The Allied peacemakers at Versailles—Georges Clemenceau, David Lloyd George, and Woodrow Wilson—have never recovered from history’s judgment that in ending one world war, they sowed the seeds of the next. Under the Treaty of Versailles, the French did not get the security guarantees they wanted, the Germans were humiliated, the Americans spurned the League of Nations, and outside the West, nationalist movements for self-determination were thwarted. Sharp, however, offers a more sympathetic judgment of Versailles. World War I had set in motion vast forces that were almost too much for diplomats to manage: the collapse of four empires, the implosion of the European great-power order, the Anglo-American power transition, the rise of revolutionary Russia, and the spread of new ideas about self-determination. Sharp argues that the treatment of Germany—a “tough peace” that lacked an enforcement mechanism and undermined Germany’s fragile democracy—was doomed to fail. But the League of Nations, he says, opened up a new era of social and economic cooperation and laid the foundation for the un. A century after Versailles, self-determination has triumphed, but many of the dilemmas faced by the peacemakers of 1919 remain.