The course examines key aspects of the contemporary international relations of Southeast Asia, with the primary focus being on the intramural relations of the member states of the Association of Southeast Asian Nations (ASEAN). In order to contextualise these intramural relations, the course briefly explores the different domestic political settings in which Southeast Asian decision-makers operate, the ethnic struggles for autonomy taking place in some ASEAN countries, historical interstate tensions and conflict as well as transnational security challenges faced more recently by members of ASEAN. Also taking account of geographical factors, economic interests, political change, and leadership ambitions, the course then engages in a comparative analysis of the foreign and security policies of some of the original member states of ASEAN toward near neighbours and the wider region. The analysis then shifts to how the respective domestic backdrop and foreign policy outlook of Southeast Asian states have shaped the nature, effectiveness and limits of ASEAN as a vehicle for intramural political-security cooperation. Specifically, the course examines ASEAN’s evolving practice of non-interference, its status as a security community, and its responses to challenges concerning human rights, humanitarian assistance and the responsibility to protect. The course will conclude by examining how to make sense of growing investment across parts of Southeast Asia in defence modernisation, not least new naval capabilities.