Conceptualizing the sovereign nation-state remains a core concern in the discipline of international relations (IR). Yet, as the volumes by Sarah Owen Vandersluis and Beate Jahn demonstrate, the theoretical location of this conceptual debate is shifting. Questions of identity, like those regarding sovereign nation-states, were answered in the 1990s with reference to terms like social construction. In the new millennium, “the social” is increasingly joined by “the cultural” as an intellectual marker of how serious IR scholars must pose questions of identity. Why this shift? And what difference does it make to our understandings of sovereign nation-states, not to mention IR theory more generally?