National Security and the Right of Self-Defence: an Exposition of International Law and State Practice

Abstract

The right of self-defence remains one of the most contested and vital principles in contemporary international law. This article offers a comprehensive overview of the legal framework governing the use of force in self-defence, examining both its theoretical foundations and practical application in state practice. The theoretical basis for the study is rooted in Realism Theory. The research methodology employed is qualitative. The study utilises both primary and secondary sources. By analysing the United Nations Charter, customary international law, and jurisprudence from the International Court of Justice, this article traces the evolution of the self defence doctrine from its traditional conception to its modern challenges. It critically assesses the tensions between Article 51 of the UN Charter and customary international law, the principles of necessity and proportionality, the doctrine of anticipatory self-defence, and the contentious idea of pre-emptive action. Additionally, it examines state practice across various contexts, including armed attacks by non-state actors, cyber operations, and humanitarian issues. The article argues that although the legal framework imposes essential limits on the use of force, ambiguities in interpretation and inconsistent state practice pose significant challenges to international peace and security. Among other recommendations, it suggests that the international community should aim for greater clarity and consistency in defining and applying self-defence standards. The article concludes by addressing current debates, including the attribution problem in attacks by non-state actors, the sufficiency of existing law for cyber warfare, and the importance of 
multilateral cooperation in clarifying and strengthening the international legal regime governing self-defence.