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
1947–50 in the Vietnam War communist activity was coordinated worldwide. Thus, the attack on South Korea caused the U.S. to become more concerned about the Việt Minh insurgency in Vietnam. Việt Minh forces were estimated to have grown to 250,000 personnel, including 120,000 in regular units organized into divisions. The remaining troops were regional and popular and primarily concerned with defense and security. An estimated 15,000 Chinese, in both Vietnam and China, assisted the Việt Minh with training, technicians, and advisers. The French had about 150,000 soldiers in Vietnam. The pro-French Vietnamese army numbered about 16,000 The first U.S. military advisers to Vietnam arrived in