CYIL Vol. 6, 2015

THE DEFINITION OF THE CRIME OF AGGRESSION… to opt-into the system [by ratification or acceptance of the aggression amendments], because under article 12(1), it already accepted the Court’s jurisdiction over the crime of aggression”; 26 and he adds that “if the negative understanding of the second sentence of article 121(5) held up, it would pull the rug from underneath the concept of an opt-out system; instead, it would be an ‘opt-in-then-opt-out’ system, which defies the logic of the negotiations at the Review Conference”. 27 In other words, the opt-out system established by article 15bis(4) would lose its raison d’etre , since, under the positive understanding, this provision is practically relevant only for States Parties which have not ratified (accepted) the aggression amendments but are already subjected, under article 12(1), to the jurisdiction of the Court over the crime of aggression. 28 However, as pointed out by Robert Heinsch, “[w]hile this kind of provision [article 15bis(4)] would have made sense in case the amendment procedure was to be determined by Article 121(4), and then a State which is belonging to the minority that did not ratify the amendment had a chance to exclude the jurisdiction over its nationals, this argument prima facie can not be raised now that States Parties have settled for the Article 121(5) procedure. According to the second sentence of this provision, it is clear that [i]n respect of a State Party which has not accepted the amendment, the Court shall not exercise its jurisdiction regarding a crime covered by the amendment.”. 29 Unlike supporters of the negative understanding of article 121(5), second sentence, the proponents of positive understanding have to deal with the following additional question: do any of the States Parties involved in the crime of aggression, i.e. an aggressor State Party and/or a victim State Party, have to ratify the aggression amendments to enable the Court to exercise its jurisdiction over the crime of aggression, and if so, which of them? None of them, one of them, both of them? It is suggested that, under the positive understanding taken to its logical conclusion, the Court should be entitled [after its jurisdiction is activated in accordance with article 15(bis)(2) and (3)] to exercise its jurisdiction over the crime of aggression in regard to all States Parties, 26 Stefan Barriga, op. cit. sub 1, p. 46. 27 Stefan Barriga, op. cit. sub 1, pp. 47 and 51. 28 In addition, the logic of the opt-out declaration is questionable also in a situation when it is lodged by a State Party which ratified or accepted the aggression amendments. In this case, such a State Party would, under the positive understanding, just help reach the required number (thirty) of ratifications and, in addition, would be under the protection of the Court’s jurisdiction with regard to an act (crime) of aggression committed against it by (nationals of) another State Party (whether or not the other State Party ratified or accepted the aggression amendments), but would, at the same time, “cunningly” evade the Court’s jurisdiction over the possible crime of aggression committed by itself againt another State Party! See also Marko Milanović, op. cit. sub 16, p. 180. (“This simply creates a perverse incentive, without any principled justification … – a state party which opts out is protected by threat of criminal prosecutions from aggression by other states, while its own nationals are not exposed to any such risk”); and Milan Lipovský, op. cit. sub 12, pp. 88-89. 29 Robert Heinsch, The Crime of Aggression After Kampala: Success or Burden for the Future?, Goettingen Journal of International Law 2 (2010) 2, p. 738.

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