19. For the reasons set out in the Joint Separate Opinion of Judge McDonald and Judge Vohrah and in the Separate and Dissenting Opinion of Judge Li, the majority of the Appeals Chamber finds that duress does not afford a complete defence to a soldier charged with a crime against humanity and/or a war crime involving the killing of innocent human beings. 

The Joint Separate Opinion of Judge McDonald and Judge Vohrah sets out the reasons as follows:

34. Superior orders and duress are conceptually distinct and separate issues and often the same factual circumstances engage both notions, particularly in armed conflict situations.  We subscribe to the view that obedience to superior orders does not amount to a defence per se but is a factual element which may be taken into consideration in conjunction with other circumstances of the case in assessing whether the defences of duress or mistake of fact are made out.

35. […] As obedience to superior orders may be considered merely as a factual element in determining whether duress is made out on the facts, the absence of a superior order does not mean that duress as a defence must fail.

36. […] [W]e would like to reiterate our view that obedience to superior orders is merely a factual circumstance to be considered when determining whether the defence of duress is made out on the merits.  The fact that the Appellant obeyed an order of a superior does not go to the preceding legal question of whether duress may at all be pleaded as a defence.

In order to decide on the international customary law nature of duress as a defence to the killing of innocent persons, the Joint Separate Opinion of Judge McDonald and Judge Vohrah carried out a review of the case-law, state practice and opinio juris in paragraphs 41 to 49 of their Joint Opinion and concluded:

50. Not only is State practice on the question as to whether duress is a defence to murder far from consistent, this practice of States is not, in our view, underpinned by opinio juris.  Again to the extent that state practice on the question of duress as a defence to murder may be evidenced by the opinions on this question in decisions of national military tribunals and national laws, we find quite unacceptable any proposition that States adopt this practice because they “feel that they are conforming to what amounts to a legal obligation” at an international level[1].

55. In light of the above discussion, it is our considered view that no rule may be found in customary international law regarding the availability or the non-availability of duress as a defence to a charge of killing innocent human beings.  The post-World War Two military tribunals did not establish such a rule.  We do not think that the decisions of these tribunals or those of other national courts and military tribunals constitute consistent and uniform state practice underpinned by opinio juris sive necessitatis.

The Joint Separate Opinion of Judge McDonald and Judge Vohrah then analysed the general principles of law recognised by civilised nations in order to shed light to the issue of duress in paragraphs 56 to 65 and concluded that:

66.        Having regard to the above survey relating to the treatment of duress in the various legal systems, it is, in our view, a general principle of law recognised by civilised nations that an accused person is less blameworthy and less deserving of the full punishment when he performs a certain prohibited act under duress.  We would use the term “duress” in this context to mean “imminent threats to the life of an accused if he refuses to commit a crime” and do not refer to the legal terms of art which have the equivalent meaning of the English word “duress” in the languages of most civil law systems.  This alleviation of blameworthiness is manifest in the different rules with differing content in the principal legal systems of the world as the above survey reveals.  On the one hand, a large number of jurisdictions recognise duress as a complete defence absolving the accused from all criminal responsibility. On the other hand, in other jurisdictions, duress does not afford a complete defence to offences generally but serves merely as a factor which would mitigate the punishment to be imposed on a convicted person.  Mitigation is also relevant in two other respects.  Firstly, punishment may be mitigated in respect of offences which have been specifically excepted from the operation of the defence of duress by the legislatures of some jurisdictions.  Secondly, courts have the power to mitigate sentences where the strict elements of a defence of duress are not made out on the facts.

It is only when national legislatures have prescribed a mandatory life sentence or death penalty for particular offences that no consideration is given in national legal systems to the general principle that a person who commits a crime under duress is less blameworthy and less deserving of the full punishment in respect of that particular offence.

