CYIL 2015

AGGRESSION ȃ THE SUPREME INTERNATIONAL CRIME OR NOT A CRIME AT ALL?

and the number of relevant trials at the domestic or international level should be

taken into account.

This, however, brings us back to the history and morality

argument. Overall, Bassiouni´s definition(s) of international crimes are somewhat

confusing as they put together the elements of such crimes, the characteristic of the

categories from which potential candidates for this qualification come, as well as the

legal implication of the qualification.

The concept of international crime or crime under international law has not so

far secured a uniformly accepted definition. Its absence obviously makes it uneasy to

determine whether a certain act – for instance aggression – qualifies as an international

crime or not. Yet, despite the lack of a definition, there seems to be at least a tentative

consensus on some of the elements that an international crime should reveal. Such

elements first came out during the post-WWII trials, when the defence challenged the

jurisdiction

ratione materiae

of the two international tribunals. In 1995, they were

largely confirmed in the ICTY Decision quoted above. And even more recently, they

got support at the Rome and Kampala Diplomatic Conferences: although no general

debate about international crimes took place, states were referring to similar elements

when qualifying certain acts as such (or when denying the qualification). Under these

elements, an act cannot become an international crime unless: it has a legal basis in

a rule of international law; this rule protects important universal values; this rule is

specific and clear (especially as far as the definition of the crime is concerned); and

the rule entails individual criminal responsibility. The elements are cumulative and

have to be present at the same time.

3.2 The Concept of International Crime and the Crime of Aggression

There can little doubt that genocide, crimes against humanity and war crimes

exhibit the four elements listed at the end of the previous subsection. This paper

argues that, at the current stage of development of international criminal law, the

same applies, despite some of its particularities, to the crime of aggression. The first

two elements do not seem to give rise to serious contentions. The prohibition of

aggression certainly has a legal basis in the rules of international law and this rule

protects important universal values. It is more controversial whether the rule entails

individual criminal responsibility and whether it is specific enough (i.e. whether

there is a generally accepted definition of a crime of aggression).

Aggression was to be

outlawed

at the international level as early as in 1923, when

the draft Treaty of Mutual Assistance declared that

“aggressive war is an international

crime”.

The same formulation appeared in the 1924 Protocol for the Pacific Settlement

of International Disputes and the 1927 Declaration issued by the Assembly of the

League of Nations. In 1928 in the Briand-Kellog Pact the state parties

“condemn recourse

Ibid.,

p. 70.

Cit. in

Historical Review of Developments relating to Aggression, op. cit.,

p. 30.