President Richard Nixon announces that 50,000 additional U.S. troops will be pulled out of South Vietnam by April 15, 1970. This was the third reduction since the June Midway conference, when Nixon announced his Vietnamization program.
Under the Vietnamization program, the South Vietnamese forces would receive intensified training and new equipment so they could gradually assume overall responsibility for the war. Concurrent with this effort, Nixon announced that he would begin to bring U.S. troops home. This third increment would bring the total reductions to 115,000. By January 1972, there were only around 70,000 U.S. troops left in South Vietnam.
Noting the steady withdrawal of American forces, the North Vietnamese decided to launch a massive invasion of South Vietnam in March 1972. The South Vietnamese forces, supported by American advisers and U.S. airpower, reeled under the onslaught but ultimately prevailed, holding on despite overwhelming odds. After much posturing and many lengthy negotiations (with additional "motivation" contributed by Nixon's bombing of North Vietnam in December 1972), National Security Advisor Henry Kissinger and his North Vietnamese counterpart, Le Duc Tho, hammered out a peace agreement. A cease-fire went into effect on January 27, 1973.
The war was over for the United States, but fighting soon resumed between North and South Vietnam. The South Vietnamese held out for nearly two years, but succumbed when the United States cut off all military support. When the North Vietnamese launched a new offensive in March 1975, South Vietnam fell in just 55 days.