109 / 532
93
THE DEFINITION OF AGGRESSION AND THE USE OF FORCE
act of aggression for the Kampala “crime of aggression” is given in Art. 8 bis (1) “by
its character, gravity and scale” which “constitutes a manifest violation of the Charter
of the United Nations”. These general notions of character, gravity, scale or manifest
violation may lead in some cases to a different, rather subjective interpretation of
these terms. This is mainly a problem for the decision- making of the ICC itself.
On the other hand, the decisions of the ICC will have impact on the understanding
of aggression as prohibited in the
jus ad bellum
. It would be useful to specify the
customary international law prohibiting aggression and to analyze the differences
with regard to the Kampala definition in international law. Different opinions were
expressed as to if Art. 5 (1) of the 1974 Definition of aggression confirms existing
international customary law.
87
This definition was centred on state responsibility for
acts of aggression and not on the criminal responsibility of individuals. The Kampala
definition of the crime of aggression was designed predominantly as a judicial
definition for the ICC. Serious concern has been expressed that this definition may
do harm to the
jus ad bellum
definition of aggression. In M. O’Connel’s view, there
are now two competing definitions of aggression in public international law, and it
is perceived that the Kampala definition departs from the customary law crime of
aggression and the
jus ad bellum
definition of aggression.
88
The concern about the
future impact of the Kampala definition on the
jus ad bellum
definition of aggression
seems to be justified. It will also depend on the effectivity of the ICC jurisdiction
in prosecuting crimes of aggression which may substantially affect the
jus ad bellum
understanding of aggression.
87
Dinstein, Y.,
supra
note 1, p. 135.
88
O’Connell, M.,
supra
note 49.