*1144ORDER WITHDRAWING OPINION AND OPINION
ORDER
We have received a motion by the United States Attorney for the District of Nevada seeking modification of the written opinions in this case (both the majority opinion and the partial-concurrence-partial-dissent). For the reasons stated here, the motion is granted in part.
As for the majority opinion, the one modification that the motion seeks is its elimination of the word “recidivist” from this sentence:
To label such recidivist conduct as “unremarkable” is itself remarkable.
Because the motion mistakenly characterizes that usage as “inartful,” something should be said to dispel that notion. Webster’s Third New International Dictionary lists this as the primary definition and example of “recidivist” (true to the term’s medieval Latin and French etymology), before giving a secondary definition referring to criminal repeat offenders:
one who relapses or has suffered a relapse (some of the patients admitted are new cases, others are recidivists)
That mirrors the dictionary’s primary definition and example of “recidivism”:
a tendency to relapse into a previous condition or mode of behavior (a study of recidivism in mental patients)
In the context and place where “such recidivist conduct” appears in the opinion, then, the term’s usage clearly conforms to that first-listed common meaning.
Nonetheless we recognize the United States Attorney’s sensitivity to the fact that the term’s usage most familiar to lawyers is in connection with criminal repeat offenders, a connotation that was certainly not intended by the opinion. Accordingly we have substituted the phrase “such repeat-offender conduct” for “such recidivist conduct.”
As for the motion’s expressed concerns regarding the partial-concurrence-partial-dissent, that opinion has been revised to delete any references to the name of the Assistant United States Attorney who handled the case, as well as making certain other changes. Hence the original opinion is ordered withdrawn, and a new opinion has been substituted in its place.
OPINION
SHADUR, Senior District Judge.Kendrick Weatherspoon (“Weather-spoon”) appeals his conviction on one count of felon-in-possession of a firearm. Because we find that prosecutorial misconduct during the closing arguments affected the jury’s fair consideration of the evi■dence in the record, we reverse and remand for a new trial.
Factual and Procedural Background
At approximately 3 a.m. on August 22, 2002, Officer Shanan Kelly (“Kelly”) of the Las Vegas Metropolitan Police Department stopped a vehicle that had failed to use its turn signal. Inside were three individuals: Vaneshia Taylor (“Taylor”) in the driver’s seat, Weatherspoon in the front passenger seat and Donald Ray Harris (“Harris”) in the seat directly behind Weatherspoon. When a records check indicated that Weatherspoon had outstanding warrants, Kelly called in Officer Ray Kent (“Kent”) as backup and Weather-spoon was arrested. Taylor consented to a vehicle search that led to the discovery of a loaded semiautomatic handgun under the front passenger seat. Weatherspoon was then charged as a convicted felon in possession of a firearm in violation of 18 U.S.C. §§ 922(g)(1) and 924(a)(2).
*1145Neither officer had actually seen Weatherspoon in possession of the gun, and the forensic evidence was inconclusive. So the arrest was based instead on circumstantial evidence and on the contents of handwritten statements provided to police at the time of the arrest by Taylor and Harris. Taylor had then said that she saw Weatherspoon drop a black gun to the floor of the vehicle and slide it under the, seat immediately after the car was pulled over, while Harris asserted that he had seen Weatherspoon earlier in the evening with a black gun tucked into his waist.1
But the government’s case at trial was not as straightforward as those two statements might suggest. After the arrest Taylor fully recanted her statement and explained that she initially provided it (1) because the officers had threatened that she would herself be.charged with offenses if she did not implicate Weatherspoon and (2) because she feared that any such charges would lead her to lose custody of her children. Although Harris never recanted the content of his statement, he did acknowledge at trial that he had provided it as a “stipulation” for not being arrested on outstanding warrants.
Because Weatherspoon’s guilt depended on his possession of the firearm,2 and because the officers did not directly observe Weatherspoon with the gun, the two-day trial centered around the accuracy of the statements provided by Taylor, Harris and the two officers on the scene. Defense counsel, arguing that the Taylor and Harris statements should not be credited by the jury because they were supplied in response to police pressure, focused instead on testimony by each of them — both before a grand jury and at trial — that was far more questionable in terms of ascribing possession of the gun to Weatherspoon. And the defense also challenged the credibility of Harris’ testimony by suggesting that he had an incentive to implicate Weatherspoon: to avoid being arrested himself under state law..
