CYIL Vol. 5, 2014

JOSEF MRÁZEK

CYIL 5 ȍ2014Ȏ

5. Conclusions The study illustrates the enormous difficulties in attempts to define “aggression” since the League of Nations period. Art. 2 (4) of the UN Charter is the basis of any definition of aggression in contemporary international law. Not every unlawful use of armed force necessarily equates to an “act of aggression”. The problem of the definition was always a matter of great controversy. After the 2010 Kampala definition of the crime of aggression we have, together with the 1974 Definition of Aggression, in fact two, somewhat competing definitions on the same subject. Only a serious and large scale violation of Art. 2 (4) of the UN Charter amounts to aggression. Already in the Preamble to the 1974 Definition of Aggression the view was expressed that “aggression is the most serious and dangerous form of the illegal use of force”. This 1974 Definition aimed to prevent states from the perpetration of aggression. The purpose of the Kampala 2010 definition is the individual criminal responsibility of political and military leaders. So far it is premature to consider all the consequences of these “bipolar” definitions – for prohibition of the use of force and for successful prosecution of “crimes of aggression”. It is open to question which contribution the Kampala definition will have for strengthening the jus ad bellum prohibition of the use of armed force (aggression) without proper support of the Great Powers. The crime of aggression included in the ICC Statute differs from the 1974 Definition and in some way may weaken the threshold of occurrence not only for crimes of aggression but for all “acts of aggression” in general. It is difficult to predict the results of intended ICC prosecution for crimes of aggression, but ICC jurisdiction may perhaps be the decisive first step in this direction. At the Kampala Review Conference a package of amendments on the crime of aggression was adopted by consensus. The definition of the crime of aggression limits criminal responsibility to responsible leaders, and ICC jurisdiction is based on UNSC referral or state consent. Non-state parties are excluded from ICC jurisdiction. The crime of aggression concerning individual criminal liability was in fact opposed to the definition of an “act of aggression” of the state. Both notions are of course closely interconnected. To exclude minor incidents acts of aggression must by its “character, gravity and scale” constitute a “manifest violation” of the UN Charter. At least eighty- four states parties to the Rome Statute participating at the Kampala Conference view the adoption of the definition of the crime of aggression as a success. Originally, the inclusion of the crime of aggression in the ICC was controversial. The Kampala definition of the crime of aggression is rather narrow. The 1974 Definition of Aggression lists acts of aggression in Art. 3 constituting the general notion of “aggression”, depending on the discretionary power and determination of the UNSC, which may decide that, due to relevant circumstances or their consequences, aggression did not occur. It is not clear whether the acts contained e.g. in letters (c), (e) and (f ) will reach the threshold required for the crime of aggression. Besides, the list of aggression is not deemed to be exhaustive. Every act of aggression must fall within Art. 8 bis (2) of the ICC Statute. The threshold of an

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