delivered the opinion of the Court.
A special court-martial composed of officer and enlisted members convicted appellant, contrary to his pleas, of willfully disobeying a lawful order given by a superior commissioned officer, in violation of Article 90, Uniform Code of Military Justice (UCMJ), 10 USC § 890. He was sentenced to a bad-conduct discharge and confinement for two months. The convening authority approved these results, and the Court of Criminal Appeals affirmed. 54 MJ 936 (2001).
On appellant’s petition, we granted review the following issues:
I. WHETHER THE MILITARY JUDGE ABUSED HIS DISCRETION WHEN HE EXCLUDED RELEVANT EVIDENCE REGARDING THE SAFETY AND EFFICACY OF THE ANTHRAX VACCINE WHICH WAS NECESSARY TO APPELLANT’S AFFIRMATIVE DEFENSE UNDER R.C.M. 916(h).
II. WHETHER THE AIR FORCE COURT OF CRIMINAL APPEALS ERRED IN ITS APPLICATION OF ARTICLE 66(c) WHEN IT CONCLUDED THAT APPELLANT WAS NOT ENTITLED TO A PRESUMPTION OF INNOCENCE.
III. WHETHER THE AIR FORCE COURT OF CRIMINAL APPEALS ABUSED ITS DISCRETION WHEN IT AFFIRMED APPELLANT’S SENTENCE DESPITE THE AIR FORCE’S DE FACTO POLICY THAT ANTHRAX REFUSAL CASES WILL BE DISPOSED OF BY NONJUDICIAL PUNISHMENT AND ADMINISTRATIVE DISCHARGE.
*396For the reasons set forth below, we remand to the Air Force Court of Criminal Appeals for further consideration of Issue II.
I. LITIGATION AT TRIAL CONCERNING THE ORDER TO RECEIVE THE ANTHRAX VACCINATION
A. BACKGROUND
Anthrax is an infectious animal disease that can be employed as a deadly biological weapon. Over the last decade, the Department of Defense (DoD) has focused attention on the possibility that such weapons might be used against deployed U.S. forces. As a countermeasure, DoD, for a period of time, implemented a program involving widespread vaccination of U.S. military personnel. The program subjected numerous members of the armed forces to a series of six vaccinations designed to counter the effects of any exposure to anthrax.
Appellant, who was stationed in the United States, received five of the six vaccinations without objection. In 1999, he was deployed to Saudi Arabia, where he declined to receive the sixth vaccination. On December 21, his squadron commander ordered him to receive the required vaccination. Appellant refused to obey the order, and he received nonjudicial punishment under Article 15, UCMJ, 10 USC § 815, for disobedience of the order. The nonjudicial punishment consisted of reduction from pay grade E-4 to E-l and a suspended forfeiture of $483.00 per month for two months.
Appellant’s commander issued appellant a new order on January 7, 2000, directing that he receive the anthrax vaccination within 24 hours. On January 8, appellant informed his commander that he would not obey the order. Appellant’s refusal occurred after he had considered articles in the media and testimony in congressional proceedings raising questions about the safety and effectiveness of the anthrax vaccine.
Appellant was charged with a violation of Article 90, UCMJ, which prohibits willful disobedience of a lawful order from a superior commissioned officer. The charge was referred to a special court-martial. During pretrial proceedings, the prosecution asked the military judge to rule that the order was lawful. The defense expressly stated that it would not contest the lawfulness of the order. The military judge ruled that the order was lawful, and he advised the parties that he would so instruct the members of the court-martial.
The prosecution then moved to preclude the defense from introducing evidence challenging the safety and effectiveness of the vaccination program. The defense objected, contending that such evidence was central to the defense ease, which would be based upon the defenses of duress and necessity. The military judge granted the prosecution’s motion. The military judge indicated that the defense of duress was unavailable because it requires an unlawful threat from a human being, and that the defense of necessity was unavailable because it requires a threat from a natural physical force—neither of which was present in this case. The military judge reasoned, in effect, that any threat to appellant’s health came from human implementation of a lawful policy decision, not from an unlawful threat or a natural physical force. On appeal, appellant contends that the military judge committed prejudicial error by not permitting him to present pertinent evidence regarding the defenses of duress and necessity.
