Studying religion in diaspora has become a prominent part of the study of contemporary religion and public debate since the early 2000s. The research field emerged somewhat differently in North America and Europe. The Americans were initially more interested in immigrant congregations and their activities in all their variety (e.g. Warner and Wittner, 1998), whereas Europeans focused much more selectively on Muslim immigrants, although still with a focus on their religious organizations (e.g. Nielsen, 1992). The field was soon influenced by the growth of globalisation and transnationalism studies (e.g. Beyer, 1994; Levitt, 2001). More recently, political science has provided insights about the role of the nation state and the wider social and political implications of this new religious diversity in the global age (e.g. Laurence, 2012). The question is, does something beyond the sheer emergence of this new level of religious diversity in the West, and its often problematic association with global conflicts since 9/11 especially, make it politically more important than it seemed in preceding decades?