Many students of International Relations tend to take “nation-states” as given. Notwithstanding the widely recognized difficulties of defining nationalism, Jens Bartelson argues that, in International Relations, “nationalism … is portrayed as a baseline fact of international politics, as an immutable outcome of an irreversible process”. Yet despite increasing attention given to the impact of ill defined processes of globalization and to questions of identity by post-colonial theorists and critical International Relations’ scholar, nationalism appears to be both central to and marginalized in mainstream International Relations. This article explores the ambiguous relationship between nationalism, which we understand as the desire for the convergence of nation and state, and state-centric discourses of realism and liberalism in the discipline of International Relations.