B. DISCUSSION
In United States v. Rockwood, 52 MJ 98 (1999), we considered the nature of the duress defense in the military justice system, as well as the question of whether the defense of necessity is available in courts-martial. With respect to duress, we observed: (1) “[cjlassically, duress was seen as a defense to crime if the defendant was compelled or coerced to commit the crime by some human agency, under a threat of serious imminent harm to the defendant or others”; (2) “[f]or the defense of duress to apply, the crime committed must have been of lesser magnitude than the harm threatened”; (3) “the duress must [have] consisted] of threatening conduct which produced in the defendant ... a reasonable fear of ... immediate (or immi*397nent) ... death or serious bodily harm”; and (4) “[a]n obviously safe avenue of escape before committing the prohibited act nullifies the defense.” Id. at 112 (citing 1 Wayne R. LaFave & Austin W. Scott, Jr., Substantive Criminal Law 614-27 (1986); Rollin M. Perkins & Ronald N. Boyce, Criminal Law 1959-65 (3d ed.1982); United States v. Vasquez, 48 MJ 426, 429-30 (1998)(internal quotations and emphasis omitted)).
With respect to the defense of necessity, we noted: (1) necessity “was traditionally seen as a choice of evils defense” in which “the pressure of circumstances was not brought by human agency, but by the situation itself’; and (2) “[t]he defendant’s belief that his actions were necessary must have been reasonable, and there must have been no alternative that would have caused lesser harm.” Id. at 112 (citing 1 LaFave & Scott, supra, at 627-31, 635, 638; Perkins & Boyce, supra, at 1069; United States v. Bailey, 444 U.S. 394, 410, 100 S.Ct. 624, 62 L.Ed.2d 575 (1980)(footnote and internal quotations omitted)).
In our discussion of applicable military law, we took note of R.C.M. 916(h), Manual for Courts-Martial, United States (2000 ed.) * which provides for the defense of duress. We also observed that the defense of necessity was not specifically provided for in the Manual for Courts-Martial, and that under the circumstances of the case it was unnecessary to decide whether, as a matter of law, it should be available in the military justice system. Id. at 113-14.
Appellant places primary reliance on R.C.M. 916(h), which states:
It is a defense to any offense except killing an innocent person that the accused’s participation in the offense was caused by a reasonable apprehension that the accused or another innocent person would be immediately killed or would immediately suffer serious bodily injury if the accused did not commit the act. The apprehension must reasonably continue throughout the commission of the act. If the accused has any reasonable opportunity to avoid committing the act without subjecting the accused or another innocent person to the harm threatened, this defense shall not apply.
Appellant contends that a plain reading of the text provides a defense to a charge of disobeying a lawful order if the accused had a reasonable belief that compliance with the order would result in death or serious bodily injury to the accused or another person. According to appellant, the military judge erred in two respects: first, by grafting onto the rule a requirement that the duress result from the unlawful threat of a human being; and second, by declining to consider the necessity defense in the absence of a threat imposed by a natural physical force.
Appellant’s narrow reading of R.C.M. 916(h) would permit a member of the armed forces to disobey a lawful order if the servicemember had a reasonable apprehension that he or she, or another innocent person, would immediately be killed or suffer serious bodily injury if he or she complied with the order. Such an interpretation suggests that the President designed the rule to alter one of the core values of military service—the willingness of the individual to sacrifice his or her life or well-being for the sake of the nation. As the Supreme Court has emphasized, “[t]he essence of military service ‘is the subordination of the desires and interests of the individual to the needs of the service.’ ” Goldman v. Weinberger, 475 U.S. 503, 507, 106 S.Ct. 1310, 89 L.Ed.2d 478 (1986)(quoting Orloff v. Willoughby, 345 U.S. 83, 92, 73 S.Ct. 534, 97 L.Ed. 842 (1953)).
