Since the late eighteenth century, nationalist movements have been one of the world’s most powerful agents of social change. As a social movement, nationalism serves as a primary instrument both for popular aspiration and for ruling ideology. It is embedded in political contexts and can only be explained in relation to the resulting dynamics of contention. There is considerable debate over types of nationalist movements and their role in history, in large part because nationalism is not often explicitly conceptualized as a social movement. These debates, especially those that played out through the 1980s and into the mid-1990s, offer important insights into nationalist mobilization and its conditions of emergence and development. In order to understand the dynamics of nationalism as a social movement, one may draw insights from the “political process” school of social movement scholarship, where the exercise of state power is seen as framing movement identification and as structuring mobilization. Three interrelated dimensions deserve consideration in this regard: material interests and resources, institutional opportunities, and ideological framing of nationalist mobilization. Each is linked to the other by a process of capitalist development that creates systemic inequalities and fragments global society into national units. What emerges is a political sociology of nationalist movements, where movements are embedded in the social forces that they inhabit. The interaction of social forces and nationalist mobilization can be conceived of as a hierarchy, where one leads to the other.