessness that appellants have consistently challenged. The government attempts to step away from that acknowledgment by pointing out that it had no opportunity to press 22As the panel majority opinion explained, it does not matter that § 70502(d)(1)(C) by its terms applies when there has been a "claim of registry" but, in this case, Reyes-Valdivia made a claim of Costa Rican nationality. See Dávila-Reyes II, 23 F.4th at 165- 69. Both the government and appellants assumed that § 70502(d)(1)(C) applied to Reyes-Valdivia's claim of nationality until the panel suggested otherwise in a request for supplemental briefing. Whether § 70502(d)(1)(C) covers claims of nationality is a distinct question from whether, in the particular circumstances of this case, that provision was the basis on which the government asserted MDLEA jurisdiction. - 77 - other theories of statelessness because appellants pleaded guilty before the district court ruled on its motion in support of jurisdiction. Nowhere in that motion, however, does the government indicate that it was planning to argue that the vessel could be deemed "without nationality" on the ground that appellants did not substantiate Reyes-Valdivia's oral assertion of Costa Rican nationality with documentary or visual indicia of nationality. There is no reference in the motion to the Matos-Luchi dicta on which the majority relies. Indeed, as described above, the motion included the Certification as an attachment and, referring to the Certification's contents, the government asserted that the Coast Guard Commander "certified that the Government of Costa Rica was approached and could neither confirm nor deny registry of the go- fast vessel, thereby enabling the United States to treat the vessel as one without nationality pursuant to Section 70502(d)[(1)](C)." Reyes-Valdivia, ECF No. 46, at 4 (emphasis added). It is clear from this motion -- filed a week before appellants moved to change their pleas -- that the government was adhering to its "consistent" reliance on § 70502(d)(1)(C). Critical, of course, is what admissions appellants understood they were making at the time they signed their plea agreements. We have recognized that, in construing plea agreements, "[t]he touchstone is the 'defendant's reasonable understanding.'" United States v. Gardner, 5 F.4th 110, 114 (1st - 78 - Cir. 2021) (quoting United States v. Conway, 81 F.3d 15, 17 (1st Cir. 1996)); see generally United States v. Gall, 829 F.3d 64, 72 n.6 (1st Cir. 2016) (citing cases for the general proposition that a court's construction of a plea agreement should align with the reasonable expectations of the parties). If there is any uncertainty about the scope of defendants' pleas, the consequence of the imprecision "must fall upon the government," United States v. Newbert, 504 F.3d 180, 185 (1st Cir. 2007), "not only because ambiguities in contracts are traditionally interpreted against the drafter, but also because plea agreements implicate broader societal interests, some of constitutional magnitude," id. at 185 n.3 (citation omitted). At the change-of-plea hearing, when asked to "give a brief explanation of the theory to be presented to prove each Defendant guilty if a trial were to be held," the prosecutor stated, in relevant part: The vessel was tracked by aircraft and eventually came to a stop. The U.S. Coast Guard boarding team approached the vessel and commenced right of approach questioning. The master claimed Costa Rican nationality for the vessel but provided no registration[] paperwork, and there was no indicia of nationality on the vessel. The Government of Costa Rica was approached. They responded they could neither confirm nor refute the registry of [the] suspect vessel. The vessel was determined to be one without nationality. - 79 - Reyes-Valdivia, ECF No. 117, at 25-26 (Oct. 3, 2016). These same facts -- reiterating Reyes-Valdivia's claim of nationality and Costa Rica's failure to confirm or deny his claim -- were incorporated into the plea agreements themselves. Hence, a reasonable defendant would conclude that the plea agreements' inclusion of the same facts used consistently by the government to support jurisdiction based solely on § 70502(d)(1)(C) meant that the government was relying solely on that provision as the jurisdictional foundation for their guilty pleas. It is not reasonable to attribute to appellants an awareness of a different theory of statelessness that they also needed to challenge. Given the government's handling of the case from inception to pleas, the majority's resort to plain-error review of a different jurisdictional rationale is unfathomable.23 The majority makes much of the fact that the government's version of the relevant events includes information that