Ralph Bunche , in full Ralph Johnson Bunche (born Aug. 7, 1904, Detroit, Mich., U.S.—died Dec. 9, 1971, New York, N.Y.), U.S. diplomat, a key member of the United Nations for more than two decades, and winner of the 1950 Nobel Prize for Peace for his successful negotiation of an Arab-Israeli truce in Palestine the previous year.

Bunche worked his way through the University of California at Los Angeles and graduated in 1927. He also earned graduate degrees in government and international relations at Harvard University (1928, 1934) and studied in England and South Africa. In 1928 he joined the faculty of Howard University, Washington, D.C., where he set up a department of political science. Meanwhile, he traveled through French West Africa on a Rosenwald field fellowship, studying the administration of French Togoland, a mandated area, and Dahomey, a colony. He later did postdoctoral research at Northwestern University, Evanston, Ill., and at the London School of Economics before returning to Africa for further studies in colonial policy. Between 1938 and 1940 he collaborated with Gunnar Myrdal, the Swedish sociologist, in the monumental study of U.S. race relations, published as An American Dilemma in 1944.

During World War II Bunche served in the U.S. War Department, the Office of Strategic Services, and the State Department. He was active in the preliminary planning for the United Nations at the San Francisco Conference of 1945 and in 1947 joined the permanent UN Secretariat in New York as director of the new Trusteeship Department.

Asked by Secretary General Trygve Lie to aid a UN special committee appointed to negotiate a settlement between warring Palestinian Arabs and Jews, he was thrust unexpectedly into the principal role when the chief mediator, Count Folke Bernadotte, was assassinated in 1948. Bunche finally negotiated armistices between February and May 1949.

Elevated in 1955 to the post of undersecretary and two years later to undersecretary for special political affairs, Bunche became chief