This article examines the relationship between international and national integration in multiethnic states. Focusing on issues of culture, identity and geography, it derives from the extant literature on national integration a set of interrelated hypotheses that describe how a state's foreign ties affect the degree of unity and solidarity among its constituent ethnic and regional groups. Foreign ties influence the cultural characteristics and ethnic consciousness of the people in a state, both symbolically and actually, and thus foreign policy becomes a key element in the construction of national identity and an object of political contestation between groups with different visions of that identity. The article summarizes the results of an empirical investigation of the hypotheses using the case of Ukraine, and suggests other avenues for testing the hypotheses.