is not part of the § 70502(d)(1)(C) requirements, specifically that the vessel had no registration paperwork or other indicia of Costa The government also makes a somewhat different plain-error 23 argument in its en banc briefing, asserting that appellants failed to argue that their guilty pleas lacked a factual foundation. However, putting aside the statutory-language problem first noted by the panel, see supra, Reyes-Valdivia and Dávila-Reyes have not contested that the facts stated by the government satisfy the requirements of § 70502(d)(1)(C) and thus provide a statutory foundation for their guilty pleas. Their claim challenges the authority of the government to rely on § 70502(d)(1)(C). - 80 - Rican nationality on board. However, the government's report that no evidence of nationality was found on the vessel -- in the same sentence reporting the master's oral claim of nationality -- does not indicate, or even suggest, that the government was setting forth a theory of jurisdiction independent of § 70502(d)(1)(C). The factual statement does not declare that the vessel was determined to be without nationality because no corroborating evidence was found. Nor does the government preface the report of its inquiry to Costa Rica with language -- such as "In addition" -- to indicate that § 70502(d)(1)(C) was a second, independent basis for deeming the vessel "without nationality." Rather, the sequence of facts in the statement confirms that the vessel was determined to be without nationality, per the Certification, "in accordance with 46 U.S.C. § 70502(d)(1)(C)." The majority's use of the government's reference to the lack of corroboration to infer an unarticulated alternative theory of statelessness is thus unjustified from a commonsense reading of the factual statement. That approach is especially unacceptable given our obligation to impose the burden of any ambiguity in plea agreements on the government. Absent some explicitly stated connection between those non-essential facts and a non-statutory theory of jurisdiction, the inclusion in the plea agreements of the same facts that had informed every phase of the prosecution simply does not show -- or even suggest -- that the government is - 81 - relying on any basis other than § 70502(d)(1)(C) to deem appellants' vessel without nationality. We do not know why the government placed those facts in the plea agreements. Perhaps the government wanted to eliminate any possibility that appellants could reassert their earlier claim that the vessel bore indicia of nationality.24 What we do know, however, is that the government did not communicate a connection between those facts and the non- statutory theory of statelessness attributable to the dicta in Matos-Luchi. There is not even a hint in the provisions of the plea agreements that the government was relying on multiple theories of jurisdiction. It is irrelevant that the agreements do not expressly cite to § 70502(d)(1)(C). As explained above, the unelaborated reference in the agreements to § 70502(c)(1)(A) serves to identify the pertinent category of vessels "subject to United States jurisdiction" -- i.e., vessels "without nationality" 24 Appellants argued to us that "[p]hotos of the vessel clearly show the civil ensign of Costa Rica painted, albeit vertically, on the port and starboard sides of the ship's bow." See Dávila-Reyes II, 23 F.4th at 164 n.20 (quoting Appellants' Supp. Br. at 18 n.4). That assertion is supported by a statement attached as an exhibit to the government's motion in support of jurisdiction, in which a U.S. Customs Boarding Officer reported that a marine patrol had spotted a vessel "with a Costa Rican flag painted on the bow." Id. As the panel majority observed, however, appellants necessarily gave up the claim that their vessel bore indicia of Costa Rican nationality when they pled guilty based on the "Government's Version of the Facts" incorporated into their plea agreements. Id. - 82 - -- but it does not identify the specific basis on which appellants' vessel fit within that category. Id. It is the factual statement incorporated into the plea agreements, detailing the government's compliance with § 70502(d)(1)(C) in the same way the government had been doing throughout the proceedings, that provides the necessary, specific basis for that finding. There is simply no room for debate about the theory of jurisdiction on which the plea agreements -- and thus the guilty pleas -- rested. On appeal, too, the government maintained its focus on § 70502(d)(1)(C). See Dávila-Reyes II, 23 F.4th at 163 n.18. Its appellate brief linked § 70502(c)(1)(A) and § 70502(d)(1)(C) in the way we have emphasized -- i.e., citing them as a single invocation of jurisdiction -- when it stated: "The