The requirement to place the needs of the nation above a servicemember’s personal welfare applies in peacetime as well as in war. “[I]t is the primary business of armies and navies to fight or be ready to fight should the occasion arise.” United States ex rel. Toth v. Quarles, 350 U.S. 11, 17, 76 S.Ct. 1, 100 L.Ed. 8 (1955). Every day, members of the armed forces engage in operational missions or training activities in which there is a risk of death or serious bodily injury to themselves or others. Although the armed forces rely on unit cohesion and leadership to *398foster a willingness to undertake such risks, legal sanctions are available to promote obedience should positive measures prove insufficient. Congress has expressly provided criminal sanctions in Article 90, UCMJ, as well as Articles 91 and 92, UCMJ, 10 USC §§ 891 and 892, for failure to obey a lawful order, including authority in Article 90(2) for capital punishment in time of war for disobedience of the lawful order of a superior commissioned officer.
The President’s guidance with respect to the disobedience offenses embodies longstanding military law. “An order requiring the performance of a military duty or act may be inferred to be lawful and it is disobeyed at the peril of the subordinate.” Paragraph 14c(2)(a)(l), Part IV, Manual, supra. “The order must relate to military duty, which includes all activities reasonably necessary to accomplish a military mission, or safeguard or promote the morale, discipline, and usefulness of members of a command and directly connected with the maintenance of good order in the service.” Id. at para. 14c(2)(a)(iii). When a commander gives an order that is reasonably necessary to accomplish the mission—including an order involving protective measures, such as defensive positioning, wearing protective armor, or taking a vaccine to counter a biological weapon—the servicemember is obligated to obey or face punishment under Articles 90, 91, or 92, UCMJ. If servicemembers could disobey lawful orders to participate in military training or operations out of a reasonable apprehension that they or others might suffer death or serious bodily injury, the President’s guidance in paragraph 14c(2)(a) Part IV, Manual, supra, would be rendered meaningless.
In light of the foregoing, it would be inappropriate to read the President’s guidance on the duress defense in R.C.M. 916(h) Manual, supra, in isolation. Instead, it must be read in conjunction with the guidance on disobedience of lawful orders and the essential purposes of military law. In that context, the military judge correctly ruled that the duress defense in R.C.M. 916(h) should be viewed in a manner consistent with the requirement in prevailing civilian law that the threat emanate from the unlawful act of another person. Likewise, if the defense of necessity applies in the military justice system—a question which we need not resolve at this time— similar considerations would call for an application of the prevailing civilian doctrine regarding the requirement for the necessity to arise from a natural force, as opposed to a human action.
As we noted in Rockwood, supra, “[tjhere may indeed be unusual situations in which an assigned military duty is so mundane, and the threat of death or grievous bodily harm ... is so clearly defined and immediate, that consideration might be given to a duress or necessity defense.” 52 MJ at 114. This is not such a case. The evidence offered at trial demonstrated that the vaccination program was designed and implemented as a defensive measure in the face of a significant military threat. Assuming the validity of the data provided by appellant concerning the risk of adverse effects from the vaccination, such information does not demonstrate that the purpose of the vaccination program was “mundane” or that such risks were so immediate and widespread as to undermine its purpose.
The foregoing discussion is based on the premise—not challenged by appellant in this case—that the order was lawful. A service-member charged with a disobedience offense may challenge the lawfulness of the order on a variety of grounds, e.g., that the order directed the commission of a crime; that the issuing officer lacked authority; that the order did not relate to a military duty; that it interfered with private rights or personal affairs without a valid military purpose; that it was solely designed to achieve a private purpose; that it conflicted with a person’s statutory or constitutional rights. See para. 14c(2)(a)(i)-(iv), Part IV, Manual, supra; United States v. New, 55 MJ 95 (2001). In the present case, however, appellant chose not to challenge the lawfulness of the order he received to participate in the anthrax vaccination program. Accordingly, we have no occasion in this case to determine whether the program is based upon lawful authority or whether there are other legal grounds for *399questioning the program. Based on the foregoing, we resolve this issue against appellant.
II. APPLICABILITY OF THE PRESUMPTION OF INNOCENCE DURING INTERMEDIATE APPELLATE REVIEW UNDER ARTICLE 66(c)
A. BACKGROUND
Article 66(c), UCMJ, 10 USC § 866(c) provides:
In each case referred to it, the Court of Criminal Appeals may act only with respect to the findings and sentence as approved by the convening authority. It may affirm only such findings of guilty and the sentence or such part or amount of the sentence, as it finds correct in law and fact and determines, on the basis of the entire record, should be approved. In considering the record, it may weigh the evidence, judge the credibility of witnesses, and determine controverted questions of fact, recognizing that the trial court saw and heard the witnesses.
