This fine and lucid scholarship has the additional benefit of the eye of an experienced practitioner as Zelikow addresses the question of whether U.S. President Woodrow Wilson could have mediated a peace deal in 1916 or 1917 to end World War I before the United States joined the fray. The reader is aware—although the policymakers of the time could not have been—of the difference that an early deal might have made, perhaps sparing the world the later traumas associated with the rise of Bolshevism in Russia and Nazism in Germany. Wilson was certainly keen to mediate a wider peace, and all the belligerents were aware of the benefits of at least being seen to negotiate. After a promising start, however, Wilson never quite managed to give the effort the push it needed. The demands of winning reelection inhibited him, as did his dependence on a lackluster State Department. It didn’t help that in the United Kingdom, David Lloyd George, who was then secretary of state for war, correctly surmised that an aggressive, uncompromising posture would help propel him to the position of prime minister. For its part, Germany adopted a policy of unrestricted submarine warfare. This led Wilson to break diplomatic relations with the Germans, too hastily in Zelikow’s view. The opportunity for a brokered peace was lost.