Scholars of Kant are often puzzled by his strong defense of sovereignty and patriotism along his cosmopolitanism. Interpretations that try to make sense of these commitments privilege the domestic sphere, arguing that virtuous citizens in developed republics is bound to result in cosmopolitan feeling and action. This account, however, demotes the cosmopolitan realm to a dependent position in Kant’s system of Right, thus failing to account for the more reciprocal notion of complementarity between the domestic, the international, and the cosmopolitan in Kant. I offer textual evidence to support this reciprocal notion of complementarity and the connected notion of hospitality, which Kant puts forward to address the inevitable inter-dependence between the domestic, international and cosmopolitan realm. Ultimately, however, Kant’s theorization of these notions, and his illustrations of the possible interactions are limited by his predominant concern with European stability. In order to expand and politicize these principles I rely on Du Bois’s conceptualization of transnationalism, which highlights the common origin of injustice across spheres, the potential of emancipatory political action that straddles several realms of politics, and the subjective transformation that these practices entail for the political actors involved. I illustrate these dynamics with three events spearheaded by Du Bois in the inter-war and post-Second World War periods to show that cosmopolitan and civic loyalty stand in a complementary relation in a way that does not privilege one realm above the others.