The Constitution makes the president commander in chief of the armed forces, but gives Congress the power to declare war, sometimes creating tension between the two branches. Senate Foreign Relations Committee Chairman J. William Fulbright was an early supporter of America’s efforts against the spread of Communism in Southeast Asia. He supported the Gulf of Tonkin Resolution in 1964, authorizing American military retaliation against North Vietnamese attacks. When President Lyndon Johnson used the resolution as the equivalent of a declaration of war, Senator Fulbright launched a series of hearings to explore the reasons for America’s escalating participation in the conflict. Both supporters and critics of the Vietnam War testified in hearings that continued until 1972. The often-televised investigation promoted a national debate over the Vietnam War and gave encouragement to the growing antiwar movement.