'Armed Attack' and Article 51 of the UN Charter : Evolutions in Customary Law and Practice, Tom Ruys

Abstract

The use of force by states in the pursuit of policy objectives remains a salient issue of the international system in our day and age, the legality of which continues to tax the minds of law advisers to states and international organisations, and of academics. The NATO intervention in Kosovo in 1999and the attack against Iraq by a United States-led coalition in 2003, resulted in a deep and rich debate on the legality of the use of force in academic circles and public fora. Belgian legal practitioner and academic Tom Ruys uses an equally seismic event, the 9/11 attacks on the United States, as point of departure for this work, based on his doctoral thesis. He looks at the use of force through the prism of article 51 of the United Nations Charter, which provides for the 'inherent right of individual or collective self-defence if an armed attack occurs.' The work aims to address the vexing questions of what constitutes an armed attack, and the relationship between article 51 and the general prohibition of inter-state use of force in article 2(4), and the relationship between article 51 and the right to self-defence in customary international law.