These 9 papers are from the 2010 international workshop of the Rajaratnam School of International Studies, Nanyang Technological University. After an introductory overview the specialist papers explore: ASEAN Defence Establishment roles in the evolving Regional architecture; ASEAN's quest for practical security cooperation through the ASEAN Defence Ministers' Meeting (ADMM) and ADMM-plus Processes; The Five Power Defence arrangements and Regional Security Architecture; the Shangri-La Dialogues; the relevance of Network of ASEAN Defence and Security Institutions (NADI) to the ADMM; Trends, prospects and challenges in Defence Diplomacy; China's Defence Diplomacy in Southeast Asia; US Defence Diplomacy in Southeast Asia.