Many social movement scholars have devoted their work to the relationship between repression and mobilization. However, research has not produced consensus, but a ‘dizzying array of empirical findings’ (Earl 2006). This paper aims to open the debate using a transnational perspective that transcends the predominant attention in the literature to domestic, democratic settings. It analyzes the role of international factors in shaping contentious politics in undemocratic settings. The research question can be summarized as to what extent the end of World War II in Europe affected the relationship between state repression and anarchist mobilization in Francoist Spain. This paper uses the time of crisis following the end of the war as an independent variable in explaining changes in the repression-mobilization nexus. The allied victory was a transformative event in so far as it represented a turning point in the international context of political opportunities, which produced dramatic changes in the levels of mobilization and repression even in countries not directly involved in the war. The extent of this impact as well as the internal dynamics of subsequent collective action processes are analyzed here. The sources used include a range of archival material as well as memoirs from both challengers and power-holders. In the end, the paper advances some hypothesis on the relationship between political opportunities and the international context.