For its'part, the government relied on the testimony of Officers Kelly and Kent, in which they denied exerting improper influence over the submission of the Taylor and Harris statements, to argue that those statements constituted strong evidence of possession. , And the prosecution also questioned the credibility of Taylor’s claims of police pressure by raising the existence of a sexual relationship between Taylor and Weatherspoon.
Ultimately the jury' returned a guilty verdict against Weatherspoon on the single count of felon-in-possession of a firearm. Weatherspoon urges that the verdict was impermissibly tainted by improper statements made by the prosecutor during closing arguments, and he now appeals.
Prosecutorial Misconduct
Analysis of a claim of prosecutorial misconduct focuses on its asserted impropriety and substantial prejudicial effect (see, *1146e.g., United States v. Yarbrough, 852 F.2d 1522, 1539 (9th Cir.1988)). We must therefore determine at the outset whether the prosecutor made improper statements during the course of the trial, after which we will turn to the effect of any such misconduct.
As to the threshold issue of impropriety, we conclude that prosecutorial misconduct was clearly involved, both (1) because the prosecutor vouched for the credibility of witnesses and (2) because he also made arguments designed to encourage the jury' to convict in order to alleviate social problems. We address those issues seriatim.
“Vouching consists of placing the prestige of the government behind a witness through personal assurances of the witness’s veracity, or suggesting that information not presented to the jury supports the witness’s testimony” (United States v. Necoechea, 986 F.2d 1273, 1276 (9th Cir.1993)). On that score Weather-spoon contends that the prosecutor vouched for the credibility of all of the major witnesses in his case: Kelly, Kent, Taylor and Harris.
At the very outset of his argument the prosecutor said this in discussing the testimony provided by the officers:
We, first of all, heard from Officer Kelly, Metro officer; credible police officer.
That statement garnered an objection, and the district court instructed the prosecutor not to vouch. Undaunted, the prosecutor returned to the theme of police credibility in his rebuttal, telling the jury that the officers “had no reason to lie in this case or not tell the truth.” After defense counsel’s objection to that statement on vouching grounds was overruled, the prosecutor went even further:
They had no reason to come in here and not tell you the truth. And they took the stand and they told you the truth. I guess, if you believe Mr. Valladeres [defense counsel], they must have lied at the scene there; they came into this court and they lied to you; they lied to this judge; they lied' to me; they lied to my agent, Agent Baltazar. I guess they lied to the dispatcher when they called it in. These are officers that risk losin’ their jobs, risk losin’ their pension, risk losin’ their livelihood. And, on top of that if they come in here and lie, I guess they’re riskin’ bein’ prosecuted for perjury. Doesn’t make sense because they came in here and told you the truth, ladies and gentlemen.
That statement was clearly improper. In United States v. Combs, 379 F.3d 564, 574-76 (9th Cir.2004) we recently considered similar statements made by a prosecutor during rebuttal and found that they constituted impermissible vouching because the prosecutor “plainly implied that she knew [an agent] would be fired for committing perjury and that she believed no reasonable agent in his shoes would take such a risk” (id. at 575). To be spre, the present situation is not quite as egregious as that in Combs, because the prosecutor there instructed the jury that they could be “darn sure he [the agent] would get fired for perjuring himself’ (id. at 568), while no such firm assurance was provided here. But no such modest shade of difference in the level of impropriety calls for a different result, for the prosecutor here (like the prosecutor in Combs) clearly urged that the existence of' legal and professional repercussions served to ensure the credibility of the officers’ testimony. That suffices for the statement to be considered improper as vouching based upon matters outside the record (see, e.g., United States v. Boyd, 54 F.3d 868, 871-72 (D.C.Cir.1995), collecting cases from various circuits and cited with approval in Combs, 379 F.3d at 574-75).
Next Weatherspoon directs us to prosecutorial vouching statements regarding *1147Taylor and Harris that were made during closing arguments and went unchallenged:
[Taylor’s] statement about being threatened I don’t believe is truthful, ladies and gentlemen.
