As its central theme, WP2 asks how national integration copes with regional diversity. Many ethno-linguistic, ethno-religious, and ‘cultural’ identities in present-day SEA are much older than the nation-state. It is therefore imperative to understand the interactions among these plural identities. The cost-benefits of nation-building are analysed by addressing a range of wider issues such as economic development, national culture, citizenship rights, centralization processes and competing nationalisms. We examine both how dynamics of old and new trans-border and multi-centred identities challenge nation-state hegemonic discourses, and how transnational ethnic groups and networks perpetuate plural identities. The politics of managing national cultural diversity are investigated, looking at relations between governments and local actors, and majority populations with ethnic and religious minorities.