Since the 1990s, transatlantic security cooperation has expanded from traditional military security issues into countering terrorism, international organised crime and drug trafficking. This has had the effect of injecting a new impetus into transatlantic relations, to work together on matters such as the sharing of intelligence information and law enforcement measures. The events of September 11th 2001 have forced these new patterns of cooperation to the forefront of transatlantic relations. While progress has been made, developing this area of cooperation has been more difficult than expected and this book examines the reasons why. The author argues that many of the difficulties are due to the different approaches to these problems on either side of the Atlantic and the absence of a dedicated transatlantic security forum in which these issues could be pursued. Furthermore, the European nations have been preoccupied with the building of the European Union and both reluctant and unable to enter into special patterns of cooperation with the US.