The point, ladies and gentlemen, is he told the truth in that handwritten statement that he gave on that morning, he told the truth when he came into the Grand Jury under oath, and he was in front of you today and told the truth to you.
It is true that “we have recognized that prosecutors must have reasonable latitude to fashion closing arguments, and thus can argue reasonable inferences based on the evidence, including that one of the two sides is lying” (Necoechea, 986 F.2d at 1276). But even when grounded in an inference from the evidence, a prosecutorial statement may nevertheless be considered impermissible vouching if it “placets] the prestige of the government behind the witness” by providing “personal assurances of a witness’s veracity”, (United States v. Roberts, 618 F.2d 530, 533 (9th Cir.1980); see also United States v. Kerr, 981 F.2d 1050, 1053 (9th Cir.1992) (“A prosecutor has no business telling the jury his individual impressions of the evidence”)).
Vouching of that sort is dangerous precisely because a jury “may be inclined to give weight to the prosecutor’s opinion in assessing the credibility of witnesses, instead of making the independent judgment of credibility to which the defendant is entitled” (United States v. McKoy, 771 F.2d 1207, 1211 (9th Cir.1985); see also United States v. Young, 470 U.S. 1, 18-19, 105 S.Ct. 1038, 84 L.Ed.2d 1 (1985)). It is up to the jury — and not the prosecutor — to determine the credibility of a witness’ testimony. All of the cited prosecutorial statements were improper because they skewed the jury’s ability to make that determination.3
At this point it is important to identify the mistaken premise on which our esteemed colleague’s partial dissent in that regard rests. It points to a footnote sentence in the nearly half-century-old Lawn v. United States, 355 U.S. 339, 359 n. 15, 78 S.Ct. 311, 2 L.Ed.2d 321 (1958) for the proposition that a prosecutor’s statement of personal opinion about a witness’ credibility has only a single vice: It must not convey the impression that the prosecutor knows facts that the jury does not. Not so — as the partial dissent has acknowledged at its outset, over a quarter century later the Supreme Court in Young, 470 U.S. at 18-19, 105 S.Ct. 1038 (emphasis added) identified not one but two reasons why prosecutors must not simply place their personal opinions as to witness credibility before the jury, and it is the second of those dangers that is presented .in spades here:
The prosecutor’s vouching for the credibility of witnesses and expressing his personal opinion concerning the guilt of .the accused pose two dangers: such comments can convey the impression *1148that evidence not presented to the jury, but known to the prosecutor, supports the charges against the defendant and can thus jeopardize the defendant’s right to be tried solely on the basis of the evidence presented to the jury; and the prosecutor’s opinion carries with it the imprimatur of the Government and may induce the jury to trust the Government’s judgment rather than its own view of the evidence. See Berger v. United States, 295 U.S., at 88-89, 55 S.Ct. 629.4
In each instance the prosecutor’s message is identical:
I believe [do not believe] the testimony of Witness A. Therefore you should believe [not believe] Witness A too [either].
It is of course the implicit “therefore” contained in that message that is improper. Neither our colleague nor anyone else has ever suggested a legitimate basis for a prosecutor’s flat-out statement of his or her personal opinion as to witness credibility in a system that, like ours, vests the sole determination regarding such credibility (like all other factual determinations) with the jury. Nothing then flows from an extended discussion of cases that address the other “vouching” danger that was identified in Young (and Lawn).
On that score, it is wholly beside the mark to suggest that a witness’ challenge to the credibility of another witness during the trial somehow validates the prosecutor’s repeated statements of his own belief as to such credibility in the course of closing argument, as though such statements were other than constitutionally prohibited vouching. Indeed, just the opposite is true: the existence of a dispute in the evidence as to the credibility of a witness — a matter that by definition is for the jury to resolve — makes the prosecutor’s placement of his thumb on the scales all the more impermissible. For any prosecutor to state his own view that witnesses are credible or not credible, or indeed to say flat out — three times over in rapid succession — that a witness “told the truth,” rather than to invite the jury to make all of those determinations based on evidence to which the prosecutor points, cannot fairly be labeled as “no more than a comment on the evidence that one would expect in a hard-fought case such as this,” or as “nothing more than an unremarkable comment based upon the evidence,” or as “merely a comment on the evidence.”
