Countless studies have assessed the dramatic reforms of Mikhail Gorbachev, but their analysis of the impact on European communism has focused overwhelmingly on the Soviet Union and Eastern bloc nations. This ambitious collection takes a much broader view, reconstructing and evaluating the historical trajectories of and on both sides of the Iron Curtain. Moving beyond domestic politics and foreign relations narrowly defined, the research gathered here constitutes a transnational survey of these reforms’ collective impact, showing how they were variably received and implemented, and how they shaped the prospects for “proletarian internationalism” in diverse political contexts.