Operation Lam Son was planned as a pre-emptive attack against the North Vietnamese People’s Army of Vietnam, which was thought to be moving supplies down the Ho Chi Minh trail, which ran along the Laos/Cambodia and Vietnam borders, ready for an offensive into South Vietnam towards the end of the Laotian dry season. The objective of the offensive was for the Army of the Republic of Vietnam to push west along Route 9 towards the town of Tchepone, thought to be in the vicinity of a number of PAVN supply bases. US Infantry had cleared routes towards the border for the ARVN under Operation Dewey Canyon II. The ARVN offensive began on 8 February but the quick thrust west was delayed by hesitation over securing the flank of the attack. This allowed PAVN reinforcements to move into the area and ultimately resulted in the failure to fulfil the objectives of the operation, despite air drops of ARVN troops, which allowed for a brief occupation of Tchepone.