Can Non-State Actors Mount an Armed Attack?

Abstract

Article 2(4) of the United Nations (Charter prohibits the use of force between States, but that prohibition does not “impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations”. In its Charter incarnation, the prohibition of the use of force is situated in a strictly inter-State context, and does not speak to the phenomenon of uses of force by Non-State Actors (‘NSAs’). The question examined in this Chapter is whether the exception to that prohibition – the right to use force in self-defence – is nevertheless responsive to the war-making capacity of NSAs or whether it is limited to a snapshot of the right as it may have been conceptualised in the immediate aftermath of a global conflict between States. Otherwise put, is the definition of ‘armed attack’ in Article 51 of the UN Charter (and related customary international law) conditioned on the attacker being a State?