Article 66(e) requires the Courts of Criminal Appeals to conduct a de novo review of legal and factual sufficiency of the case. See United States v. Cole, 31 MJ 270, 272 (CMA 1990). The court may affirm a conviction only if it concludes, as a matter of factual sufficiency, that the evidence proves appellant’s guilt beyond a reasonable doubt. United States v. Sills, 56 MJ 239, 240-41 (2002); United States v. Turner, 25 MJ 324, 324-25 (CMA 1987). Although the court in the present case discussed the theoretical basis for a lesser standard of proof, it ultimately concluded that the evidence was sufficient to demonstrate appellant’s guilt beyond a reasonable doubt, thereby mooting any impact from its discussion of the lesser standard. See 54 MJ at 941.
In the course of its discussion of factual sufficiency, the court also rejected appellant’s suggestion that appellate review for factual sufficiency under Article 66(c), UCMJ, required the court to apply the “presumption of innocence.” Id. at 940. The “presumption of innocence” is a longstanding feature of both military and civilian law and is set forth in the statutory requirement that, prior to findings, the members of a court-martial must be instructed “that the accused must be presumed to be innocent until his guilt is established by legal and competent evidence beyond a reasonable doubt.” See Art. 51(c)(1), UCMJ, 10 USC § 851(c)(1). The instruction, which does not literally employ a presumption, reminds the members of a critical fact—that the accused, as a matter of law, is innocent unless the members are satisfied the prosecution has proved each required element of the offense beyond a reasonable doubt. See 1 Barbara E. Bergman & Nancy Hollander, Wharton’s Criminal Evidence, §§ 2:2, 3:10, at 23, 169-70 (15th ed.1997). As a practical matter, the presumption of innocence serves to underscore the instruction that the members may not presume that the defendant is guilty simply because charges have been referred to trial. See Military Judges’ Benchbook, Dept, of the Army Pamphlet 27-9 (Sept. 30, 1996) at 2-5.
At the appellate level, different considerations apply. The Court of Criminal Appeals is required to conduct a de novo review of the entire record of a trial, which includes the evidence presented by the parties and the findings of guilt. Such a review involves a fresh, impartial look at the evidence, giving no deference to the decision of the trial court on factual sufficiency beyond the admonition in Article 66(c), UCMJ, to take into account the fact that the trial court saw and heard the witnesses.
In the performance of its Article 66(c), UCMJ, functions, the Court of Criminal Appeals applies neither a presumption of innocence nor a presumption of guilt. The court must assess the evidence in the entire record without regard to the findings reached by the trial court, and it must make its own independent determination as to whether the evidence constitutes proof of each required element beyond a reasonable doubt. In contrast to the lay members who serve on courts-martial, the mature and experienced judges who serve on the Courts of Criminal Appeals are presumed to know and apply the law correctly without the necessity *400of a rhetorical reminder of the “presumption of innocence.”
In addition to reminding the fact-finder to not employ a presumption of guilt, the presumption of innocence also reflects allocation of the burden of proof. See Bell v. Wolfish, 441 U.S. 520, 533, 99 S.Ct. 1861, 60 L.Ed.2d 447 (1979)(citing Taylor v. Kentucky, 436 U.S. 478, 485, 98 S.Ct. 1930, 56 L.Ed.2d 468 (1978)). During review under Article 66(c), UCMJ, an appellant does not bear the burden of raising doubts about the trial-level finding of guilty. If the decision of the Court of Criminal Appeals raises substantial questions as to whether there has been an appropriate allocation of the burden, our Court cannot rely on the presumption that the court below applied the law correctly, and a remand is required to ensure that the court below applies a level playing field. See United States v. Troutt, 8 USCMA 436, 439, 24 CMR 246, 249 (1957). The opinion of the court below in the present case raises such questions. Instead of describing the approach that it would apply in lieu of the presumption of innocence, the court below cited Herrera v. Collins, 506 U.S. 390, 113 S.Ct. 853, 122 L.Ed.2d 203 (1993). 54 MJ at 941. Herrera, however, involved the appellate issue of whether federal habeas corpus relief is appropriate in light of newly discovered evidence—an issue under which the convicted person faces a very heavy burden in terms of raising doubts about his guilt. Herrera, 506 U.S. at 417, 113 S.Ct. 853. The lower court’s reliance on Herrera raises the question of whether the court erroneously placed the burden on appellant to raise doubts about his guilt. Although the lower court does not need the reminder of a presumption of innocence in order to perform its Article 66(c), UCMJ, review, we must be assured on appeal that the court did not improperly shift the burden to appellant to raise doubts about his guilt, which would indicate “application of an erroneous principle of law.” Troutt, 8 USCMA at 439, 24 CMR at 249. A limited remand is appropriate in the present case to ensure that the court below has applied the correct principles of law. See United States v. Hutchison, 57 MJ 231 (2002).