In that respect we stress that the ethical bar is set higher for the prosecutor than for the criminal defense lawyer — a proposition that has been clear for at least seven decades (see Berger v. United States, 295 U.S. 78, 88, 55 S.Ct. 629, 79 L.Ed. 1314 (1935); and see also such cases as United States v. Modica, 663 F.2d 1173 (2d Cir.1981) as well as the ABA Standards for Criminal Justice § 3 — 5.8(b)). Although to be sure no lawyer, either public or private, should lay his or her own credibility on the line by expressing his or her own opinion about a witness’ believability, the difference is that a private lawyer’s impropriety in that respect carries no implication of official governmental support. And in this particular instance, it is surely worth noting that the selfsame prosecutor has engaged in exactly the same kind of vouching conduct in two instances that has led other panels of this court to upset convictions obtained by that prosecutor (see the unpublished opinions in United States v. Williams, 112 Fed.Appx. 581 (9th Cir.*11492004) and United States v. Green, 119 Fed.Appx. 133 (9th Cir.2004)). To label such repeat-offender conduct as' “unremarkable” is itself remarkable.
Weatherspoon also argues that the prosecutor impermissibly urged the jury to convict in order to alleviate societal problems. In his rebuttal, the prosecutor encouraged the jury on several occasions to feel comfortable entering a guilty verdict — for example:
Convicting Mr. Weatherspoon is gonna make you comfortable knowing there’s not convicted felons on the street with loaded handguns, that there’s not convicted felons carrying around semiautomatic .... ”
At that point defense counsel objected, and the judge instructed the prosecutor to confine his arguments to “guilt or not guilt.” Undeterred, the prosecutor continued by reiterating that “[y]ou can feel comfortable knowing there’s a convicted felon that’s been found guilty of possessing a loaded firearm, a fully loaded semiautomatic weapon.”
Shortly thereafter the prosecutor returned to the same theme, telling the jury that “the law of being a felon in possession of a firearm, that protects a lot of people out there too.” Again an objection followed, and the judge instructed the prosecutor to “just talk about guilt or nonguilt.” And again the prosecutor failed to respond meaningfully to that directive, instead repeating his argument that “finding this man guilty is gonna protect other individuals in this community.” Another objection followed, but this time the judge overruled the objection and instructed defense counsel:
When there is a serious objection, I will rule in your favor on it. At the moment, please let the Government complete its argument.
That entire line of argument, made even more indefensible by its repetition in the face of directions to desist, was improper. We have consistently cautioned against prosecutorial statements designed to appeal to the passions, fears and vulnerabilities of the jury, as in United States v. Koon, 34 F.3d 1416, 1443 (9th Cir.1994), quoting United States v. Monaghan, 741 F.2d 1434, 1441 (D.C.Cir.1984):
A prosecutor may not urge jurors to convict a criminal defendant in order to protect community values, preserve civil order, or deter future lawbreaking. The evil lurking in such prosecutorial appeals is that the defendant will be convicted for reasons wholly irrelevant to his own guilt or innocence. Jurors may be persuaded by such appeals to believe that, by convicting a defendant, they will assist in the solution of some pressing -social problem. The amelioration of society’s woes is far too heavy a burden for the individual criminal defendant to bear.
It is true that the prosecutor did not engage in the even more egregious offense of “pointing] to a particular crisis in our society and askfing] the jury to make a statement” (United States v. Leon-Reyes, 177 F.3d 816, 823 (9th Cir.1999)). But the statements here nonetheless violated the Noow-identified principle. Weatherspoon’s guilt at trial depended entirely on proof that he was in possession of a gun at the time that the car was pulled over. Those prosecutorial urgings — especially the later ones encouraging a conviction to protect other individuals in the community — spoke not to that question, but rather to the potential social ramifications of the jury’s reaching a guilty verdict.5 They were *1150clearly designed to encourage the jury to enter a verdict on the basis of emotion rather than fact. As such, they were irrelevant and improper.