67.        The rules of the various legal systems of the world are, however, largely inconsistent regarding the specific question whether duress affords a complete defence to a combatant charged with a war crime or a crime against humanity involving the killing of innocent persons.  As the general provisions of the numerous penal codes set out above show, the civil law systems in general would theoretically allow duress as a complete defence to all crimes including murder and unlawful killing.  On the other hand, there are laws of other legal systems which categorically reject duress as a defence to murder.   Firstly, specific laws relating to war crimes in Norway and Poland do not allow duress to operate as a complete defence but permit it to be taken into account only in mitigation of punishment.  Secondly, the Ethiopian Penal Code of 1957 provides in Article 67 that only “absolute physical coercion” may constitute a complete defence to crimes in general.  Where the coercion is “moral”, which we would interpret as referring to duress by threats, the accused is only entitled to a reduction of penalty.  This reduction of penalty may extend, where appropriate, even to a complete discharge of the offender from punishment.  Thirdly,  the common law systems throughout the world, with the exception of a small minority of jurisdictions of the United States which have adopted without reservation Section 2.09 of the United States Model Penal Code, reject duress as a defence to the killing of innocent persons. 

72. It is clear from the differing positions of the principal legal systems of the world that there is no consistent concrete rule which answers the question whether or not duress is a defence to the killing of innocent persons.  It is not possible to reconcile the opposing positions and, indeed, we do not believe that the issue should be reduced to a contest between common law and civil law. We would therefore approach this problem bearing in mind the specific context in which the International Tribunal was established, the types of crimes over which it has jurisdiction, and the fact that the International Tribunal’s mandate is expressed in the Statute as being in relation to “serious violations of international humanitarian law”.

See also paragraphs 68–71.

After concluding that it is not possible to reconcile the opposing positions of the principal legal systems of the world on the question whether or not duress is a defence to the killing of innocent persons, Judge McDonald and Judge Vohrah held:

72. […] We would therefore approach this problem bearing in mind the specific context in which the International Tribunal was established, the types of crimes over which it has jurisdiction, and the fact that the International Tribunal’s mandate is expressed in the Statute as being in relation to “serious violations of international humanitarian law”.

75. […] The purview of the International Tribunal relates to war crimes and crimes against humanity committed in armed conflicts of extreme violence with egregious dimensions.  We are not concerned with the actions of domestic terrorists, gang-leaders and kidnappers.  We are concerned that, in relation to the most heinous crimes known to humankind, the principles of law to which we give credence have the appropriate normative effect upon soldiers bearing weapons of destruction and upon the commanders who control them in armed conflict situations.  The facts of this particular case, for example, involved the cold-blooded slaughter of 1200 men and boys by soldiers using automatic weapons.  We must bear in mind that we are operating in the realm of international humanitarian law which has, as one of its prime objectives, the protection of the weak and vulnerable in such a situation where their lives and security are endangered. Concerns about the harm which could arise from admitting duress as a defence to murder were sufficient to persuade a majority of the House of Lords and the Privy Council to categorically deny the defence in the national context to prevent the growth of domestic crime and the impunity of miscreants.  Are they now insufficient to persuade us to similarly reject duress as a complete defence in our application of laws designed to take account of humanitarian concerns in the  arena of brutal war, to punish perpetrators of crimes against humanity and war crimes, and to deter the commission of such crimes in the future?   If national law denies recognition of duress as a defence in respect of the killing of innocent persons, international criminal law can do no less than match that policy since it deals with murders often of far greater magnitude.  If national law denies duress as a defence even in a case in which a single innocent life is extinguished due to action under duress, international law, in our view, cannot admit duress in cases which involve the slaugher of innocent human beings on a large scale.  It must be our concern to facilitate the development and effectiveness of international humanitarian law and to promote its aims and application by recognising the normative effect which criminal law should have upon those subject to them.  Indeed, Security Council resolution 827 (1993) establishes the International Tribunal expressly as a measure to “halt and effectively redress” the widespread and flagrant violations of international humanitarian law occurring in the territory of the former Yugoslavia and to contribute thereby to the restoration and maintenance of peace.