III. REVIEW OF APPELLANT’S SENTENCE BY THE COURT OF CRIMINAL APPEALS
Before the Court of Criminal Appeals, appellant introduced information concerning the disposition of other anthrax-related cases in the Air Force. The information indicated that disciplinary action had been taken in “just over 150 Air Force cases” involving refusal to take the anthrax vaccine. Some of the cases involved repeat offenders. Of the six individuals whose cases were referred to summary courts-martial, all eventually were given an administrative discharge. One of the six cases was referred to a special court-martial after the accused objected to a summary court-martial under Article 20, UCMJ, 10 USC § 820, and he subsequently requested and was granted an administrative discharge in lieu of court-martial. One officer, who was offered nonjudieial punishment under Article 15, UCMJ, requested trial by court-martial, and his case was pending at the time appellant’s case was under review at the Court of Criminal Appeals. See 54 MJ at 942-43.
The Court of Criminal Appeals identified specific aspects of appellant’s case which it viewed as significant on the issue of sentence appropriateness, including a letter of counseling for reporting late for duty, a letter of reprimand for similar misconduct on a different date and for insubordinate conduct towards a noncommissioned officer, and negative comments in the performance report he received prior to deployment. Id. at 943. The court also took note of “substantial evidence that ... appellant was motivated to refuse the inoculation, not because of his concern for the effects of the vaccine upon his body, but because he wanted to return to Barksdale Air Force Base to operate a trucking business he had been running during his off-duty hours before he deployed.” Id. The court, noting that it had considered “all the facts and circumstances surrounding the commission of the offense, as well as the character of ... appellant and the matters in the record of trial,” concluded that the sentence was appropriate. Id.
*401In the present appeal, appellant contends that the lower court abused its discretion by not granting relief on the basis of sentence appropriateness. Appellant does not contend in this appeal that he is the subject of discriminatory or selective prosecution. Compare United States v. Garwood, 20 MJ 148, 154 (CMA 1985).
The information submitted by appellant to the Court of Criminal Appeals reflects a variety of discretionary dispositions by Air Force commanders over both a relatively brief period of time and a small number of cases. In reviewing a case for sentence appropriateness, the Courts of Criminal Appeals are not required to compare appellant’s case to other specific cases unless the appellant demonstrates that his or her case is closely related to the case or cases offered for comparison. The mere similarity of offenses is not sufficient. See United States v. Wacha, 55 MJ 266, 267-68 (2001).
In our review of sentence appropriateness decisions by the Courts of Criminal Appeals, we determine whether the lower court “abused its discretion or caused a miscarriage of justice” in exercising its highly discretionary sentence review function. Id. at 268 (citing United States v. Fee, 50 MJ 290, 291 (1999)). In the present case, the court below considered both the data provided by appellant and the specific circumstances of appellant’s case. The court’s delineation of the factors pertinent to its exercise of this highly discretionary function did not constitute either an abuse of discretion or a miscarriage of justice.
IV. CONCLUSION
The decision of the United States Air Force Court of Criminal Appeals is set aside. The record of trial is returned to the Judge Advocate General of the Air Force for remand to the Court of Criminal Appeals for further consideration of Issue II in accordance with this opinion. Thereafter, the record of trial shall be returned directly to this Court.
All Manual provisions cited are identical to those in effect at the time of appellant’s court-martial.