A comprehensive analysis of the EU as an International Actor and of its foreign policy of 'effective multilateralism', this study describes how the EU has acted as an 'Integrative Power' in the field of peace and security. It highlights how the EU has been promoting closer links not only between states, but also among major international organizations. Relying on detailed case studies, this new research looks at interventions in Macedonia, Bosnia, the Congo, and Chad-and assesses the EU's cooperation with NATO and the United Nations during these emergencies. This book, by Joachim Koops, will provide a valuable resource for graduate students, academics and practitioners interested in the EU as an International Actor, 'effective multilateralism' and the growing phenomenon of inter-organisational relations.