Prosecuting the Crime of Aggression in the International Criminal Court

The crime of aggression was included in the subject-matter jurisdiction of the International Criminal Court (ICC) (Article 5(1)(d) of the ICC Statute), but the competence of the ICC to prosecute aggression was made subject to the adoption of a definition of the crime and of the circumstances under which the ICC could exercise jurisdiction (Article 5(2)). Following years of intensive deliberations, the matter was finally settled by a Review Conference of the International Criminal Court that was held in Kampala, Uganda on May 31 through June 11, 2010.The crime of aggression committed by an individual is based on an act of aggression committed by a State. The definition of an act of aggression approved by general agreement in Kampala simply repeats the provisions of General Assembly Resolution 3314 (XXIX) of December 14, 1974, that was initially designed as a guide for the Security Council when exercising its Chapter VII powers to counteract a threat to the peace, a breach of the peace, or an act of aggression. The crime of aggression was defined in Kampala, again by general agreement, as “the planning, preparation, initiation or execution, by a person in a position effectively to exercise control over or to direct the political or military action which, by its character, gravity and scale, constitutes a manifest violation of the Charter of the United Nations.” The crime of aggression thus came to be defined as (a) a leadership crime; (b) flowing forth from an act of aggression; and (c) subject to U.N. Charter constraints. The definition furthermore followed the “differentiated approach” whereby the means of perpetration and the element of mens rea are not included in the definition but are dealt with separately in other sections of the ICC Statute (Articles 25(3) and 30, respectively). In virtue of the fact that aggression is a leadership crime, perpetration as an accessory (Article 25(3)(c)), attempt to commit the crime (Article 25(3)(d)), and vicarious liability for a crime committed by others (Article 28), will not be feasible in cases of aggression.More difficult, though, was reaching general agreement on the circumstances under which the ICC can prosecute the crime of aggression; in particular the role to be afforded to the Security Council. It was decided in Kampala to deal separately with instances where investigations were triggered by State Party referrals or by the Prosecutor acting proprio motu on the one hand (Article 15bis), and by a Security Council referral on the other (Article 15ter). In the case of State Party referrals and investigations proprio motu, the Prosecutor must first establish whether the Security Council has made a determination of an act of aggression. If it has, the Prosecutor may proceed with the investigation; if it has not done so within a period of six months after having been notified by the Prosecutor, a Pre-Trial Chamber of the ICC may authorize the investigation to proceed. In the case of Security Council referrals, the Prosecutor may proceed with an investigation into the commission of the crime of aggression without further ado. In both instances, a determination of an act of aggression by the Security Council is not binding to the ICC’s own finding in this regard.In the case of State Party referrals and investigations proprio motu, the crime of aggression cannot be prosecuted in the ICC (a) if the State guilty of the act of aggression is not a State Party to the ICC Statute, in which event the ICC cannot exercise its jurisdiction over the crime of aggression committed by a national or on the territory on the non-party State; or (b) if the State concerned, being a State Party, has submitted a prior declaration to the Registrar of the ICC that it does not accept the jurisdiction of the ICC over the crime of aggression. These constraints do not apply in the case of Security Council referrals.The amendments to the ICC Statute approved by the Review Conference will enter into force following ratification of the amendments by no less than thirty States Parties. Furthermore, implementation of the decisions taken in Kampala in respect of the crime of aggression will be kept on ice until at least January 1, 2017, after which a decision to implement the same must again be approved by the same majority of States Parties required for amendments of the ICC Statute. Although this outcome is in a sense disappointing, the fact that nations of the world have now agreed on a definition of aggression will most likely serve as a deterrent against unbecoming military action by trigger-happy regimes.