Self-Defence against Non-State Actors: Making Sense of the ‘Armed Attack’ Requirement

Whether States can act in self-defence against armed attacks carried out by non-State actors is one of the major debates of contemporary international law. It has relevance : the issues are significant and implicate a ‘cornerstone rule’ of the discipline, the prohibition against the use of force. 1 It has drama : ‘two main camps’ 2 are said to face each other in what is now frequently (if simplistically) portrayed as an epic argument opposing ‘restrictivists’ and ‘expansionists’. 3 It has focus : positions are clearly articulated; academics take sides – where do you stand on the ‘unwilling or unable’ test; 4 what’s your view on the ‘Bethlehem Principles’; 5 have you signed the ‘Plea against the Abusive Invocation of Self-Defence’? 6 – and do not mince words. 7