Produced by the U.S. Air Force, this Project CHECO report on Lam Son 719 is a cocise and well documented review of the South Vietnamese incursion into Laos in February and March 1971, and is a narrative of what was one of the most significant military actions in Southeast Asia since the 1968 Tet Offensive. Lam Son 719 was the first operation of its kind, a cross-border raid in which large units of South Vietnamese ground forces operated independently without U.S. Army ground advisors, but with almost complete dependence upon U.S. air support. Lam Son 719 showed that a large Vietnamese ground force, which had remained on the sidelines for years, could move into the enemy stronghold given U.S. air support. This was a critical test of its capability, a test which would have a great impact upon plans for American withdrawal from Vietnam.