80. […] The approach we take does not involve a balancing of harms for and against killing but rests upon an application in the context of international humanitarian law of the rule that duress does not justify or excuse the killing of an innocent person.  Our view is based upon a recognition that international humanitarian law should guide the conduct of combatants and their commanders.  There must be legal limits as to the conduct of combatants and their commanders in armed conflict.  In accordance with the spirit of international humanitarian law, we deny the availability of duress as a complete defence to combatants who have killed innocent persons.  In so doing, we give notice in no uncertain terms that those who kill innocent persons will not be able to take advantage of duress as a defence and thus get away with impunity for their criminal acts in the taking of innocent lives.

88. After the above survey of authorities in the different systems of law and exploration of the various policy considerations which we must bear in mind, we take the view that duress cannot afford a complete defence to a soldier charged with crimes against humanity or war crimes in international law involving the taking of innocent lives.  We do so having regard to our mandated obligation under the Statute to ensure that international humanitarian law, which is concerned with the protection of humankind, is not in any way undermined.

See also paras. 73-74, 75 (part not cited above), 76-79, 80 (part not cited above), 81-87.

In his Separate and Dissenting Opinion Judge Li stated the following:

5. From a study of decisions [of the United States Military Tribunals at Nürnberg in proceedings under the Control Council Law No. 10 and those of Military Tribunals and/or Courts set up by various other allied countries for the same purpose for the same purpose] the following principles can be obtained:  as a general rule, duress can be a complete defence if the following requirements are met, (a) the act was done to avoid an immediate danger both serious and irreparable, (b) there was no other adequate means to escape, and (c) the remedy was not disproportionate to evil.  To this general rule there is an important exception:  if the act was a heinous crime, for instance, the killing of innocent civilians or prisoners of war, duress cannot be a complete defence, but can only be a ground of mitigation of punishment if justice requires.

8. In my view, both the rule and the exception are reasonable and sound, and should be applied by this International Tribunal. However, as this appeal case is concerned with the applicability of the exception, a few more words should be said about it.

In the first place, the main aim of international humanitarian law is the protection of innocent civilians, prisoners of war and other persons hors de combat.  As the life of an innocent human being is the sine qua non of his existence, so international humanitarian law must strive to ensure its protection and to deter its destruction.  Admission of duress as a complete defence or justification in the massacre of innocent persons is tantamount to both encouraging the subordinate under duress to kill such persons with impunity instead of deterring him from committing such a horrendous crime, and also helping the superior in his attempt to kill them.  Such an anti-human policy of law the international community can never tolerate, and this International Tribunal can never adopt.

Second, the present municipal laws of various countries regarding the propriety or necessity of recognising the exception to the rule, as shown above, are divergent.  On the one hand, the legal systems of the British Commonwealth and some civil-law systems admit the exception.  On the other hand, some other civil-law systems do not provide for it.  In such circumstances, this International Tribunal cannot but opt for the solution best suited for the protection of innocent persons.

See also paras. 3-4, 6-7 and 9-10 of the Separate and Dissenting Opinion of Judge Li.

18. The Appeals Chamber, for the reasons set out in the Joint Separate Opinion of Judge McDonald and Judge Vohrah, unanimously finds that the Appellant’s plea was voluntary.

19. […] [T]he majority of the Appeals Chamber finds that the guilty plea of the Appellant was not equivocal. […]

20. […] The Appeals Chamber, for the reasons set out in the Joint Separate Opinion of Judge McDonald and Judge Vohrah, finds that the guilty plea of the Appellant was not informed and accordingly remits the case to a Trial Chamber other than the one which sentenced the Appellant in order that he be given an opportunity to replead. […]

The Joint Separate Opinion of Judge McDonald and Judge Vohrah found that for a guilty plea to be entered, certain pre-conditions must be satisfied:

