Introduction In 1967 Thailand, Singapore, Indonesia, Malaysia, and the Philippines signed the ASEAN Declaration, but the convening of the first summit meeting of heads of state was held only in 1976 (Bali), when they adopted the Concord Declaration and the Treaty of Amity and Cooperation in Southeast Asia. In time, Brunei, Vietnam, Laos, and Myanmar joined, with Cambodia likely to follow soon. The evolution of ASEAN has led to different interpretations of its essence, viability, and future. On the one hand, some scholars have pondered about its strength and durability, and about the extent to which ASEAN represents anything beyond business-as-usual inter-state politics, of the kind that Neo-Realist approaches have described best.(1) Thus viewed, ASEAN's behaviour - including some co-operation -can be most easily explained in terms of inter-state competition, power balancing, and arms races. On the other hand, ASEAN can be understood as a cooperative regional framework traceable to a converging pattern of domestic politics.(2) This view accommodates robust regional co-operation that eschews military competition and follows the logic of the domestic political forces that created and nurtured it. The article subjects some key theoretical propositions embedded in the second approach to an empirical overview of ASEAN in recent decades. The section that follows outlines a set of expectations about ASEAN's behaviour, derived from a domestic coalitional perspective. Accordingly, ASEAN can be understood as a regional cluster of internationalist coalitions that co-operate with one another to advance their grand strategy, encompassing domestic, regional, and international objectives. The subsequent section examines the historical record from a coalitional viewpoint. Anchoring the analysis of ASEAN on the nature of domestic coalitions does not imply that more classical security dimensions and the role of external powers are irrelevant. Far from it, the global political, strategic, and economic contexts are an integral part of a coalition's grand strategy of political survival at home, even if the confines of this article force only a cursory treatment of this broader context. The conclusion explores the advantages and shortcomings of this perspective, and suggests that the post-1997 regional crisis offers yet another important test of the coalitional interpretation advanced here. Domestic Coalitions and Internationalist Grand Strategies The emergence and international behaviour of ASEAN can be interpreted by analysing the domestic political coalitions responsible for ASEAN's genesis and growth. Which domestic coalitions within the ASEAN states saw it to their advantage to establish a co-operative framework rather than a competitive regional structure? As will be argued, the ASEAN states came to be progressively under the control of internationalist coalitions and it is the grand strategy of these coalitions that explains why a co-operative regional order evolved over time. A brief overview of coalitional variants and of the relationships among coalitions, grand strategy, and regional outcomes is in order.(3) The central features of internationalization are openness to international markets, capital, investments, and technology. Internationalization affects individuals and groups in different sectors via changes in employment status, labour incomes, and returns on assets, via changes in prices of goods and services consumed, and via the provision of public services. The distributional consequences of internationalization create two ideal-typical political coalitions in each country, one supporting it (internationalist coalitions), the other opposing it (backlash coalitions). Internationalization does not merely pose threats to material interests but also to cultures, identities, and values, and to the interests of political entrepreneurs endangered by both types of threats. Thus, coalitions are not merely about alternative positions vis-a-vis economic liberalization but about alternative integrated interpretations of the political-economic and strategic context as it affects domestic coalitional balances. …