The McNamara–Taylor mission was a 10-day fact-finding expedition to South Vietnam in September 1963 by the Kennedy administration to review progress in the battle by the Army of the Republic of Vietnam and its American advisers against the communist insurgency of the National Liberation Front of South Vietnam. The mission was led by US Secretary of Defense Robert McNamara and General Maxwell D. Taylor, the Chairman of the Joint Chiefs of Staff.

Roger Hilsman Jr. was an American soldier, government official, political scientist, and author. He saw action in the China-Burma-India Theater of World War II, first with Merrill's Marauders, getting wounded in combat, and then as a guerilla leader for the Office of Strategic Services. He later became an aide and adviser to President John F. Kennedy, and briefly to President Lyndon B. Johnson, in the U.S. State Department while he served as Director of the Bureau of Intelligence and Research in 1961 to 1963 and Assistant Secretary of State for Far Eastern Affairs in 1963 to 1964.