This new edition is fully revised and updated following the Gulf War, the fighting in the former Yugoslavia and the political changes that have occurred with the ending of the Cold War. This book re-examines the topics of war, aggression and self-defence, including discussion on the legal nature of war, peace treaties, neutrality, the contemporary prohibition on the use of force, crimes against peace, war crimes and State sponsored terrorism. Related issues, such as collective security and the use of force short of war, are also addressed. Reflecting the recent increase in the use of force and counterforce at a regional level, special attention is given to the respective roles of the Security Council, the General Assembly, and the International Court of Justice in the developing 'New World Order'.