absence of an assertion by the Costa Rican government rendered the Appellants' boat a 'vessel without nationality,' [46 U.S.C.] § 70502(d)(1), and thus a 'vessel subject to the jurisdiction of the United States,' id. § 70502(c)(1)(A)." Id. (alteration in original) (emphases added). This framing again clearly reveals the government's view that appellants' vessel was subject to United States jurisdiction because the circumstances matched one of the definitions of a stateless vessel listed in § 70502(d)(1). In its supplemental en banc brief, the government argues at length that the examples of vessels without nationality listed in § 70502(d)(1)(A)-(C) are "non-exhaustive" and that the - 83 - government can establish that a vessel is "without nationality" in various ways.25 The government asserts that, if appellants had not pleaded guilty, it "would have been prepared" to prove that the vessel both fell within § 70502(d)(1)(C) and "otherwise qualified as a stateless vessel under international law." But the question here is not what theory the government could have used; the question is what rationale it did use to secure the guilty pleas.26 Notably, even in its motion on jurisdiction, when the government was required to make clear to the court the jurisdictional basis for the prosecution, the government 25In December 2022, a fourth type of vessel was added to the list in § 70502(d)(1): "a vessel aboard which no individual . . . claims to be the master or is identified as the individual in charge, and that has no other claim of nationality or registry under paragraph (1) or (2) of subsection (e)." 46 U.S.C. § 70502(d)(1)(D). The pertinent paragraphs of subsection (e) refer to documents "evidencing the vessel's nationality" and "flying [a] nation's ensign or flag." Id. § 70502(e)(1), (2). 26 Unsurprisingly, the government's assertion that it could have demonstrated that appellants' vessel "otherwise qualified" as "without nationality" relies, in part, on a report that Reyes- Valdivia initially told a Coast Guard Boarding Officer that appellants' vessel had no nationality. In other words, the government highlights that Reyes-Valdivia had admitted a fact that would be decisive in establishing that the vessel was "without nationality" apart from the requirements of § 70502(d)(1)(C). But that fact was not in the Criminal Complaint or the Department of State's official attestation of jurisdiction. And, critically, it was not in the government's recitation of facts at appellants' change of plea hearing, in the "Government's Version of the Facts" incorporated into their plea agreements, or in appellants' Presentence Investigation Reports. As the majority also recognizes, at least implicitly, the government cannot now retrieve a fact it plainly chose to abandon. - 84 - ultimately and only asked the district court to make a finding and instruct the jury "pursuant to Title 46, United States Code, Section 70502(c)(1)(A) and (d)(1)(C) that the suspect vessel carrying the Defendants was a vessel Without Nationality and therefore subject to the jurisdiction of the United States." Reyes-Valdivia, ECF No. 46, at 5 (emphasis added). There was no alternative request for the court to instruct the jury or make a finding of jurisdiction under general principles of international law based on the lack of corroboration of Reyes-Valdivia's oral claim. Given the definitive pronouncements by the government seeking court validation of § 70502(d)(1)(C) as the basis for its assertion of jurisdiction over the vessel, it is absurd for the majority to validate the government's contention that it was proceeding under alternative theories. And it is simply preposterous to say that appellants should have understood that their plea agreements left the door open to theories of statelessness other than § 70502(d)(1)(C). Indeed, the majority's view of the record depends on drawing meaning from what the government did not say. In effect, the majority holds that, because the government did not promise to rely only on § 70502(d)(1)(C), any theory of jurisdiction that could be supported by the facts in appellants' plea agreements remained on the table -- regardless of whether the government had specifically invoked such alternatives during the proceedings that - 85 - culminated with appellants' guilty pleas. As we have described, the government never told appellants or the district court that it was relying on the Matos-Luchi dicta as a basis for jurisdiction over appellants' vessel, while it repeatedly relied expressly on § 70502(d)(1)(C). For the majority, the government's singular reliance on that statutory provision does not matter. Our colleagues, for example, discount the State Department's certification that appellants' vessel was