This study analyzes the French anarchists’ responses to the Russian and Spanish revolutions, and to the creation of an international communist movement, between the World Wars. It details the dilemmas facing anarchism at a crucial moment in the movement’s history, a time characterized by serious questioning of traditional anarchist theory and practice. On the basis of original research using the anarchist movement’s press and other publications, as well as archival sources, Berry concludes that the French anarchist movement was not as isolated as has been previously suggested and that it was in fact probably stronger in the 1930s than it had been before or since.