Nationality has been a key identity in international relations for much of the modern period, and the marriage of “nation” and “state” produced a powerful polity – the national state – that dominated global politics. This article investigates the forces that “pushed” and “pulled” nations and states together and explores the factors associated with violent identity politics. It argues that while recent decades have witnessed increasing instances of divorce between “nation” and “state” and a simultaneous proliferation of identity conflicts, the likelihood that identity conflicts will be expressed violently depends both on the character of the state (the timing of state institutionalisation relative to the construction of national consciousness, the democratic or non-democratic nature of the state, and the national or non-national basis for the legitimation of state authority) and on the principal “marker” used to construct national identity (blood, language, culture, religion, or citizenship).