The constructivist study of norms faces two central challenges-reintegrating agency into its largely structural accounts and unpacking its arguments at the national level. This article addresses these issues, and does so in four parts. First, I briefly review the burgeoning constructivist literature, exploring the ontological and theoretical reasons for its neglect of agency. Second, by adding social content to the concept of diffusion, the transmission mechanism linking international norms to domestic change, I explain the motivation of domestic actors to accept new normative prescriptions, thus making a start at restoring agency to constructivist accounts. Third, I argue these key actors will vary cross-nationally as a function of state-society relations ("domestic structure"). Fourth, the argument is applied to the politics of national identity in post-Cold War Europe. In particular, I examine the degree to which international norms are affecting debates over citizenship and national minorities in contemporary Germany, with empirical data drawn from the European human rights regime centered on the Council of Europe.