This paper investigates the impact of national threat perceptions on security cooperation within the Association of Southeast Asian Nations (ASEAN). The research includes a review of alliance theory and a study of security regimes which have historically influenced cooperation in Southeast Asia, namely the Southeast Asia Treaty Organization (SEATO), the Five Power Defense Arrangement (FPDA), and security initiatives of ASEAN and the ASEAN Regional Forum (ARF). Using case studies on the key states of Indonesia, Thailand, and Vietnam, a comparative analysis identified the following common threat perceptions: (1) security of the maritime zones; (2) contributions by external forces to internal instability; (3) regional disputes impinging on the sovereignty of one or more of the ASEAN states; and (4) uncertainty over China's interests in Southeast Asia. As an organization of small states not having a significant security guarantor, ASEAN must consider improvements in cooperative security without antagonizing China. An acceptable option for ASEAN is to pursue new increased military cooperation in response to non-state-sponsored threats, such as piracy or natural disaster. This would enhance ASEAN's capability to defend against less benign state-sponsored threats while maintaining conditions favorable to diplomacy and regional stability in Southeast Asia.

ADA 350060 Approved for public release; Distribution is unlimited. The opinions and conclusions expressed herein are those of the student-authors and do not necessarily represent the views of the U.S. Army Command and General Staff College or any other governmental agency. (References to these studies should include the foregoing statement.)