Anticipatory action in self-defence: essence and limits under international law

The controversies in international legal scholarship on the permissible modalities of use of self-defence by states have not ceased since the adoption of the Charter of the United Nations, which embodied in Article 51 the ‘inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations’. Divergent interpretations of Article 51 itself, and of the relation of the latter with the pre-existing customary (‘inherent’) right of self-defence arguably left ‘unimpaired’ by the Charter, result in uncertainties regarding the precise qualification, and thus the international legality, of most incidents since 1945 where self-defence has been actually invoked by states, often in relation to threats or imminent attacks. These incidents range from early claims of preventive self-defence of Pakistan in Kashmir in 1947–8, and of Israel in 1948, to the recent case of intervention of the Arab coalition led by Saudi Arabia in Yemen in 2015. This uncertainty in turn can be said to undermine the international rule of law, and has thus understandably long attracted the attention of legal scholars. The book under review is structured in three parts: Part I is devoted to preCharter customary international law on self-defence, and Part II to postCharter customary international law. Part III then builds on the findings of parts I and II to set out conclusions on the legality of anticipatory action in self-defence, as well as its limits. The author of Anticipatory Action in Self-Defence: Essence and Limits under International Law attempts at clarifying the debates surrounding the temporal dimension of self-defence by focussing on two research questions: first, is anticipatory action in self-defence part of customary international law? And, second, if so, what are its limits? At the outset, the author correctly identifies in Chapter 1 three main groups of authors, based on their views on the temporal dimension of self-defence. The first group ‘adopts the view that Article 51 [of the Charter], as an