Despite all that has been said to this point, the prosecutor urges that his statements should be considered proper because he was simply making “invited replies” to arguments made by defense counsel during closing argument. Quite apart from the fact that some of the prosecutor’s improper statements preceded that closing argument so that no “invitation” then existed, plus the added fact that the prosecutor never objected to any of the now-complained-of arguments by defense counsel, that attempted explanation wholly misunderstands the doctrine of “invited response” as applied in Young, 470 U.S. at 12, 105 S.Ct. 1038. There the Supreme Court explained that in order to undertake a contextual review of prosecutorial misconduct, “the reviewing court must not only weigh the impact of the prosecutorial remarks, but must also take into account defense counsel’s opening salvo” (id.).
But that does not at all mean that whenever a defense counsel attacks the credibility of witnesses the prosecutor can respond with vouching statements. To the contrary, we have concluded that “[a]t-tacks on the credibility of a defense witness are legitimate tools of advocacy and do not, standing alone, trigger the invited response rule” (United States v. Smith, 962 F.2d 923, 934 (9th Cir.1992)). And that is particularly true when, as here, the defense attacks were grounded in inferences from the evidence rather than defense counsel’s personal assurances.
Moreover, even if any defense statements were somehow viewed as opening the door to a prosecutorial response, the particular response chosen here would still be inappropriate because “the prosecution is not allowed to use improper tactics even in response to similar tactics by the defense” (United States v. Sarkisian, 197 F.3d 966, 990 (9th Cir.1999); see also Smith, 962 F.2d at 934). Prosecutors must understand the different — and special — place that they occupy in the criminal justice system (see, e.g., United States v. Kojayan, 8 F.3d 1315, 1323 (9th Cir.1993) and cases cited there). Though we do not of course countenance, let alone encourage, excesses on the part of defense counsel, the prosecutor’s role as representative of the United States (the named plaintiff in every federal criminal prosecution) demands the exercise of far better restraint and better judgment than was exhibited here. In short, nothing about the invited response doctrine rescues the prosecutor’s statements from impropriety — even to the extent that some (though not all) of them might be viewed as invited, the statements did far more than simply “right the scale.”
Effect of the Prosecutorial Misconduct
Next we must determine whether the improper statements identified in the preceding section were so prejudicial to Weatherspoon’s substantial rights that a new trial is required. As taught in such cases as United States v. Hinton, 31 F.3d 817, 824 (9th Cir.1994):
Where defense counsel objects at trial to acts of alleged prosecutorial misconduct, we review for harmless error on defendant’s appeal; absent such an objection, *1151we review under the more deferential plain error standard.
Weatherspoon raised objections at trial to some but not all of the statements that he now challenges as improper. Even so, he argues that a harmless error analysis should be applied to the entirety of his appeal because his failures to object were attributable to the district court’s demonstrated unwillingness to entertain his objections. But we need not venture into that fray, because the misconduct at issue here requires reversal even under the more restrictive plain error standard, under which reversal is appropriate “only if the prosecutor’s improper conduct so affected the jury’s ability to consider the totality of the evidence fairly that it tainted the verdict and deprived [Weather-spoon] of a fair trial” (Smith, 962 F.2d at 935). And to that end we must review the potential for prejudicial effect in the context of the entire trial (Young, 470 U.S. at 16, 105 S.Ct. 1038).
“To determine whether the prosecutor’s misconduct affected the jury’s verdict, we look first to the substance of a curative instruction” (Kerr, 981 F.2d at 1053). In that respect, even in the absence of objections by defense counsel, a “trial judge should bfe alert to deviations from proper argument and take prompt corrective action as appropriate” (id. at 1054).
In this instance the trial was doubly flawed: Objections were indeed made by defense counsel, and whatever curative statements were provided by the district judge were inadequate. As for the objections, some were overruled, those that were sustained did not produce any meaningful alteration of the prosecutor’s arguments, and the manner in which such objections were sustained unfortunately did not deliver the required strong cautionary message (indeed, as quoted earlier, one response by the trial judge actually chilled further objections). Such failures to correct the improper statements at the time they were made cannot be salvaged by the later generalized jury instruction remind-, ing jurors that a lawyer’s statements during closing argument do not constitute evidence (United States v. Simtob, 901 F.2d 799, 806 (9th Cir.1990)). In short, the curative instructions offered here did not neutralize the harm of the improper statements because “[t]hey did not mention the specific statements of the prosecutor and were not given immediately after the damage was done” (Kerr, 981 F.2d at 1054).
