This book examines the European Union's contribution to providing security in Europe amidst an increasingly complex and challenging environment. In this new and comprehensive guide to the EU's role in security since the end of the Cold War, the authors offer an explanation of EU internal and external security regimes, and argue that the Union has become an important exporter of security within its region. However, the Union's rhetorical ambitions and commitments continue to outstrip its capabilities and it lacks both a common conceptualisation of security and a meaningful, shared strategic culture. Drawing extensively on primary sources the book examines the Union's relations with the US and Russia in a time of shifting geostrategic calculations and priorities. With the EU capacity for enlargement slowing, this text presents a detailed assessment of EU security policies towards Central Europe, the Mediterranean, the Western Balkans, Eastern Europe and South Caucasus. European Union Security will be of interest to students and scholars of the EU, security studies, and international relations.