David Mitrany (1888–1975) was a Romanian-born academic who spent most of his adult life in Britain and the United States. During World War II, Professor Mitrany thought seriously about the shape of the postwar world and how to prevent future wars. The result of his reflection was a pamphlet entitled A Working Peace System, which he published in London in the summer of 1943, still two years before the end of the war. In this pamphlet, Mitrany argued for a transformation of the way people think about international relations, particularly the prevention of war. His “functional alternative” aimed at world, not European, unity. Nevertheless, it had a profound effect on European activists, such as Jean Monnet (see Chapter 4), and later integration theorists, especially the neofunctionalists (see Chapter 12).