The Battle of Lang Vei (Vietnamese: Trận Làng Vây) began on the evening of 6 February 1968 and concluded during the early hours of 7 February, in Quảng Trị Province, South Vietnam. Towards the end of 1967, the 198th Tank Battalion of the People's Army of Vietnam's (PAVN) 202nd Armored Regiment received instructions from the North Vietnamese Ministry of Defense to reinforce the 304th Division as part of the Route 9–Khe Sanh Campaign. After an arduous journey down the Ho Chi Minh trail in January 1968, the 198th Tank Battalion linked up with the 304th Division for an offensive along Highway 9, which stretched from the Laotian border through to Quảng Trị Province. On 23 January, the 24th Regiment attacked the small Laotian outpost at Bane Houei Sane, under the control of the Royal Laos Army BV-33 "Elephant" Battalion. In that battle, the 198th Tank Battalion failed to reach the battle on time because its crews struggled to navigate their tanks through the rough local terrain. However, as soon as the PT-76 tanks of the 198th Tank Battalion turned up at Bane Houei Sane, the Laotian soldiers and their families retreated into South Vietnam.
After Bane Houei Sane was captured, the 24th Regiment prepared for another attack which targeted the U.S. Special Forces Camp at Lang Vei, manned by Detachment A-101 of the 5th Special Forces Group and indigenous Civilian Irregular Defense Group (CIDG) forces. On 6 February, the 24th Regiment, again supported by the 198th Tank Battalion, launched their assault on Lang Vei. Despite artillery and air support, the U.S.-led forces conceded ground and the PAVN quickly dominated their positions. By the early hours of 7 February the command bunker was the only position still held by Allied forces. To rescue the American survivors inside the Lang Vei Camp, a counterattack was mounted, but the Laotian soldiers who formed the bulk of the attack formation refused to fight the PAVN. Later on, U.S. Special Forces personnel were able to escape from the camp, and were rescued by a U.S. Marine task force from Khe Sanh Combat Base.
Background North Vietnam The task of capturing Lang Vei was entrusted to the PAVN's 24th Regiment, 304th Division, led by Colonel Le Cong Phe. The regiment was to be supported by the 2nd Battalion (part of the 101D Regiment, 325th Division), the 2nd Artillery Battalion (part of the 675th Artillery Regiment), one 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 on 4 May 1967. Even though the PAVN attack was repelled, damage to the camp was extensive. Since the original site lacked good observation and fields of fire beyond the barbed-wire perimeter, the 5th Special Forces Group commander decided to move the camp to a more suitable area, about 1,000 meters to the west. The new camp, on Highway 9 about to the west of Khe Sanh, was completed in 1967.
In 1967, Captain Franklin C. Willoughby assumed command of Detachment A-101 at Lang Vei, which had a tactical area of responsibility of , and was one of nine operational CIDG camps in I Corps Tactical Zone. From Lang Vei, U.S Special Forces personnel worked jointly with a 14-man Army of the Republic of Vietnam (ARVN) special forces contingent and six interpreters; they were responsible for border surveillance, interdiction of enemy infiltration and assistance in the Revolutionary Development Program. To accomplish those tasks Willoughby had one Montagnard company, three South Vietnamese rifle companies and three combat reconnaissance platoons at his disposal. Early in January 1968, Detachment A-101 received reinforcements in the form of a Mobile Strike Force Company, consisting of 161 Hre tribesmen, along with six U.S. Special Forces advisors. Elements of this Mobile Strike Force Company operated from a fortified bunker about 800 meters west of the camp, which served as an observation post. During the day the Hre tribesmen of the Mobile Strike Force conducted patrols; at night they took up ambush positions in the vicinity of the camp.
