This paper recounts the East Asian experience with the construction of Defence-related architecture to date. It recalls some earlier history of the ARF, viz: the adoption of a Concept Paper, containing a large menu of possible confidence-building measures and other proposals for security cooperation, including numerous Defence-related measures, in 1995. It also describes in some detail the recent history of the ASEAN-led forums for Defence dialogue and cooperation which contributes to the identification and elucidation of at least some of the principal elements of a 'Southeast Asian Defence Model' which frames thee agenda for prospective cooperation. The paper discusses recent developments in the North Atlantic Treaty Organisation (NATO) and European Union (EU), and argues that the pruposes, sturctures, operational modalities and achievements of these organisations are not central to any consideration of East Asian security architecture. On the other hand, their recent experiences in important areas such as peace-keeping, missile defence and cyber security warrant serious reflection. The paper offers some proposals concerning half a dozen areas for substantive future consultation and cooperation by the constituent mechanisms of the Defence component of the East Asian security architecture. They involve a composition of the unremitting security challenges requiring regional resolution and the principle elements of a Southeast Asian Defence model, as manifested in the record of achievements to date. Construction of the Defence part of the architecture sufficiently robust to effectively address the regional security challenges will require both reform of the Defence pieces into a more integrated, coherent and efficient structure and also disposal of some of the more dysfunctional aspects of the Southeast Asian Defence Model.