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.

The Krulak–Mendenhall mission was a fact-finding expedition dispatched by the Kennedy administration to South Vietnam in early September 1963. The stated purpose of the expedition was to investigate the progress of the war by the South Vietnamese regime and its US military advisers against the Viet Cong insurgency. The mission was led by Victor Krulak and Joseph Mendenhall. Krulak was a major general in the United States Marine Corps, while Mendenhall was a senior Foreign Service Officer experienced in dealing with Vietnamese affairs.