There is a large range of literature on regionalism (the creation of formalised regions with agreed membership) and regionalisation (the process by which regional economies and societies become more integrated) (see inter alia, Coleman and Underhill, 1998; Fawcett and Hurrell, 1995; Gamble and Payne, 1996; Grugel and Hout, 1999; Mansfield and Milner, 1997; Mattli, 1999). There is also a large body of literature on regionalism and regionalisation in East Asia and the Pacific; notably on ASEAN and APEC, and of late on ‘East Asia’ as a voice of region. Indeed, if the volume of literature written on a region was an indicator of the strength of regional institutional development then the Asia-Pacific would be a highly institutionalised region. There is also a growing body of literature comparing regionalism and regionalisation in Europe with East Asia in particular.1 Finally, there are also large bodies of scholarly literature in economic and political science on the theory and practice of institutionalism and international organisation (Katzenstein, Keohane and Krasner, 1998; Simmons and Martin, 2002; Kratochwil and Mansfield, 2005; Higgott, 2006). This last body of literature is evolving and on many issues it is not settled.