Exploring the gray zone of infiltration and subversion in which the Nazi and Communist parties sought to influence and undermine each other, this book offers a fresh perspective on the relationship between two defining ideologies of the twentieth century. The struggle between Fascism and Communism is situated within a broader conversation among right- and left-wing publicists, across the Youth Movement and in the "National Bolshevik" scene, thus revealing the existence of a discourse on revolutionary legitimacy fought according to a set of common assumptions about the qualities of the ideal revolutionary. Highlighting the importance of a masculine-militarist politics of youth revolt operative in both Marxist and anti-Marxist guises, Weimar Radicals forces us to re-think the fateful relationship between the two great ideological competitors of the Weimar Republic, while offering a challenging new interpretation of the distinctive radicalism of the interwar era.