Book excerpt: This book studies the role of the EU in peace and security as a regional actor with global aspirations, in the context of challenged and changing multilateralism. Multilateralism, governance and security are three concepts that have attracted a great deal of attention in the past decade and attempts to redefine them have produced lively conceptual debates. More recently, different strands of the literature have found common ground in the investigation of the EU’s role in what has been labelled ‘multilateral security governance’. Despite being frequently used, the term is yet to be fully clarified, and empirically explored. To contribute further our understanding of it, this book presents a conceptual and empirical exploration of ‘multilateral security governance’ and the EU’s role in it. Expert contributors in the field analyze both traditional and non-traditional security areas, to investigate if and how multilateral security governance functions, and how the EU contributes (or fails to contribute) to the functioning of multilateral governance. The EU and Multilateral Security Governance will be of interest to students, scholars and practitioners of EU politics, security studies and governance.