Prosecutor v. Erdemovic, Case No. IT-96-22 (Appeals Chamber), Joint Separate Opinion of Judge McDonald and Judge Vohrah, October 7, 1997, para. 55, 66, 72, 75, 88: The justices held 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.” In the absence of a customary rule, the justices examined “the general principles of law recognized by civilised nations” and held that there is “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,” with the term “duress” meaning “imminent threats to the life of an accused if he refuses to commit a crime.” However, the justices held that “[i]t 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.” The justices expressed concern that “in relation to the most heinous crimes known to humankind, the principles of law to which we [the ICTY] give credence have the appropriate normative effect upon soldiers bearing weapons of destruction and upon the commanders who control them in armed conflict situations,” and concluded that “international law . . . cannot admit duress in cases which involve the slaughter of innocent human beings on a large scale.” The justices held 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.” (Judge Li, in a Separate and Dissenting Opinion, concurred with Judges McDonald and Vohrah regarding the issue of duress.)
See also discussion of duress and sentencing, Section (X)(b)(iii)(4)(d), ICTY Digest.
b) Tu quoque principle rejected: the argument that the adversary committed similar crimes is not a valid defense
Kupreskic et al., (Trial Chamber), January 14, 2000, para. 51, 515-520: The argument at issue “amount[s] to saying that breaches of international humanitarian law, being committed by the enemy, justify similar breaches by a belligerent.” However, “the tu quoque defence has no place in contemporary international humanitarian law.” The Trial Chamber rejected the tu quoque principle as it is “fallacious and inapplicable” in international humanitarian law. It has been “universally rejected” and “flawed in principle” since “[i]t envisages humanitarian law as based upon a narrow bilateral exchange of rights and obligations.” Rather, “the bulk of this body of law lays down absolute obligations, namely obligations that are unconditional or in other words not based on reciprocity.”
Kordic and Cerkez, (Trial Chamber), February 26, 2001, para. 448-452: “[T]he involvement of a person in a ‘defensive operation’ does not ‘in itself’ constitute a ground for excluding criminal responsibility.”
Vasiljevic, (Trial Chamber), November 29, 2002, para. 282: “[T]he issue of diminished mental responsibility is relevant only to the sentence to be imposed. It is not a defence that if established would lead to the acquittal of the Accused.”
Mucic et al., (Appeals Chamber), February 20, 2001, para. 590: “The Appeals Chamber accepts that the relevant general principle of law upon which, in effect, both the common law and the civil law systems have acted is that the defendant’s diminished mental responsibility is relevant to the sentence to be imposed and is not a defence leading to an acquittal in the true sense.”
See also discussion of diminished mental responsibility and sentencing, Section (X)(b)(iii)(4)(f), ICTY Digest.