Tet Offensive in South Vietnam. Although neither of these offensives accomplished any military objectives, the surprising capacity of an enemy to even launch such an offensive convinced many in the U.S. that victory was impossible. A vocal and growing peace movement centered on college campuses became a prominent feature as the counter culture of the 1960s adopted a vocal anti-war position. Especially unpopular was the draft that threatened to send young men to fight in the jungles of Southeast Asia. Elected in 1968, U.S. President Richard M. Nixon began a policy of slow disengagement from the war. The goal was to gradually build up the South Vietnamese Army so that it could fight the war on its own. This policy became the cornerstone of the so-called "Nixon Doctrine." As applied to Vietnam, the doctrine was called "Vietnamization." The goal of Vietnamization was to enable the South Vietnamese army to increasingly hold its own against the NLF and the North Vietnamese Army. On October 10, 1969, Nixon ordered a squadron of 18 B-52s loaded with nuclear weapons to race to the border of Soviet airspace in order to convince the Soviet Union that he was capable of anything to end the Vietnam War. The morality of U.S. conduct of the war continued to be an issue under the Nixon presidency. In 1969, it came to light that Lt. William Calley, a platoon leader in Vietnam, had led a massacre of Vietnamese civilians a year earlier. In 1970, Nixon ordered secret military incursions into Cambodia in order to destroy NLF sanctuaries bordering on South Vietnam. The U.S. pulled its troops out of Vietnam in 1973, and the conflict finally ended in 1975 when the North Vietnamese took Saigon, now Ho Chi Minh City. The war exacted a huge human cost in terms of fatalities (see Vietnam War casualties). 195,000–430,000 South Vietnamese civilians died in the war. 50,000–65,000 North Vietnamese civilians died in the war. The Army of the Republic of Vietnam lost between 171,331 and 220,357 men during the war. The official US Department of Defense figure was 950,765 communist forces killed in Vietnam from 1965 to 1974. Defense Department officials concluded that these body-count figures need to be deflated by 30 percent. In addition, Guenter Lewy assumes that one-third of the reported "enemy" killed may have been civilians, concluding that the actual number of deaths of communist military forces was probably