This book surveys a new trend in immigration studies, which one could characterize as a turn away from multicultural and postnational perspectives, toward a renewed emphasis on assimilation and citizenship. Looking both at state policies and migrant practices, the contributions to this volume argue that (1) citizenship has remained the dominant membership principle in liberal nation-states, (2) multiculturalism policies are everywhere in retreat, and (3) contemporary migrants are simultaneously assimilating and transnationalizing.