 8. […]  It follows, therefore, that certain pre-conditions must be satisfied before a plea of guilty can be entered. In our view, the minimum  re-conditions are as follows:

a)     The guilty plea must be voluntary.  It must be made by an accused who is mentally fit to understand the consequences of pleading guilty and who is not affected by any threats, inducements or promises.

b)     The guilty plea must be informed, that is, the accused must understand the nature of the charges against him and the consequences of pleading guilty to them.  The accused must know to what he is pleading guilty;

c)     The guilty plea must not be equivocal.  It must not be accompanied by words amounting to a defence contradicting an admission of criminal responsibility;

10. […] Voluntariness involves two elements.  Firstly, an accused person must have been mentally competent to understand the consequences of his actions when pleading guilty.  […] Secondly, the plea must not have been the result of any threat or inducement other than the expectation of receiving credit for a guilty plea by way of some reduction of sentence. 

13. […] Although it appears that the Appellant did not in his reply address the question whether he was promised anything for his plea, in the absence of any suggestion that the plea was improperly solicited, we would find that the Appellant pleaded guilty voluntarily whilst he was mentally competent to comprehend the consequences of his so pleading.

14. The fact that the Appellant was mentally competent to comprehend the consequences of pleading guilty does not necessarily mean that the plea was “informed”.  Indeed, all common law jurisdictions insist that an accused who pleads guilty must understand the nature and consequences of his plea and to what precisely he is pleading guilty[1].  […] In respect of the present case, an informed plea would require that the Appellant understand (a)   the nature of the charges against him and the consequences of pleading guilty generally; and (b) the nature and distinction between the alternative charges and the consequences of pleading guilty to one rather than the other.

15. […] We feel unable to hold with any confidence that the Appellant was adequately informed of the consequences of pleading guilty by the explanation offered during the initial hearing.  It was not clearly intimated to the Appellant that by pleading guilty, he would lose his right to a trial, to be considered innocent until proven guilty and to assert his innocence and his lack of criminal responsibility for the offences in any way.  It was explained to the Appellant that, if he pleaded not guilty he would have to contest the charges, whereas, if he pleaded guilty he would be given the opportunity of explaining the circumstances under which the offence was committed.

16.        Moreover, it appears to us that defence counsel consistently advanced arguments contradicting the admission of guilt and criminal responsibility implicit in a guilty plea.  If the defence had truly understood the nature of a guilty plea, it would not have persisted in its arguments which were obviously at odds with such a plea. […]  

19. […] With respect, the difference between a crime against humanity and a war crime was not adequately explained to the Appellant by the Trial Chamber at the initial hearing nor was there any attempt to explain the difference to him at any later occasion when the Appellant reaffirmed his plea.  […]

We have, accordingly, no doubt that the misapprehension regarding the true distinction between the two alternative charges led the Appellant to plead guilty to the more serious of the two charges, that is, the charge alleging the crime against humanity. 

26. […] There is nothing on the record to show that anyone, either defence counsel or the Trial Chamber, had explained to the Appellant that a crime against humanity is a more serious crime and that if he had pleaded guilty to the alternative charge of a war crime he could expect a correspondingly lighter punishment. […]

31. Whether a plea of guilty is equivocal must depend on a consideration, in limine, of the question whether the plea was accompanied or qualified by words describing facts which establish a defence in law.  The Appellant pleaded guilty but claimed that he acted under duress.  It follows therefore that we must now examine whether duress can constitute a complete defence to the killing of innocent persons.

70. [A]n armed conflict exists whenever there is a resort to armed force between States or protracted armed violence between governmental authorities and organized armed groups or between such groups within a State. International humanitarian law applies from the initiation of such armed conflicts and extends beyond the cessation of hostilities until a general conclusion of peace is reached; or, in the case of internal conflicts, a peaceful settlement is achieved. Until that moment, international humanitarian law continues to apply in the whole territory of the warring States or, in the case of internal conflicts, the whole territory under the control of a party, whether or not actual combat takes place there. […]

141. It is by now a settled rule of customary international law that crimes against humanity do not require a connection to international armed conflict. Indeed, as the Prosecutor points out, customary international law may not require a connection between crimes against humanity and any conflict at all. Thus, by requiring that crimes against humanity be committed in either internal or international armed conflict, the Security Council may have defined the crime in Article 5 [of the ICTY Statute] more narrowly than necessary under customary international law. There is no question, however, that the definition of crimes against humanity adopted by the Security Council in Article 5 comports with the principle of nullum crimen sine lege.