. Another important factor contributing to the prejudicial effect of improper statements is the strength of the case against a defendant. When the case is particularly strong, the likelihood that prosecutorial misconduct will affect the defendant’s substantial rights is lessened because the jury’s deliberations are less apt to be influenced. But as the case becomes progressively weaker, the possibility of prejudicial effect grows correspondingly. Moreover, the possibility of prejudicial effect stemming from vouching is increased in cases where credibility is of particular importance (Necoechea, 986 F.2d at 1276).
Despite the trial prosecutor’s contentions to the contrary in the government’s brief and again in oral argument, the case against Weatherspoon was not particularly strong and depended in large measure on witness credibility. Hence the already-described instances of prosecutorial misconduct — -and especially of vouching— present a strong possibility of prejudicial effect. In this respect the case is again similar to Kerr, 981 F.2d at 1054, where we reversed for plain error because the case was close and because “the testimony of the ... ‘vouched’ witnesses was crucial to the government’s case and the prosecutor’s argument.”
*1152 Conclusion
This was a comparatively close case that boiled down to a battle over credibility. In that context, prosecutorial statements that vouch for the credibility of witnesses and that encourage the jury to act based on considerations other than the particularized facts of the case pose a real danger to the defendant’s right to a fair trial. Because that danger was not effectively mitigated by curative instructions from the district judge, we conclude that the prosecutorial misconduct here “affected the jury’s ability to consider the totality of the evidence fairly” (Smith, 962 F.2d at 935). We therefore REVERSE for plain error and REMAND for a new trial.
. Harris’ account of the events leading up to the arrest was the most hotly contested at trial. In addition to his statement to police, Harris told a grand jury that he saw Weather-spoon place a gun under the front seat. But at trial Harris hedged and stated instead that he could not see Weatherspoon clearly because he was seated directly behind him and that all he saw was a "motion like he was puttin’ it away.” And a federal public defender investigator testified that during an interview Harris said that he had never seen Weatherspoon with a gun on the day of the arrest. At trial Harris sought to explain that statement away by suggesting that it was attributable to confusion on his part as to the meaning of the word "day."
. Both> of the other elements necessary for conviction on the charged offense — Weather-spoon’s status as a convicted felon and the fact that the weapon had traveled in interstate commerce — were stipulated to at trial.
. In drawing the line between acceptable statements grounded on inferences from the evidence and unacceptable statements representing an improper suggestion of personal opinion, we have been especially sensitive to the form of prosecutorial statements — so that use of the prefatory phrase "I submit” has been preferred to the use of "I think,” in part because the latter is more likely to lead the jury to give undue credit to the statement that follows (compare Necoechea, 986 F.2d at 1279 ("I submit to you”) with Kerr, 981 F.2d at 1053 (9th Cir.1992) ("I think”)). Both statements here fall on the unacceptable side of the line, because there is nothing in their form to convey to the jury that the statements were intended only as a submission for its consideration and because they would therefore be reasonably understood by the jury as personal assurances.
. [Footnote by this Court] It should go without saying that the express recognition of the second of those evils in Young, which has been further recognized and applied since then not only in this Circuit's cases we have cited and quoted but also in a host of cases in other Circuits, cannot have been somehow trumped by the more limited one-sentence pronouncement in the Lawn footnote 27 years earlier.
. And the statements were clearly designed to emphasize Weatherspoon's status as a "convicted felon.” Although that status is obviously relevant to the case as an element of the offense charged, it was stipulated to the jury and so should not have been posed as an issue *1150in the way that it was. Instead its use here was patently designed to persuade the juiy to convict Weatherspoon more because he is a generally dangerous individual than because he violated a particular law in this instance. In that regard, see Commonwealth of N. Mariana Islands v. Mendiola, 976 F.2d 475, 487 (9th Cir.1993):
While commentary on a defendant’s future dangerousness may be proper in the context of sentencing, it is highly improper during the guilt phase of a trial.