This book is an analysis of European intelligence cooperation from the 1990s to present day. The study, which is the first to deal with supranational and intergovernmental policy bargaining post-September 11, 2001, is based on primary interviews with civilian and military policy-makers in London, Paris, The Hague and Brussels, and includes three particular case studies of the International War Crimes Tribunal for the Former Yugoslavia, European intelligence co-operation during the Kosovo War (1998-9), and European intelligence co-operation after 9/11. Intelligence collection, collation and analysis is fundamental to cultivating a global defence mechanism. Since 9/11, there has been a growing realisation in Europe and among EU member states that the 'new' security threats -- migration, terrorism and rogue states -- can be tackled best by greater European/EU cooperation. This book addresses the very substantial foreign policy and international relations issues that arise from creating an integrated defence policy.