The purpose of this study is to critically evaluate three scholarly perspectives -- balance of power, institutional, and security complex -- to examine the evolving dynamics of security interdependence and inter-state relations among Southeast Asian states and external powers since 1945. This study is thus a comparative evaluation of the strengths and weaknesses of the three methods in their empirical analysis of the regional security dynamics of Southeast Asia.¶ There is much merit in the balance of power approach. It tracked the consequences of the bipolar Cold War rivalry on Southeast Asia. Its logical construction led it to be concerned with alliances, coalitions and alignments. But it has not satisfactorily explained the relatively benign conditions after the Cold War. The institutional approach similarly emphasizes material explanatory factors (although, in its case, not exclusively so). It identifies the emergence of institutions when groups of countries find it in their mutual interest to cooperate through rules and norms. But the approach may prove to be incomplete in assessing ASEAN's post-Cold War behaviour. As an analytical device, the security complex is deployed to provide a corrective to the over-emphasis (of the other two approaches) on the systemic dynamics. By identifying regional and local dynamics interacting with systemic dynamics via patterns of amity and enmity, it offers explanatory accounts of the behaviour of regional states in situations where the other two approaches fail to do satisfactorily. Moreover, it provides a framework for the deployment of constructivism, which identifies the ideational process whereby interdependent regional states respond to changes in both the power and amity-enmity attributes.¶ This study concludes that security relations among Southeast Asian states and in their relations with external powers after the Cold War, are better examined using the three approaches in a complementary manner. In this way, the influence of local amity-enmity patterns is seen to impact on balance of power and institutional situations.