When President Richard M. Nixon took office in January 1969, he chose former political science professor Henry A. Kissinger as his national security advisor. Kissinger saw Vietnam as a mistake and pushed for disengagement. Not long into his term, Nixon announced a new policy of Vietnamization to gradually withdraw the more than 500,000 American soldiers from Vietnam and return control of the war to the South Vietnamese ARVN.
Nixon did not intend to abandon Saigon fully—the United States would still fund, supply, and train the ARVN—but hoped that slow troop withdrawals would appease voters at home and reduce the number of troop casualties in the field. He also announced the Nixon Doctrine, in which he proclaimed that the United States would honor its current defense commitments but that it would not commit troops anywhere else.
In September 1969, the North Vietnamese leader Ho Chi Minh died. He was replaced by Le Duan, who became the new head of the North Vietnamese Communist Party. Although North Vietnam lost a powerful ideological figure in Ho, his death did not weaken the Vietnamese nationalist cause.
Vietnamization and the Nixon Doctrine did reduce combat casualties but also turned U.S. foreign policy upside down. In declaring that the United States would no longer commit troops to stop Communist revolutions abroad, Nixon effectively revoked Eisenhower’s, Kennedy’s, and Johnson’s policies of using the U.S. military to prevent Communism from spreading. Although his predecessors had sent troops to fight Soviet influence in the farthest corners of the world, Nixon believed that the political cost of more dead U.S. servicemen was simply too great.
With Vietnamization under way, Nixon and Kissinger still had a few tricks up their sleeves. While reducing U.S. personnel in Vietnam slightly in 1969, they also sought to defeat the North Vietnamese by destroying their supply lines and base camps in neighboring Cambodia. Although Cambodia was officially a neutral nation, the NVA had long used its territory to run weapons and troops, circumventing the U.S. soldiers, bombers, and raiding parties that were operating in Vietnamese territory.
In the spring of 1970, Nixon authorized a series of bombing raids in Cambodia and sent both U.S. and ARVN troops across the border, all without the consent or even awareness of Congress. When the secret Cambodian campaign was revealed in a New York Times exposé in May 1970, it sent shock waves through the uninformed Congress and the American public. Renewed public outcry and waves of protests eventually convinced Nixon to rescind the order that summer. Nonetheless, he authorized a similar action in March 1971, secretly sending ARVN forces across the border into Laos.