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
Vietnam War saw extensive action during the Vietnam War, and over 600 were deployed with US Forces. Ground forces also had access to B-52 and F-4 Phantom II and others to launch napalm, white phosphorus, tear gas and chemical weapons, precision-guided munition and cluster bombs. The Vietnam War was the first conflict where U.S. forces had secure voice communication equipment available at the tactical level. The National Security Agency ran a crash program to provide U.S. forces with a family of security equipment, code named NESTOR, fielding 17,000 units initially; eventually 30,000 units were produced. However, limitations of the units, including poor