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
Australian Army Training Team Vietnam later. Serong would later be seconded, and in one capacity or another would remain in Vietnam until the fall of Saigon in 1975, serving as a senior advisor to both the US and South Vietnamese governments. On arrival, the unit joined a large group of US advisors and were dispersed across South Vietnam in small groups. Three groups were dispatched to South Vietnam's northern provinces, training members of the Army of the Republic of Vietnam (ARVN) at the National Training Centre at Dong Da and South Vietnamese Regional Forces (RF) at Hiep Khanh, while a fourth was based at the