In August 1964, in response to American and GVN espionage along its coast, the DRV launched a local and controlled attack against the C. Turner Joy and the U.S.S. Maddox, two American ships on call in the Gulf of Tonkin. The first of these attacks occurred on August 2, 1964. A second attack was supposed to have taken place on August 4, although Vo Nguyen Giap, the DRV's leading military figure at the time, and Johnson's Secretary of Defense Robert S. McNamara have recently concluded that no second attack ever took place. In any event, the Johnson administration used the August 4 attack as political cover for a Congressional resolution that gave the president broad war powers. The resolution, now known as the Gulf of Tonkin Resolution, passed both the House and Senate with only two dissenting votes (Senators Morse of Oregon and Gruening of Alaska). The Resolution was followed by limited reprisal air attacks against the DRV.