The post-September 11th security policies of Poland, the UK, France, the US and Germany presented in this new book illustrate how and why the Atlantic community ruptured over Iraq, a result in part, it is argued, of the existence of particular national strategic cultures. Whilst the longer term effects of Iraq for the transatlantic security agenda have yet to fully transpire, what is certain is that the EU's ambitions to become a credible security actor have been seriously questioned, as has the notion of multilateralism as an international norm, as has the function of international law. The book addresses these issues by considering the evolution of the EU's role in the world and the development of American perspectives on the transatlantic security agenda.This volume was previously published as a special issue of the journal European Security.