This study examines different levels of security community development between the European Union (EU) and the Association of Southeast Asian Nations (ASEAN). Following security community development model by Emanuel Adler and Michael Barnett, it examines core states, shared ideology, economic transactions and international institutions among EU and ASEAN members that are all conducive to security community development in order to investigate what causes the difference in the development. It also examines mutual trust and collective identity which are the necessary conditions of a security...