This exceptional volume examines international security issues by way of case studies of the conflicts in Afghanistan and Iraq. Each of these raises significant issues concerning the use of force between states and the role of the United Nations in maintaining international peace and security. Alex Conte examines international terrorism and the intervention in Afghanistan, including the controversial policy of pre-emptive strikes in the war on terror, and discusses the role adopted by the United Nations in the political and economic reconstruction of states subjected to conflict. Analyzing events in Iraq since 1990, he assesses the legality of the current war and leads to an examination of the role of the UN in maintaining peace and security and possible options for reform and accountability. The study will be a valuable guide for all those keen to understand the use of international law and the United Nations in the first two major conflicts of the 21st century and their implications for the future role of the United Nations.