142. We conclude, therefore, that Article 5 may be invoked as a basis of jurisdiction over crimes committed in either internal or international armed conflicts. […]

24. The doctrines of "political questions" and "non-justiciable disputes" are remnants of the reservations of "sovereignty", "national honour", etc. in very old arbitration treaties. They have receded from the horizon of contemporary international law, except for the occasional invocation of the "political question" argument before the International Court of Justice in advisory proceedings and, very rarely, in contentious proceedings as well. […]

25. The Appeals Chamber does not consider that the International Tribunal is barred from examination of the Defence jurisdictional plea by the so-called "political" or "non-justiciable" nature of the issue it raises.

6. This narrow interpretation of the concept of jurisdiction, which has been advocated by the Prosecutor and one amicus curiae, falls foul of a modern vision of the administration of justice. Such a fundamental matter as the jurisdiction of the International Tribunal should not be kept for decision at the end of a potentially lengthy, emotional and expensive trial. All the grounds of contestation relied upon by Appellant result, in final analysis, in an assessment of the legal capability of the International Tribunal to try his case. What is this, if not in the end a question of jurisdiction? And what body is legally authorized to pass on that issue, if not the Appeals Chamber of the International Tribunal? Indeed - this is by no means conclusive, but interesting nevertheless: were not those questions to be dealt with in limine litis, they could obviously be raised on an appeal on the merits. Would the higher interest of justice be served by a decision in favour of the accused, after the latter had undergone what would then have to be branded as an unwarranted trial. After all, in a court of law, common sense ought to be honoured not only when facts are weighed, but equally when laws are surveyed and the proper rule is selected. In the present case, the jurisdiction of this Chamber to hear and dispose of Appellant's interlocutory appeal is indisputable.

59. The principle of primacy of this International Tribunal over national courts must be affirmed; the more so since it is confined within the strict limits of Articles 9 and 10 of the Statute and Rules 9 and 10 of the Rules of Procedure of the International Tribunal. […]

See also para. 58.

36. […] In sum, the establishment of the International Tribunal falls squarely within the powers of the Security Council under Article 41.

See also paras 31, 38.

134. […] [C]ustomary international law imposes criminal liability for serious violations of common Article 3 [of the Geneva Conventions of 1949], as supplemented by other general principles and rules on the protection of victims of internal armed conflict, and for breaching certain fundamental principles and rules regarding means and methods of combat in civil strife.

94. […] The following requirements must be met for an offence to be subject to prosecution before the International Tribunal under Article 3 [of the ICTY Statute]:

(i) the violation must constitute an infringement of a rule of international humanitarian law;

(ii) the rule must be customary in nature or, if it belongs to treaty law, the required conditions must be met (see below, para. 143);

(iii) the violation must be "serious", that is to say, it must constitute a breach of a rule protecting important values, and the breach must involve grave consequences for the victim. Thus, for instance, the fact of a combatant simply appropriating a loaf of bread in an occupied village would not amount to a "serious violation of international humanitarian law" although it may be regarded as falling foul of the basic principle laid down in Article 46, paragraph 1, of the Hague Regulations (and the corresponding rule of customary international law) whereby "private property must be respected" by any army occupying an enemy territory;

(iv) the violation of the rule must entail, under customary or conventional law, the individual criminal responsibility of the person breaching the rule.

It follows that it does not matter whether the "serious violation" has occurred within the context of an international or an internal armed conflict, as long as the requirements set out above are met.