Abstract:Regionally-based processes of political and economic integration, security cooperation, and even social identification have become increasingly important and prominent parts of the international system. Nowhere have such processes gone further than in Western Europe. Somewhat surprisingly, similar patterns of regional integration have been steadily developing in East Asia -a region many observers consider unlikely to replicate the European experience. What are the factors that encourage regional political cooperation and economic integration? Are there common forces encouraging such outcomes in very different geographical areas and at very different moments in history? This paper uses an historically grounded comparative approach to examine the historical pre-conditions that underpinned the formation of the European Union, and then contrasts them with the situation in East Asia today. While the overall geopolitical and specific national contexts are very different, the East Asian experience may ultimately generate relationships and structures that are more like the European Union's than some of the sceptics imagine.One of the most widely noted and counter-intuitive features of the contemporary 'global' era is that it has a distinctly regional flavour. While it is true that some of the globalisation literature has been over-heated and over-generalised, the persistence -if not the intensification -of regional processes is still striking and somewhat surprising. Whether it is measured by trade and investment flows, political cooperation, or even the development of regionally based security communities, it is clear that regionally-based interactions are central components of the international order at the start of the twenty-first century.While there is now a substantial and growing literature on regionalism (see, Mansfield and Milner 1999), this generally focuses exclusively on the 'new' variety, which gathered pace in the aftermath of the Cold War's end, and which is primarily