Prior to the battle, Willoughby placed Company 101 of 82 Bru Montagnard tribesmen, on the northeastern flank of the camp, with the 3rd Combat Reconnaissance Platoon positioned just behind it. Company 104 was placed in the southern end of the camp; Company 102, consisting of 42 men, was positioned at the opposite end about 450 meters to the west, while the 43-man Company 103 was positioned further south. The 1st and 2nd Combat Reconnaissance Platoons were placed at the northern and southern perimeters respectively, about 200 meters apart. Individually, the CIDG personnel carried M1 and M2 carbines with nearly 250,000 rounds of ammunition, and each company was also equipped with one 81 mm mortar. Among heavy weapons, there were two 106mm recoilless rifles, two 4.2-inch mortars and nineteen 60 mm mortars positioned around the camp. For close-in support, the CIDG personnel were furnished with 100 disposable M-72 anti-tank weapons. Antitank mines were requested, but were denied. If necessary, Willoughby could also request support from at least two rifle companies from the 26th Marine Regiment at Khe Sanh, along with artillery support from other locations within range.
Following the construction of the new camp site west of Lang Vei, Willoughby and his CIDG soldiers concentrated their efforts on strengthening the camp's defenses, and they made relatively few contacts with the PAVN. However, unbeknownst to Willoughby, the PAVN 304th Division had assembled on the battlefield, reinforced by the 198th Tank Battalion, with the following orders: the 66th Regiment was given the task of capturing Khe Sanh village, part of Hướng Hóa District, to begin their "Route 9-Khe Sanh Campaign"; the 24th Regiment was ordered to destroy the enemy strongholds of Ban Houei Sane and Lang Vei; the 9th Regiment was ordered to destroy any reinforcements that might try to relieve those bases areas. From December 1967, CIDG soldiers operating from Lang Vei began to report more frequent contacts with the PAVN. By mid-January, U.S. military intelligence also reported movements of PAVN formations across the Xe Pone River from Laos into South Vietnam. At the same time, the PAVN began to harass the Lang Vei Camp with mortar and artillery fire at least two or three times a week, and PAVN patrols probed the camp's perimeters. 3rd Marine Division intelligence estimated the combat strength of PAVN and Viet Cong forces in the Vietnamese Demilitarized Zone area during this period was 40,943 troops.
Preliminary attacks On 21 January 1968, the PAVN 66th Regiment began its attack on Khe Sanh village, seat of the Hướng Hóa local government. At that time, Khe Sanh village was defended by the ARVN Regional Force 915th Company and the U.S. Marines Combined Action Company Oscar. Throughout the night, the combined U.S and South Vietnamese forces held their position, but at dawn U.S. soldiers on the ground called in air strikes and artillery support from the Khe Sanh Combat Base. Fighting in and around Khe Sanh village continued throughout the day and into the following night, and was finally captured by the PAVN at 09:30 on 22 January. At 11:00 Colonel David E. Lownds ordered Company D, 1st Battalion, 26th Marines, to relieve the defenders inside Khe Sanh village, but reversed his orders after second thoughts about PAVN ambushes. Later, the ARVN Regional Force 256th Company was destroyed by the PAVN 9th Regiment as it marched to Khe Sanh village. The PAVN 66th Regiment paid a heavy price for their victory with 154 killed and 496 wounded.
On the evening of 23 January, one day after the fall of Khe Sanh village, the PAVN 304th Division moved against their next target, the small Laotian outpost at Ban Houei Sane. Prior to 1968, Laotian forces at Ban Houei Sane had played an important role in the war, watching PAVN infiltration into South Vietnam from a section of the Ho Chi Minh Trail running through Laos. The outpost was manned by 700 Laotian soldiers of BV-33 "Elephant" Battalion, Royal Laos Army, led by Lieutenant Colonel Soulang Phetsampou. As night fell, the PAVN 3rd Battalion, 24th Regiment attacked the outpost. The 198th Tank Battalion, which was tasked with supporting the 24th Regiment, was delayed as their tank crews tried to navigate their PT-76 amphibious tanks through the rough local terrain. However, confusion quickly descended on the Laotian defenders as the PT-76 tanks turned up outside their outpost. After three hours of fighting, Lt. Col. Phetsampou decided to abandon his outpost, so he radioed the Lang Vei Camp and requested helicopters to evacuate his men and their families. However, as helicopters were unavailable, the Laotians decided to move eastward by foot along Highway 9, in an attempt to reach Lang Vei just across the border in South Vietnam.