On November 2, 1963, South Vietnamese military officers murdered their president of nine years, Ngo Dinh Diem, and took control of the nation's government. The American hand was invisible at the time, but regime change came to fruition only because of active encouragement by the U.S. ambassador, who believed that a coup would improve South Vietnam's war effort. In the months that followed, however, South Vietnam experienced a succession of coups and countercoups, whose debilitating effects drew