Through a pioneering analysis of two critical junctures in EU counter-terrorism, this topical book examines the drivers, conditions and impediments for policy integration and information-exchange institutionalisation in EU counter-terrorism. Taking a deep dive into the key questions surrounding EU counter-terrorism, Christine Andreeva utilises distinct terrorism case studies over two decades to investigate the evolution of information-sharing in EU counter-terrorism. Using an innovative theoretical framework combining historical and constructivist institutionalism, the book examines key events in EU counter-terrorism development: the 2015-2016 Paris and Brussels attacks and the 2004-2005 Madrid and London attacks. Identifying a post-2015 paradigm policy shift, the book traces the increased efficiency of cross-border and inter-agency co-ordination in the EU's counter-terrorism policy. Andreeva demonstrates how institutionalisation, information-sharing and improved legislative frameworks have led to further policy integration and added significant value to international EU counter-terrorism efforts. Illustrating the importance of practitioners' perception of EU added value in counter-terrorism, this book will be essential to scholars and students of public policy, particularly those studying EU and international politics and EU counter-terrorism. Its empirical findings will also be useful to policymakers and practitioners in security and counter-terrorism fields.