determined to be without nationality "in accordance with 46 U.S.C. § 70502(d)(1)(C)" by observing that "the certification does not purport to disclaim all other[]" theories of jurisdiction. In other words, the government may retroactively introduce the non-statutory Matos-Luchi rationale because it never promised not to do so. We cannot emphasize enough that the question at this juncture is not what theories the government could have offered to support jurisdiction, but what theory informed appellants' decision to plead guilty. As should be clear by now, the plea agreements incorporated the facts consistently cited by the government to establish that appellants' vessel was "without nationality" pursuant to § 70502(d)(1)(C): the claim of nationality and the failure of Costa Rica to "affirmatively and unequivocally" confirm nationality. That theory of jurisdiction, and that theory alone, should determine the validity of appellants' convictions. - 86 - III. The majority acknowledges that appellants argued in their motion to dismiss the indictment that the government had deemed their vessel to be "without nationality" based solely, and unconstitutionally, on § 70502(d)(1)(C).27 Our colleagues thus realize that they cannot say that appellants failed to preserve the argument that their convictions must be vacated because § 70502(d)(1)(C) is unconstitutional. Hence, needing to find a rationale for the application of plain error, the majority contends that appellants failed to timely argue against theories for deeming their vessel stateless that are not based on § 70502(d)(1)(C). And, because the government's oft-repeated version of the facts supports a determination of statelessness pursuant to the dicta in Matos-Luchi, the majority concludes that there is no clear or obvious error and that appellants' convictions are properly affirmed. This contrived use of plain error -- i.e., the disregard of the government's singular reliance on § 70502(d)(1)(C) -- is The majority notes that appellants argued that "[a] vessel 27 may not be deemed stateless under international law . . . simply because the nation to which the vessel's master has claimed that it belongs fails to 'affirmatively and unequivocally assert,' § 70502(d)(1)(C), that the vessel is registered with that nation." The majority further observes that appellants construed the indictment to "charge[] that the vessel that the defendants were aboard was 'without nationality' under § 70502(c)(1)(A) solely based on the operation of § 70502(d)(1)(C)." (Emphasis added.) - 87 - contrary to our obligation to "hold prosecutors . . . to 'the most meticulous standards of both promise and performance'" in effectuating a plea agreement. United States v. Lessard, 35 F.4th 37, 42 (1st Cir. 2022) (quoting United States v. Clark, 55 F.3d 9, 12 (1st Cir. 1995)). As we indicated above, our colleagues' reasoning permits the government to retroactively expand the jurisdictional foundation for appellants' guilty pleas. That is not the way ordinary contracts work, and it is the principles of contract law that govern plea agreements. See generally Garza v. Idaho, 139 S. Ct. 738, 744 (2019) ("[P]lea bargains are essentially contracts." (quoting Puckett v. United States, 556 U.S. 129, 137 (2009))); see also United States v. Brown, 31 F.4th 39, 50 (1st Cir. 2022) ("Traditional principles of contract law guide our interpretation of the terms and performance of a plea agreement."). We find especially troubling the unilateral revision of a contractual agreement when the result is to disfavor the party who gave up "a panoply of constitutional rights." United States v. Tanco-Pizarro, 873 F.3d 61, 65 (1st Cir. 2017) (quoting United States v. Almonte-Nunez, 771 F.3d 84, 89 (1st Cir. 2014)). As we have demonstrated, at the time they negotiated and signed their plea agreements, appellants had no reason to evaluate whether to plead guilty based on theories of MDLEA jurisdiction other than § 70502(d)(1)(C). The facts giving rise to jurisdiction under that provision were undisputed. But there were factual and - 88 - legal issues relevant to the Matos-Luchi dicta on which the majority relies to affirm appellants' convictions. Indeed, appellants gave up the contention that their vessel bore indicia of nationality when they signed plea agreements that included the fact that the vessel lacked any such display. See supra note 24. If the government was not relying solely on jurisdiction under § 70502(d)(1)(C), surely appellants were entitled to explicit notice of such other theory or theories before agreeing to give up competing facts and arguments, and ultimately pleading guilty. To justify appellants' prosecutions based on jurisdictional theories unspecified when they agreed to admit guilt