This article provides a historically informed analysis of the contemporary incorporation of Islam and Muslims into an idea of common – national – membership in the United States and Britain. It shows that there is a current movement towards synthesis between religious and national identities by Muslims themselves, and explores the ways in which this synthesis is occurring within rich and dynamic public spheres in societies that have historically included and incorporated other religious groups. The authors argue that both countries are wrestling with the extent to which they accommodate Muslims in ways that allow them to reconcile their faith and citizenship commitments, and that the British ‘establishment’ is no less successful at achieving this than secular republicanism in the US.