CYIL Vol. 6, 2015

AGGRESSION ȃ THE SUPREME INTERNATIONAL CRIME OR NOT A CRIME AT ALL? moral abhorrence at these acts; we are able to name these acts; yet we cannot really explain what makes them so specific and tells them apart from other offences. One of the first actors to try, albeit implicitly, to identify the main characteristic of an international crime was the International Criminal Tribunal for the Former Yugoslavia (hereafter the ICTY). In its 1995 decision in the Tadić Case , 43 the Appeals Chamber of the ICTY had to decide which acts counted as violations of the laws or customs of war falling under Article 3 of its Statute. It concluded that such acts had to meet four conditions: they had to constitute an infringement of a rule of international humanitarian law; the rule had to be customary in nature (or, exceptionally, conventional); the violation had to be serious, that is it had to constitute a breach of a rule protecting important values, and the breach had to involve grave consequences for the victim; and the violation had to entail the individual criminal responsibility of the person breaching the rule. 44 The conditions stricto sensu apply to war crimes only. Yet, they are not necessarily specific for them. The requirements to have a legal basis in international law, be serious in nature and entail individual criminal responsibility might be characteristic of all international crimes. This view is partly shared by international law scholars, though the writings of most of them “are uncertain, if not tenuous, as to what they deem to be the criteria justifying the establishment of crimes under international law”. 45 Yet, there are exceptions. Cassese and Gaeta, for instance, assert that international crimes result from the cumulative presence of four elements. 46 These crimes consist of violations of rules of international law; such rules are intended to protect values of the whole international community and consequently bind all states and individuals; there is a universal interest in repressing such crimes; and no functional immunity applies to the perpetrators of such crimes. 47 The first two elements are identical as under the ICTY definition. Yet, unlike the Tribunal, Cassese and Gaeta do not see individual criminal responsibility as an element of an international crime. For them, this feature stems from the nature of the violated rule, i.e. from it being intended to protect important universal values. No evidence is given in support of this claim, which, however, is far from self-evident. The third element should most probably be considered as a variation to the second one, as the universal interest in repressing a certain crime would most probably flow from its universal nature. The last element, relating to immunity, seems to be more 43 ICTY, Prosecutor v. Duško Tadić, Case No. IT-94-1-AR72, Appeals Chamber, Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction, 2 October 1995. 44 Ibid., par. 94. 45 BASSIOUNI, M. Ch.: International Crimes, op. cit., p. 132. 46 CASSESE, A., GAETA, P. (eds): Cassese´s International Criminal Law. Third Edition. Oxford University Press, Oxford, 2013, pp. 20-21. 47 The list of crimes which according to Cassese and Gaeta have these elements encompasses, in addition to the four classical crimes under international law (aggression, genocide, crimes against humanity, war crimes), also torture and international terrorism. Ibid., p. 21.

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