Vietnamization and American withdrawal, 1969–1973

During the 1968 presidential election, Richard M. Nixon promised "peace with honor". His plan was to build up the ARVN, so that they could take over the defense South Vietnam (the Nixon Doctrine). The policy became known as Vietnamization. This unfortunate term implied, that to date, only Americans had been dying in the conflict.

Nixon also pursued negotiations. Creighton Abrams shifted to smaller operations, aimed at NLF logistics, with better use of firepower and more cooperation with the ARVN. There was increased openness with the media. Nixon also began to pursue détente with the Soviet Union and rapprochement with China. This policy helped to decrease global tensions. Détente led to nuclear arms reduction on the part of both superpowers. But Nixon was disappointed that China and the Soviet Union continued to supply the North Vietnamese with aid. In September, 1969, Ho Chi Minh died at the age of seventy-nine.

The anti-war movement was gaining strength in the US. Nixon appealed to the "Silent Majority" of Americans to support the war. But revelations of the My Lai Massacre, in which U.S. forces went on a rampage and killed civilians, including women and children, provoked national and international outrage.

Prince Norodom Sihanouk had proclaimed the neutrality of Cambodia since 1955. "We are neutral," he noted, "in the same way Switzerland and Sweden are neutral." The PAVN/NLF, however, used Cambodian soil as a base. Sihanouk tolerated their presence, because he wished to avoid being drawn into a wider regional conflict. Under pressure from Washington, however, he changed this policy in 1969. The PAVN/NLF were no longer welcome. President Nixon took the opportunity to launch a massive secret bombing campaign, called Operation Menu, against their sanctuaries along the border. This violated a long succession of pronouncements from Washington, supporting Cambodian neutrality. Richard Nixon wrote to Prince Sihanouk in April, 1969, assuring him that the United States respected "the sovereignty, neutrality and territorial integrity of the Kingdom of Cambodia …" Over 14 months, however, approximately 2,750,000 tons of bombs were dropped, more than the total dropped by the Allies in World War II. The bombing was hidden from the American public. In 1970, Prince Sihanouk was deposed by pro-American general Lon Nol. The country's borders were closed, and the U.S. and ARVN launched incursions into Cambodia to attack PAVN/NLF bases and buy time for South Vietnam. The coup against Sihanouk and U.S. bombing, destabilized Cambodia and increased support for the Kmer Rouge.

The invasion of Cambodia sparked nationwide U.S. protests. Four students were killed by National Guardsmen at Kent State University. The reaction to the incident by the Nixon administration was seen as callous and indifferent. The Kent State shootings shocked the world.

In 1971, the Pentagon Papers were leaked to the New York Times. The top-secret history of U.S. involvement in Vietnam, commissioned by the Department of Defense, detailed a long series of public deceptions. The Supreme Court ruled that its publication was legal.

The ARVN launched Operation Lam Son 719, aimed at cutting the Ho Chi Minh trail in Laos. The offensive was a clear violation of Laotian neutrality[99], which neither side respected in any event. Laos had long been the scene of a Secret War. After meeting resistance, ARVN forces retreated in a confused rout. They fled along roads littered with their own dead. When they ran out of fuel, soldiers abandoned their vehicles and attempted to barge their way on to American choppers sent to evacuate the wounded. Many ARVN soldiers clung to helicopter skids in a desperate attempt to save themselves. U.S. aircraft had to destroy abandoned equipment, including tanks, to prevent them from falling into enemy hands. Half of the invading ARVN troops were either captured or killed. The operation was a fiasco and represented a clear failure of Vietnamization. As Stanley Karnow noted "the blunders were monumental … The (South Vietnamese) government's top officers had been tutored by the Americans for ten or fifteen years, many at training schools in the United States, yet they had learned little."

In 1971, Australia and New Zealand withdrew their soldiers. The U.S. troop count was further reduced to 196,700, with a deadline to remove another 45,000 troops by February 1972. As peace protests spread across the United States, disillusionment grew in the ranks. Drug use increased, race relations grew tense and the number of soldiers disobeying officers rose. Fragging, or the murder of unpopular officers with fragmentation grenades, increased.

Vietnamization was again tested by the Easter Offensive of 1972, a massive conventional invasion of South Vietnam. The PAVN/NLF quickly overran the northern provinces and in co-ordination with other forces, attacked from Cambodia, threatening to cut the country in half. U.S. troop withdrawals continued. But American airpower came to the rescue with Operation Linebacker and the offensive was halted. However, it became clear that without American airpower South Vietnam could not survive. The last remaining American ground troops were withdrawn in August. But a force of civilian and military advisors remained in place.

The war was the central issue of the 1972 presidential election. Nixon's opponent, George McGovern, campaigned on a platform of withdrawal from Vietnam. Nixon's National Security Adviser, Henry Kissinger, continued secret negotiations with North Vietnam's Le Duc Tho. In October 1972, they reached an agreement. However, South Vietnamese President Thieu demanded massive changes to the peace accord. When North Vietnam went public with the agreement's details, the Nixon administration claimed that the North was attempting to embarrass the President. The negotiations became deadlocked. Hanoi demanded new changes. To show his support for South Vietnam and force Hanoi back to the negotiating table, Nixon ordered Operation Linebacker II, a massive bombing of Hanoi and Haiphong. The offensive destroyed much of the remaining economic and industrial capacity of North Vietnam. Simultaneously Nixon pressured Thieu to accept the terms of the agreement, threatening to conclude a bilateral peace deal and cut off American aid. Popularly known as the Christmas Bombings, Operation Linebacker II provoked a fresh wave of anti-war demonstrations.

On 15 January 1973, Nixon announced the suspension of offensive action against North Vietnam. The Paris Peace Accords on 'Ending the War and Restoring Peace in Vietnam' were signed on 27 January, 1973, officially ending direct U.S. involvement in the Vietnam War. A cease-fire was declared across South Vietnam, but North Vietnamese forces were allowed to remain on South Vietnamese territory. U.S. POWs were released. The agreement guaranteed the territorial integrity of Vietnam and, like the Geneva Conference of 1954, called for national elections in the north and south. The Paris Peace Accords stipulated a sixty day period for the total withdrawal of U.S. forces. "This article," noted Peter Church, "proved … to be the only one of the Paris Agreements which was fully carried out."

The ARVN was supplied with hundreds of millions of dollars of new equipment. It became the fourth largest fighting force in the world. Nixon promised Thieu that he would use airpower to support his government. The growing Watergate scandal and an American public tired of the war, however, made it impossible to keep his promise. The balance of power shifted decisively in North Vietnam's favor.