is not only unfair in this case but also troubling as a precedent for plea agreements more generally. If the government is permitted to support convictions by superimposing a new rationale on plea agreements that were so clearly premised on different understandings, the concept of plea agreements as contracts -- whose linchpin is the reasonable expectations of the parties -- will be grievously eroded. The government made its choice to rely on § 70502(d)(1)(C) when it obtained appellants' acquiescence to facts the government had consistently invoked to deem their vessel "without nationality" under that specific provision. The panel majority concluded that the government's chosen theory is unconstitutional. Hence, in effect, the en banc majority is - 89 - holding that the government may unilaterally renegotiate the deal it struck with a defendant when flaws are identified in the original agreement. The majority's approach is not restricted to proceedings under the MDLEA and thus could be used to the government's advantage whenever it chooses. The harm to the plea- bargaining process from the majority's holding is severe and indefensible. As described above, however, the majority maintains that appellants should have realized that the facts in the plea agreements, along with citation to the MDLEA provision that generally authorizes jurisdiction over vessels "without nationality," preserved jurisdictional theories that the government never specifically invoked. In other words, according to the majority, appellants should have challenged theories on which the government did not rely because the government never pledged to forego reliance on them at a later juncture. To bolster their position that plain error thus applies to the Matos-Luchi- based theory, our colleagues repeatedly and pointedly say that the claim of "jurisdiction switching" -- their term -- was voiced by appellants "only in their briefing to the en banc court, which they submitted only after the panel majority had raised and relied on the theory sua sponte." Hence, our colleagues say, "if a gloss is being retroactively imposed on the record, it is the gloss that - 90 - would attribute to the government an intentional waiver of the Matos-Luchi-based theory." But we are not arguing that the government waived reliance on Matos-Luchi. Rather, the government is precluded from switching jurisdictional gears because of ordinary contract principles and the particular importance of adhering to those principles in the context of plea-bargaining. As explained above, appellants have focused on the validity of their prosecutions based on § 70502(d)(1)(C) because that was the sole jurisdictional rationale specifically relied upon by the government throughout the proceedings in the district court. The panel majority's statement that the government could not reconceive the plea agreements retroactively was -- and is -- merely an inescapable conclusion based on contract law and our obligation to honor a defendant's reasonable understanding of his plea agreement. Even if appellants in their en banc briefs had not repeated the panel's objection to new theories of jurisdiction, it would be wrong for us to ignore the government's attempt to ambush appellants with an alternative basis for deeming their vessel "without nationality." To the extent this contractual constraint on the government's ability to change course operates like a waiver, that limitation is simply a function of the way contracts and plea- bargaining work. The inclusion of facts extraneous to § 70502(d)(1)(C) in the plea agreements cannot, without some - 91 - linkage to a specified jurisdictional theory, open the door to the government's permissible reliance on such an alternative to validate an otherwise impermissible prosecution. At most, those stray facts create an ambiguity that precedent tells us must be resolved in appellants' favor. Certainly, the obligation to deal forthrightly with defendants who will be giving up important constitutional rights cannot be met with plea agreements that sub silentio -- at best -- or deceptively -- at worst -- enlarge the government's end of the bargain. Yet, our colleagues attempt to justify their choice to rely on a contrived plain-error analysis by discrediting the ways in which appellants responded to the government's shift in strategy. First, the majority notes that appellants have not sought to vacate their pleas as unknowing and involuntary in light of the government's assertion that the plea agreements covered rationales for deeming their vessel "without nationality" other than § 70502(d)(1)(C). Second, the majority observes that, in the supplemental brief requested by the panel in early 2019, appellants responded to the government's