Part III The Prohibition of the Use of Force, Self-Defence, and Other Concepts, Ch.27 The Resilience of the Restrictive Rules on Self-Defence

Subject(s):

Self-defence — Armed attack — UN Charter — Vienna Convention on the Law of Treaties — Treaties, interpretation — Customary international law — Opinio juris — Peremptory norms / ius cogens

This chapter examines the resilience of the treaty, and perhaps also customary, law on self-defence since 2001. It first considers ‘resilience’ in the context of the jus ad bellum and how law can be resilient vis-à-vis changing circumstance, opinions, interpretation, and state practice. It then looks at the indicators for and against resilience by analysing post-2001 developments, paying particular attention to three areas: jurisprudence, scholarly literature in international law, and state and institutional practice. The chapter also explains what ‘resilience’ can and cannot be, and how the law and its perceptions change—or remain the same. Two avenues on the question of what is resilient are evaluated: either the norm or its interpretation (perception) change. Finally, the chapter considers a number of cases in which the International Court of Justice has made pronouncements on and partial clarifications of important aspects of the law on self-defence since 2001.