Vietnam War remained in the field for four days. Tellingly, South Vietnamese forces were again defeated in June 1965 at the Battle of Đồng Xoài. On 8 March 1965, 3,500 U.S. Marines were unilaterally dispatched to South Vietnam. This marked the beginning of the American ground war. U.S. public opinion overwhelmingly supported the deployment. The Marines' initial assignment was defensive. The first deployment of 3,500 in March 1965 was increased to nearly 200,000 by December. The U.S. military had long been schooled in offensive warfare. Regardless of political policies, U.S. commanders were institutionally and psychologically unsuited to a defensive mission. General William
1961 in the Vietnam War of the U.S. Army to respond to Kennedy's emphasis on developing a greater capability in counterinsurgency, although the U.S. Military Assistance Advisory Group began providing counterinsurgency training to the South Vietnamese army (ARVN) and other security forces. The Kennedy Administration debated internally about introducing U.S. combat troops into South Vietnam, but Kennedy decided against ground soldiers. The CIA began assisting Montagnard irregular forces, American pilots began flying combat missions to support South Vietnamese ground forces, and Kennedy authorized the use of herbicides (Agent Orange) to kill vegetation near roads threatened by the Viet Cong. By the end of the year,