Order, Authority, Nation develops a sociological account of political conversion from left to right through an examination of the historical case of Marcel Déat and the French neo-socialists. Déat and the neo-socialists began their careers in the 1920s as democratic socialists but became fascists and Nazi collaborators by the end of World War II. While existing accounts of this shift emphasize the ideological continuity underlying neo-socialism and fascism, this book centers the fundamentally discontinuous and relational character of political conversion in its analysis. Highlighting the active part played by Déat and the neo-socialists in their own reinvention at different moments of their trajectory, it argues that political conversion is a phenomenon defined not just by a change in belief, but at its core, by how political actors respond to changing political circumstances. This sociological account of a phenomenon often treated polemically offers a unique contribution to the sociology and history of socialism and fascism.