At the end of World War II, General George Marshall took on what he thought was a final mission―this time not to win a war, but to stop one. In China, conflict between Communists and Nationalists threatened to suck in the United States and escalate into revolution. Marshall’s charge was to cross the Pacific, broker a peace, and prevent a Communist takeover, all while staving off World War III. At first, the results seemed miraculous. But as they started to come apart, Marshall was faced with a wrenching choice―one that would alter the course of the Cold War, define the US-China relationship, and spark one of the darkest-ever turns in American politics. To help explain this aspect of the U.S. China relationship we interview Daniel Kurtz-Phelan is Editor of Foreign Affairs. He previously spent three years as Executive Editor of the magazine and served in the U.S. State Department, including as a member of the Secretary of State’s Policy Planning Staff. His book on George Marshall’s post­–World War II mission to China, The China Mission, was published in 2018 and named a best book of the year by The Economist and an editor’s pick by The New York Times Book Review. His writing has also appeared in publications including The New York Times, The Washington Post, and The Atlantic. We also explore the Korean War, the Vietnam War, and the Nixon opening, all of which had a large impact on shaping modern U.S.-China relations.