Roughly 20,000 South Vietnamese troops crossed into Laos in the largest test yet of 'Vietnamization,' the U.S. policy of shifting ground combat to South Vietnamese forces while American troops withdrew. U.S. law barred American ground troops from entering Laos, so U.S. involvement was limited to helicopters, artillery, and airstrikes.
The operation aimed to sever the Ho Chi Minh Trail, the sprawling network of jungle roads and paths through Laos and Cambodia that North Vietnam used to funnel troops and supplies south. President Nixon saw it as the ultimate proof that Vietnamization could work—that South Vietnam's army, propped up by American airpower, could fight and win without American infantry.
It did not go well. North Vietnamese forces, expecting the incursion, met the South Vietnamese with heavy armor and artillery. American helicopter crews flew some of the most dangerous missions of the entire war ferrying troops and supplies under intense anti-aircraft fire, and hundreds of aircraft were damaged or destroyed.
By the time South Vietnamese forces withdrew in disarray in March, the operation had exposed the fragility of Vietnamization rather than confirming its success. Television images of panicked South Vietnamese soldiers clinging to helicopter skids undercut Nixon's optimistic narrative back home and further eroded American public support for the war.
Key people: Richard Nixon, Nguyen Van Thieu