This book provides an in-depth analysis of UK-US intelligence cooperation in the post-9/11 world. Seeking to connect an analysis of intelligence liaison with the wider realm of Anglo-American Relations, the book draws on a wide range of interviews and consultations with key actors in both countries. The book is centred around two critical and empirical case studies, focusing on the interactions on the key issues of counterterrorism and weapons of mass destruction (WMD) counter-proliferation. These case studies provide substantive insights into a range of interactions such as 9/11, the 7/7 London bombings, the A.Q. Khan nuclear network, the prelude to the 2003 Iraq War, extraordinary rendition and special forces deployments. Drawing on over 60 interviews conducted in the UK and US with prominent decision-makers and practitioners, these issues are examined in the contemporary historical context, with the main focus being on the years 2000-05. This book will be of much interest to students of intelligence studies, foreign policy, security studies and International Relations in general. Adam Svendsen has a Phd in International History from the University of Warwick. He has been a Visiting Scholar at the Center for Peace and Security Studies, Georgetown University, and has contributed to the International Security Programme at Chatham House and to the work of IISS, London.