Of all the complex and contradictory aspects of modernity, nationalism is undoubtedly one of the most contested. Within the growing subfield of International Historical Sociology, the theory of uneven and combined development (UCD) has been advanced to explain the "Janus-faced" character of nationalism. Central to this debate is the question of why the historical and spatial expansion of capitalism—an inherently global phenomenon—occurred alongside the creation of economically, politically, and culturally distinct nation-states. In other words, why have the international relations of capitalism operated through a system of nation-states?
This article contributes to this debate by highlighting the significance of Jacobinism for understanding the international relations of modernity. I argue that Jacobinism, though conventionally associated with a brief episode of the French Revolution, activated a historically distinct logic of mobilization and appropriation. This logic generated far-reaching economic, (geo)political, and ideological consequences that shaped the modern world, providing a blueprint for modernization project elsewhere. To illustrate these insights, I examine the case of Kemalist modernization. This historical reconstruction demonstrates that the ambiguities and contradictions of nation-building were rooted, at least in part, in the uneven and combined development of Jacobinism. By doing so, this study contributes to a deeper understanding of the varied sources and outcomes of global authoritarianism.