In November 1945, when General George Marshall accepted the mission from President Truman to broker peace between the Chinese Communists and Nationalists, he understood the obstacles he faced and the strategic importance of his effort. The inability to achieve comity between the warring parties in China risked ceding regional influence to the Soviet Union and, more importantly, risked the hard-fought and hard-won peace in the Pacific Theater. Yet by January 1947, Marshall left China without achieving his mission and a few months later, he halted an escalation of American military commitment to the Nationalists. This book examines Marshall's reasoning from an operational perspective and finds that Marshall's decision to end American involvement in China hinged primarily on operational factors. To make the case for this work, this book surveys the lessons Marshall learned in China as a lieutenant colonel from 1924 to 1927 in terms of mission variables and looks to how he applied these lessons during his assigned mission from 1946 to 1947.