'Armed Attack' and Article 51 of the UN Charter
Evolutions in Customary Law and Practice

An examination of the scope of States' right of self-defence under Article 51 of the UN Charter in the post-9/11 security environment.

Tom Ruys (Author)

9780521766647, Cambridge University Press

Hardback, published 25 November 2010

616 pages
22.9 x 15.2 x 3.8 cm, 1.07 kg

'Tom Ruys has written one of the most important books on the Charter law on the use of force. His study is meticulously researched, methodologically sensitive, extremely thoughtful, and elegantly written and on top of all this, it shows balanced judgment. It must therefore be included in the rather short list of significant monographs on the subject-matter … by having written this splendid book, Ruys has rendered the determinacy of this crucially important body of law a most valuable service.' Claus Kreß, British Yearbook of International Law

This book examines to what extent the right of self-defence, as laid down in Article 51 of the Charter of the United Nations, permits States to launch military operations against other States. In particular, it focuses on the occurrence of an 'armed attack' - the crucial trigger for the activation of this right. In light of the developments since 9/11, the author analyses relevant physical and verbal customary practice, ranging from the 1974 Definition of Aggression to recent incidents such as the 2001 US intervention in Afghanistan and the 2006 Israeli intervention in Lebanon. The notion of 'armed attack' is examined from a threefold perspective. What acts can be regarded as an 'armed attack'? When can an 'armed attack' be considered to take place? And from whom must an 'armed attack' emanate? By way of conclusion, the different findings are brought together in a draft 'Definition of Armed Attack'.

Introduction
1. The methodological debate and the quest for custom
2. Conditions of self-defence
3. The Armed Attack Requirement Ratione Materiae
4. The Armed Attack Requirement Ratione Temporis
5. The Armed Attack Requirement Ratione Personae
6. What future for the armed attack criterion?

Subject Areas: International humanitarian law [LBBS], Public international law [LBB], International relations [JPS]