tank company (part of the 198th Tank Battalion, 203rd Armored Regiment), two sapper companies, one anti-aircraft gun company, and one flamethrower platoon. One of the most important features of the PAVN formation were the elements of the 203rd Armoured Regiment; the "Route 9-Khe Sanh Campaign" marked the first time the PAVN deployed its armored forces on the battlefield. In 1964, soldiers of the PAVN's first armored unit—the 202nd Armored Regiment—was sent into South Vietnam without their T-34 medium tanks, because their prime mission was to learn enemy armor tactics in order to prepare for future missions. On 22 June 1965, the North Vietnamese Ministry of Defense passed Resolution 100/QD-QP, to establish the 203rd Armored Regiment and Resolution 101/QD-QP to create an Armored Force Command. For PAVN commanders, the creation of an independent armored force command represented a significant milestone in the development of their army, because it enabled them to respond to the circumstances on the battlefield with a modern armored force. To prepare for their upcoming mission, the 203rd Armored Regiment undertook a series of combined-arms training with infantry and artillery units in different types of terrain, in order to operate in Vietnam's rough mountainous and jungle conditions. On 5 August 1967, the Ministry of Defense ordered the 203rd Armored Regiment to form a sub-unit, namely the 198th Tank Battalion equipped with 22 PT-76 amphibious tanks, to bolster the strength of the 304th Division in South Vietnam. From their base in Luong Son, Hòa Bình Province, the 198th Tank Battalion began their arduous journey down the Ho Chi Minh Trail under constant U.S. air-strikes. In January 1968, the 198th Tank Battalion arrived on the field where it joined the 304th Division for an attack on the Laotian outpost of Ban Houei Sane. United States/South Vietnam The Lang Vei Special Forces Camp was placed under the control of the United States Army's Detachment A-101, Company C, 5th Special Forces Group, to train and equip locally recruited Vietnamese through the CIDG program. Detachment A-101 had originally been established in July 1962 at Khe Sanh. In 1966, Detachment A-101 moved to its first site near the village of Lang Vei, when the United States Marines took control of Khe Sanh Combat Base as part of an American military build-up in South Vietnam's northern provinces. However, the first camp at Lang Vei proved to be only temporary, as the PAVN attacked the camp