CYIL 2014

THE DEFINITION OF AGGRESSION AND THE USE OF FORCE

Questions of motive and intent were discussed e.g. by the drafting of the

1974 Definition of Aggression. There was deep disagreement on the role of

animus

aggressionis

in the drafting of the Definition of Aggression. The ICJ in the Nicaragua

case left the questions of motive and intents aside in its reflections. Pursuant to A.

Cassese it would be a mistake to believe that, without an exhaustive definition of

aggression, (his Article was written before 2010) Kampala definition perpetrators of

this crime may not be prosecuted and punished. He observed that some traditional

forms of aggression are prohibited by customary international law and that customary

norms are basically those envisaged by the 1974 Declaration. The ICJ in the 1986

Nicaragua case confirmed that Art. 3(g) reflected customary international law.

The

ICJ in the Barcelona Traction case stated that the principles of international law

outlawing acts of aggression are obligations

erga omnes.

The concept of

erga omnes

obligations expressed by the Court was generally endorsed by the ILC and applied

to the breach of international obligations which constituted “international crimes”.

3.5 The Relationship between “Act of Aggression”, “Armed Attack” and

“Armed Intervention” – Additional Remarks

In Art. 51 and 39 of the UN Charter two different notions are contained: “armed

attack” and “act of aggression”. For purposes of self-defense the term of “armed

attack” was preferred in Art. 51 over the term of “aggression”. Nevertheless, in the

also authentic French version of the UN Charter the term “armed attack” is not

expressed as

“attaque armée”

but as

“aggression armée”

, which may indicate that the

original French thinking was in favour of the identity of both terms(?!). Neither the

notions of “armed attack” nor of “aggression” were defined during the UN Charter

preparation.

The ICJ in the Nicaragua case considered what constituted an armed attack.

The sending of armed bands in the Court’s opinion constitutes an armed attack

provided the classified “scale and effects”. The 1974 Definition of Aggression gave

the same guidance to any reasonable interpretation. The decisive features mentioned

by the ICJ were “the scale and effects” of the use of force and, in second place,

the circumstances and motivations of the attack.

This is a subjective appreciation

which might be, of course, rather controversial. The Court was sharply criticised for

its narrow view of armed attacks, mainly by American representatives and lawyers,

for consequent limitation of the U.S. right to collective self-defense.

Y. Dinstein

asserted that there is no cause to remove small scale armed attacks from the spectrum

ICJ Reports, Judgements of 27 June 1986 Case concerning military and paramilitary activities in and

against Nicaragua,14, para. 195.

See Barcelona Traction Light and Power Company Ltd. Judgement, 1970 I.C.J., p. 32.

ICJ Reports, Judgements of 27 June,

supra

note 60, para. 195 and 231.

Hargrove, J. L., The Nicaragua Judgment and the Future of the Law of Force and Self-defence,

AJIL

1987, No. 1, p. 135.