On the outskirts of the village of Ban Dong on Route 9 sit two rusting American tanks, all that remains of a massive invasion and series of battles that have become a mere footnote in the history of the decade-long American military debacle in Indochina. In 1971 President Nixon, anticipating a massive campaign by North Vietnamese troops against South Vietnam the following year (which happened to be an election year in the US), ordered an attack on the Ho Chi Minh Trail to cut off supplies to communist forces. Although a congressional amendment had been passed the previous year prohibiting US ground troops from crossing the border from Vietnam into Laos and Cambodia, the US command saw it as an opportunity to test the strengths of Vietnamization, the policy of turning the ground war over to the South Vietnamese. For the operation, code-named Lam Son 719, it was decided that ARVN (Army of the Republic of Vietnam) troops were to invade Laos and block the trail with the backing of US air support. The objective was Xepon, a town straddled by the Trail, which was some 30–40km wide at this point. Nixon’s national security adviser, Henry Kissinger, was later to lament that “the operation, conceived in doubt and assailed by scepticism, proceeded in confusion”. In early February 1971, ARVN troops and tanks pushed across the border at Lao Bao and followed Route 9 into Laos. Like a caterpillar trying to ford a column of red ants, the South Vietnamese troops were soon engulfed by North Vietnamese (NVA) regulars, who were superior in number. Ordered by President Thieu of South Vietnam to halt if there were more than 3000 casualties, ARVN officers stopped halfway to Xepon and engaged the NVA in a series of battles that lasted over a month. US air support proved ineffectual, and by mid-March scenes of frightened ARVN troops drastically retreating were being broadcast around the world. In an official Lao account of the battle, a list of “units of Saigon puppet troops wiped out on Highway 9” included four regiments of armoured cavalry destroyed between the Vietnam border and Ban Dong.