Matos-Luchi-based argument on its merits rather than asserting that the argument had been waived. This turning of the tables on appellants is another example of the remarkable lengths the majority is traveling to justify avoiding appellants' constitutional challenge to § 70502(d)(1)(C). Appellants admitted that the government's facts - 92 - establish their vessel's statelessness pursuant to § 70502(d)(1)(C), and they necessarily concede that, if § 70502(d)(1)(C) is constitutional, their pleas and convictions would stand (assuming their other challenges to the MDLEA also failed).28 In other words, appellants do not dispute that their pleas were knowing and voluntary based on the only ground relied upon by the government to secure them. It is patently absurd to suggest that, rather than challenging the constitutional legitimacy of the government's actual theory of jurisdiction, they should be seeking to undo their pleas -- more than seven years later and after Reyes-Valdivia served his entire sentence -- based on a counterfactual version of the record. The majority also suggests that, by arguing against the merits of the Matos-Luchi alternative, appellants gave up the argument that their plea agreements were reasonably understood to establish their vessel's statelessness only via § 70502(d)(1)(C). But the majority ignores and thereby distorts the significance of appellants' substantive rebuttal to the Matos-Luchi dicta. Appellants addressed Matos-Luchi on the merits only when responding to a series of questions posed to both parties by the panel, including whether there were other possible theories of 28 As described in the majority opinion, appellants also presented multiple arguments alleging violations of the Due Process Clause of the Constitution. - 93 - jurisdiction to support the prosecution given that, by its terms, § 70502(d)(1)(C) refers only to claims of registry, not -- as occurred here -- to claims of nationality. See supra note 22. The government relied heavily on Matos-Luchi in its response, even asserting -- contrary to the reality described in Section II above -- that "[b]efore the Appellants pleaded guilty, the Government's primary basis for determining that their vessel was 'subject to the jurisdiction of the United States' under 46 U.S.C. § 70502(c)(1) was that it bore no indicia of nationality and its master did not support his verbal claim of Costa Rican nationality." Appellants' response sensibly covered the possibility that our court would allow a post-conviction switch in jurisdictional theory based on Matos-Luchi in disregard of appellants' reasonable understanding of the plea agreements -- a step the majority has, in fact, lamentably taken.29 The majority's plain-error analysis relying on Matos-Luchi 29 is disturbing beyond the disregard of appellants' understanding of their plea agreements. At a minimum, the en banc court should be considering whether Matos-Luchi's dicta aligns with international law. If international law does require corroboration of an oral claim of nationality to establish a vessel's foreign status, appellants' prosecutions at least would be within Congress's authority under the Felonies Clause, even if improper given the government's sole reliance on § 70502(d)(1)(C) to obtain the guilty pleas. If Matos-Luchi is wrong, however, the prosecutions would be unconstitutional unless sustainable under § 70502(d)(1)(C) or our court's precedent on the protective principle -- issues the majority also refuses to address. - 94 - IV. Under Class v. United States, 138 S. Ct. 798 (2018), Reyes-Valdivia and Dávila-Reyes are entitled to challenge their convictions on the ground that Congress exceeded its constitutional authority when it enacted § 70502(d)(1)(C) as a basis for designating a vessel "without nationality." As the panel majority opinion shows, that challenge is legally complex -- requiring us to examine, inter alia, the Constitution's language, the Founding generation's understanding of that language, the legislative history of the MDLEA, our circuit's precedent on the protective principle, and the principles of international law governing vessels traveling on the high seas. Indeed, our court is now ruling on appellants' challenge for the third time, reflecting the difficulty of the issues and the undeveloped nature of our precedent. Twice, the panel confronted the merits of appellants' claims, once after a pause of more than a year for completion of the en banc proceedings in United States v. Aybar- Ulloa, 987 F.3d 1 (1st Cir. 2021) (en banc), a case that presented overlapping issues concerning the United States' authority to prosecute foreign nationals accused of drug-trafficking on the high seas. Now, for the first time, the court's dispositive ruling