This chapter argues that even working-class labour migrants may become cosmopolitans, willing to 'engage with the Other'; and that transnationals inevitably must engage in social processes of 'opening up to the world', even if that world is still relatively circumscribed culturally. Against the globalizing Northern (or Western) thrust of economic goods, technological experts and mediatized images, it considers a counter-trend: the emergence of complex transnational ethnic or religious cultural worlds, created by vast flows of labour migrants. Migration is a class-related phenomenon, and notions of transnationalism or cosmopolitanism as cultural phenomena are of necessity class related. The powerful attraction of diaspora for early postcolonial theorists was that, as transnational social formations, diasporas challenged the hegemony and boundedness of the nation-state and, indeed, of any pure imaginaries of nationhood. The most recent challenge to the cosmopolitan vision of diaspora has come from the post-9/11 emergence of Islamic 'terror' cells apparently embedded within settled post-war diasporas in the West.