Vietnam ground combat operations in 1965, and at their peak they numbered more than 500,000. The US also engaged in a sustained aerial bombing campaign. Meanwhile, China and the Soviet Union provided North Vietnam with significant material aid and 15,000 combat advisers. Communist forces supplying the Việt Cộng carried supplies along the Hồ Chí Minh trail, which passed through the Kingdom of Laos. The communists attacked South Vietnamese targets during the 1968 Tết Offensive. Although the campaign failed militarily, it shocked the American establishment, and turned US public opinion against the war. During the offensive, communist troops massacred over 3,000 civilians
Joint warfare in South Vietnam, 1963–1969 Vietnam, and the 173rd Airborne Brigade for the Bien Hoa/Vũng Tàu area near Saigon. Early, CINCPAC had objected to the use of the 173rd, since it was the primary strategic reserve for Pacific Command. Westmoreland, in early June, saw the situation as close to collapse without a major commitment of ground troops, in addition to the ARVN. This triggered several weeks of intense debate among the President's close civilian advisers, with McNamara controlling all direct military input to the process. There were two drivers among the inner circle. First, some, but not all, were fervent believers in the containment doctrine,