The existing postcolonial literature privileges the British and French imperial/colonial history that mirrors the ongoing debate on the relationship among cosmopolitanism, universalism, and imperialism. These debates take for granted the Kantian and Hegelian hierarchy of European civilizations, hence marginalizing the southern shores of Europe and the broader Mediterranean space. Drawing on Mignolo's notion of “border thinking” and on Isin's account of the city as a “difference machine,” I address the issue of how imperialism, colonialism, and cosmopolitanism come together and relate to each other in the context of the Mediterranean (allegedly) cosmopolitan cities. In particular, cosmopolitanism is read as the outcome of the reciprocal adjustment of interior and exterior borders in the making of modernity/coloniality in the Mediterranean. Focusing on the Ottoman millet system, my main claim in this article is that cosmopolitanism worked as a peculiar dispositif within the urban difference machine, enabling the city to sustain the tension between different accounts of citizenship.