Under Article 51 of the Charter of the United Nations (Charter), states possess an inherent right to exercise self-defence against armed attacks. At the level of principle, the rationale of Article 51 seems hard (if not impossible) to dispute, yet the provision has prompted much discussion, both in the literature and in practice. In particular, recent years have witnessed renewed debates about the temporal and material requirements of Article 51. Faced with assertions of a right to exercise preventive self-defence, culminating in the Bush Doctrine of autumn 2002, a majority of states has confirmed that self-defence could only be lawful if exercised against attacks that are either ongoing or imminent. As regards the material element, the International Court of Justice (ICJ), in its Oil Platforms Case of December 2003, affirmed that self-defence could only be used against military attacks of a qualified nature; hence its distinction between armed attacks in the sense of Article 51 and lesser forms of force not triggering a right of self-defense.
The present note is concerned with the issue of the identity of the attacker. Undoubtedly, self-defence is available against state attacks. However, whether it should also be available against non-state attacks is much discussed.