The fall of the Berlin Wall and the end of the Cold War sparked a debate in the study of world politics. Scholars scampered to offer explanations for these unforeseen events. Some argued that the end of the Cold War demonstrated the importance of agency and ideas— specifically Mikhail Gorbachev's New Thinking. Others responded that traditional theories of power politics could explain the changes in Soviet foreign policy that transformed Eastern Europe in the late 1980s. We contend that one cannot explain the fall of the Berlin Wall and the end of the Cold War without placing Soviet Union foreign policy in its unique revolutionary context. Soviet foreign policy had been based on the principle of externalization, going back to the period immediately after the revolution. Threats from abroad justified extreme centralization, repression, and monopolistic one-party rule. Gorbachev strove to revitalize the idea of the Soviet Union as a revolutionary state and acted as a "counterrevolutionary" in attempting to change the fundamental assumptions of Soviet foreign policy, promoting a friendly international environment that would help to decentralize the Soviet system, end repression, and advance a more pluralist order. This counterrevolution failed and led to the collapse of the Berlin Wall, the Soviet empire, and the Soviet state itself.