PRE-EMPTIVE AND PREVENTIVE SELF-DEFENCE IN INTERNATIONAL LAW: LEGAL CONSTRAINTS AND APPLICATIONS IN THE ISRAEL-IRAN CONFLICT

Abstract

The escalation of hostilities between Israel and Iran has revived longstanding debates concerning the scope and legality of pre-emptive self-defence under international law. This article critically examines whether anticipatory uses of force can be accommodated within Article 51 of the United Nations Charter, which recognises the inherent right of self-defence only “if an armed attack occurs.” It interrogates the doctrinal requirement of an armed attack, the continued relevance of customary international law as reflected in the Caroline Incident, and the extent to which evolving security threats such as missile proliferation, cyber operations, and proxy warfare challenge traditional interpretations of imminence. Drawing on the jurisprudence of the International Court of Justice, particularly in Nicaragua, Oil Platforms, and Armed Activities, the article demonstrates that international law maintains a deliberately restrictive threshold for the lawful exercise of self-defence. It argues that attempts to broaden Article 51 to justify pre-emptive or preventive action risk eroding the prohibition of the use of force enshrined in Article 2(4) of the Charter. While contemporary security realities may exert pressure for doctrinal flexibility, the article contends that preserving the integrity of the collective security system requires adherence to a narrow interpretation of self-defence. Consequently, claims of pre-emptive self-defence in the Israel-Iran context remain legally tenuous and normatively problematic.