avoids seriously engaging with any aspect of the merits of appellants' claim. - 95 - The majority's justification for that avoidance depends on a non-existent plain-error scenario and a deeply problematic misuse of the plain-error standard. The plain-error doctrine sets a high threshold for remedying errors on appeal to "keep[] parties from hiding problems below" that could have "been fixed then and there." United States v. Romero, 906 F.3d 196, 205 n.4 (1st Cir. 2018); see also Puckett, 556 U.S. at 134 ("[T]he contemporaneous- objection rule prevents a litigant from 'sandbagging' the court -- remaining silent about his objection and belatedly raising the error only if the case does not conclude in his favor." (quoting Wainwright v. Sykes, 433 U.S. 72, 89 (1977))). Ignoring that rationale for the plain-error doctrine, the majority uses plain error as a convenient off-ramp. The government consistently relied on § 70502(d)(1)(C) to support the prosecutions, and appellants have consistently challenged the prosecutions as unconstitutional based on the government's reliance on that provision. Appellants never hid the ball, leaving no justification for invoking the plain-error rubric to avoid their claims. It is the government, abetted by the majority, that seeks to change the terms of the plea bargain. The majority's sidestepping of substantial issues of great import based on a contrived procedural ground is particularly disconcerting at this late stage of the case. At no point during the case's lengthy history in our court was there a suggestion - 96 - that the case should end because of a procedural default. Of course, that history would not justify ignoring a true procedural impediment to the en banc court's reaching the merits. But the procedural impediment on which the majority relies is an artifice in the name of constitutional avoidance with severe consequences for the practice of plea-bargaining. Nor should we forget the impact on the two individuals directly affected by the majority's dogged avoidance of the merits. Reyes-Valdivia and Dávila-Reyes, Costa Rican nationals who plausibly claimed Costa Rican nationality for their vessel, have vigorously pressed their constitutional challenge to § 70502(d)(1)(C), and they deserve to know -- after more than seven years -- whether they were lawfully prosecuted. Although Reyes-Valdivia completed his sentence, Dávila-Reyes remains incarcerated. Constitutional avoidance is an important principle. But it is not properly used here to escape confronting appellants' challenge to § 70502(d)(1)(C). Indeed, as an intermediate appellate court, we could perform an important service by exploring "the broader questions of international and constitutional law" acknowledged by the majority and attempting to crystalize the issues in a way that would be useful to the Supreme Court if it chose to review our decision. We do not minimize the "sensitive issues of U.S. foreign relations and national power" implicated by appellants' challenge to § 70502(d)(1)(C), but we cannot sidestep - 97 - such questions because of their sensitivity and import when properly raised. If we answer them incorrectly, the Supreme Court will tell us. In addition, with their avoidance, our colleagues forsake their obligation to address and clarify multiple unresolved issues in our own law on MDLEA prosecutions, including the role of the protective principle and the validity of the Matos-Luchi dicta as a basis for deeming a vessel "without nationality." These recurring issues deserve our attention now. Moreover, the dance the majority performs to avoid appellants' serious constitutional challenge undermines the Supreme Court's decision in Class to forgo the usual finality of unconditional guilty pleas to protect criminal defendants from prosecutions -- and, perhaps most importantly, imprisonments -- that the United States lacks authority to pursue. See Class, 138 S. Ct. at 805 (holding that an unconditional guilty plea does not bar a direct appeal where the defendant's claims "call into question the [g]overnment's power to 'constitutionally prosecute' him" (quoting United States v. Broce, 488 U.S. 563, 575 (1989))). Accordingly, we dissent and, based on the analysis set forth in the panel majority opinion, see Appendix, conclude that appellants' convictions should be reversed.30 The majority suggests that, if appellants' contentions did 30 not otherwise fail, their claims may be waived. The panel majority explained why appellants' plea agreements do not bar their appeals and why, pursuant to Class, their guilty pleas do not foreclose their constitutional claims. Those explanations are contained in Section III of the panel majority opinion. 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