Maynard Keynes' first great impact on international relations came with the publication in 1919 of The Economic Consequences of the Peace, his indictment of what he saw as the iniquities of the Versailles Treaty and the repellent behavior of the major leaders of the victorious democracies. He was moved partly by the fact that his own ideas had been overruled, as they had been several years before concerning the issue of what kind of war Britain should fight. Failure undermined his rationale for serving the government throughout the war in positions of great responsibility in spite of the criticism of his anti-war friends, his distress at the slaughter and his distaste for a world in which Britain had become financially dependent on the Americans. There were additional factors, including pro-German and anti-French elements in his upbringing and a philosophy derived from the Cambridge milieu that put the highest value on personal relations. We can understand and weigh these elements better than ever before, thanks to this excellent interpretive biography, which draws on a wide range of published and unpublished material.