This book provides an analysis of non-traditional security (NTS) crises and cooperation between the European Union (EU) and Southeast Asia. Using case studies – transboundary air pollution, marine life endangerment, illegal migration, and terrorism – from both Southeast Asia and Western Europe between 2009 and 2016, this book offers a contemporary understanding of the EU as a collective actor within the Association of Southeast Asian Nations (ASEAN)-EU and Asia-Europe Meeting (ASEM) inter-regional dialogue formats and affiliated programmes. Through new empirical insights into the regional and inter-regional institutional dynamics of the EU and ASEAN in times of crisis and rising nationalism in both regions the author demonstrates, in particular, the relevance of the EU as a security and normative actor and the value of inter-regionalism as a foreign and security tool of the EU in Southeast Asia. Thus, this book underlines the importance of regional organisations in the management of contemporary transboundary NTS challenges within global governance. Enhancing topical debates and offering a timely assessment of crisis-induced regionalism and inter-regionalism in world affairs, this book will be of interest to scholars studying International Relations, International Security, Southeast Asian Studies, European Studies, and Public Policy.