Contemporary international politics embody a tension between formal equality and de facto inequality. States recognize each other as sovereign equals, yet the strong still push around the weak. Among the structures that reflect this tension are informal empires. The dominant assumptions in mainstream international relations theory, materialism and rationalism, privilege the formal equality of states in informal empires a priori: materialism by assuming that authority relations cannot exist between sovereign states; rationalism by assuming that states are sovereign over their own interests. A constructivist approach allows one to explore the hypothesis that transnational authority structures construct state identities and interests. An empirical analysis of the Soviet-East German relationship supports this hypothesis, which raises questions about the emerging study of international governance.