Operation Dewey Canyon II ends, but U.S. units continue to provide support for South Vietnamese army operations in Laos. Operation Dewey Canyon II began on January 30 as the initial phase of Lam Son 719, the South Vietnamese invasion of Laos that was to commence on February 8. The purpose of the South Vietnamese operation was to interdict the Ho Chi Minh Trail, advance to Tchepone in Laos, and destroy the North Vietnamese supply dumps in the area.
In Dewey Canyon II, the vanguard of the U.S. 1st Brigade, 5th Infantry Division, an armored cavalry/engineer task force, cleared the road from Vandegrift Combat Base (southwest of Cam Lo in the region south of the DMZ) along highway Route 9 toward Khe Sanh. The area was cleared so that 20,000 South Vietnamese troops could reoccupy 1,000 square miles of territory in northwest South Vietnam and mass at the Laotian border in preparation for the invasion of Laos. In accordance with a U.S. congressional ban, U.S. ground forces were not to enter Laos. Instead, the only direct U.S. support permitted was long-range cross-border artillery fire, fixed-wind air strikes, and 2,600 helicopters to airlift Saigon troops and supplies.
