Introduction. From Sputnik to Chernobyl: science and the European left during the Cold War

This special issue examines the complex and evolving relationship between science and the political Left in twentieth-century Europe. It argues that science functioned both as an instrument of political action and as an ideal of rational order, shaping left-wing visions of modernity, progress and democracy. Drawing on the concept of partisan visions of science, it analyses how political actors mobilised scientific authority within ideological and electoral frameworks. The contributions use case studies to situate these dynamics within a broader historical shift from the mid-century’s technocratic optimism to the post-1970s ‘risk society,’ tracing how the Left’s faith in progress gave way to scepticism amid ecological crises, anti-nuclear activism and postmodern critiques of rationality. By linking political history with Science and Technology Studies (STS), the article explores tensions between expertise and democracy, the rise of counter-expertise and the challenges of scientific authority. Ultimately, it argues that while the Left once identified science with emancipation, science has been recast as a source of planetary risk, especially in the Anthropocene. The enduring ambivalence of scientific modernity continues to shape progressive politics, raising the question of whether a new synthesis between science and the Left remains possible.