Lam Son 719 - Critique
"LAM SON 719 demonstrated what can happen when a large operation is insufficiently coordinated: conflicting orders were issued, the limited amount of armor was misused, unit leadership broke down, and the strength of the enemy was either overlooked or disregarded. That the North Vietnamese knew of the attack beforehand was evident in their placement of artillery, mortars, and antiaircraft weapons in the area of operations chosen by the South Vietnamese. Enemy troop buildups north of the Demilitarized Zone were noted as well as an increase in the movement of supplies along the trails." pg 187, Mounted Combat In Vietnam, by General Donn A. Starry, Vietnam Studies, Department of the Army, Washington, D.C., 1989
The information presented below was found at:
CMH Online is provided as a public service by the U.S. Army Center of Military History.
Information presented on CMH Online is considered public information and may be distributed or copied for non-commerical purposes. Use of appropriate byline/photo/image credits is requested.


Lam Son 719

After U.S. units withdrew from Cambodia in June of 1970, the face of the war in Vietnam changed significantly. The remainder of the year was a time of small and infrequent enemy infantry attacks, fire attacks, and chance engagements. American forces directed their efforts toward strengthening the South Vietnamese forces and pacification of the South Vietnamese people. Mainly because of the Cambodian incursions and the resulting disruption of the enemy's supply and training bases, both causes advanced rapidly.

American forces were relocated in bases farther from the border, and the South Vietnamese Army assumed responsibility for the security of the border.10 For the first time in many years, the South Vietnamese had to shoulder the larger share of combat operations- a dramatic change. South Vietnamese forces moved toward self-sufficiency and achieved considerable success. Regional Forces and Popular Forces took over many of those defensive operations that had long tied down the Vietnamese Army. And as U.S. troops were withdrawn from Vietnam, South Vietnamese units began large-scale operations on their own.

By late 1971, after extensive destruction of enemy supplies during the Cambodian incursions, enemy logistical and troop movements along the Laotian trails in the north increased dramatically. This fact and the impending withdrawal of U.S. air support prompted the South Vietnamese Army to attack into Laos and strike the enemy trail network at a junction near Tchepone. (Map 15) The South Vietnamese planned to commit two reinforced army divisions and their Marine division to this operation, LAM Sort 719, commencing early in 1971. The planners considered this attack the last chance for cross-border operations using U.S. air support. They also believed that the operation, if successful, could


prevent a major enemy offensive for at least another year and take some pressure off the Cambodian Army to the south.

LAM SON 719 demonstrated what can happen when a large operation is insufficiently coordinated: conflicting orders were issued, the limited amount of armor was misused, unit leadership broke down, and the strength of the enemy was either overlooked or disregarded. That the North Vietnamese knew of the attack beforehand was evident in their placement of artillery, mortars, and antiaircraft weapons in the area of operations chosen by the South Vietnamese. Enemy troop buildups north of the Demilitarized Zone were noted as well as an increase in the movement of supplies along the trails.

Although American ground forces supported LAM SON 719, they were required to remain in South Vietnam. A task force, part of Operation DEWEY CANYON II, consisting of elements of the 1st Battalion, 61st Infantry (Mechanized) ,11 the 1st Battalion, 77th Armor, the 3d Squadron, 5th Cavalry, and Troop A, 4th Squadron, 12th Cavalry, had the mission of establishing logistical bases, keeping Route QL-9 open to the Laotian border, and covering the withdrawal of the South Vietnamese.

At 0400 on 29 January the task force left Quang Tri City along National Highway 9 and by nightfall rolled into Fire Support Base Vandergrift. After a short halt Troop A, 3d Squadron, 5th Cavalry, commanded by Captain Thomas Stewart, and two engineer companies led out on foot at midnight on 29 January. The vehicles were left to move with the main body since Route 9 was known to be in a poor state of repair. A bulldozer led the column with headlights blazing.12 Whenever an obstacle such as a damaged bridge was encountered, a force of two to six cavalrymen and engineers would stop to make repairs while the rest of the team continued. The cavalry troop, joined by its vehicles, arrived at Khe Sanh at 1400 on 1 February, with National Highway 9 opened behind it from Fire Support Base Vandergrift. The next day the road was opened all the way to the border by the 1st Squadron, 1st Cavalry (-) .

As a supplement to this route, the remainder of the 3d Squadron, 5th Cavalry, and elements of the 7th Engineer Battalion con-


MAP 15



RED DEVIL ROAD, an engineering feat that opened enemy areas never before penetrated.


structed a secondary road, known as Red Devil Road and roughly parallel to Route 9, from Fire Support Base Elliott to Khe Sanh. The 3d Squadron, 5th Cavalry, continued operations north of Khe Sanh along Red Devil Road until 7 April.

The South Vietnamese Army Attack

In LAM SON 719, the Vietnamese hoped to disrupt Viet Cong and North Vietnamese supply lines by a combination of airmobile and armor ground attacks on three axes westward into Laos. The main attack was to be conducted along National Highway 9 to Aloui by the airborne division and the 1st Armored Brigade, which would then continue west on order. The South Vietnamese 1st Infantry Division, in a series of battalion-size airmobile assaults, was to establish fire bases on the high ground south of Route 9 to secure the south flank. The South Vietnamese 1st Ranger Group was to conduct airmobile assaults to establish blocking positions and secure the north flank. The Vietnamese Marine division was the I Corps reserve at Khe Sanh. The U.S. 2d Squadron, 17th Cav-



alry, was to locate and destroy antiaircraft weapons, find enemy concentrations, and carry out reconnaissance and security missions, which included the rescue of air crews downed in Laos. The squadron was permitted to go into Laos only one hour before the first airmobile assaults. This constraint precluded early reconnaissance of North Vietnamese antiaircraft positions, and in the beginning limited the air cavalry to screening the landing zones just before the assaults.

The 1st Armor Brigade, with two South Vietnamese airborne battalions and the 11th and 17th Cavalry Regiments, which had fewer than seventeen M41 tanks, crossed the border at 1000 on 8 February and moved nine kilometers west along National Highway 9. Intelligence reports had indicated that the terrain along Route 9 in Laos was favorable for armored vehicles. In reality, Route 9 was a neglected forty-year-old, single-lane road, with high shoulders on both sides and no maneuver room. Moreover, as the units moved forward they discovered the entire area was filled with huge bomb craters, undetected earlier because of dense grass and bamboo. Armored vehicles were therefore restricted to the road.

With armored units moving west on Route 9, the airborne division and the 1st Infantry Division made an assault into landing zones north and south of Route 9. One Ranger battalion came down near Landing Zone Ranger South. As the first troops arrived the air cavalry moved out to reconnoiter the front and flanks, seek-


ing landing areas and destroying antiaircraft positions. But the demand for gunships became heavy as units on the ground encountered North Vietnamese Army forces. In the air cavalry, emphasis shifted to locating enemy troop concentrations and indirect fire weapons that posed an immediate threat to South Vietnamese forces. Thus, long-range reconnaissance was sacrificed for fire support.

The air cavalry screened the 1st Armor Brigade's advance along Route 9 all the way to Aloui, which the brigade reached in the afternoon of 10 February.13 Within three days Vietnamese airmobile forces on the ridgelines to the north and south had moved abreast of Aloui. Since the airborne division was unable to secure Route 9; the 1st Armor Brigade as well as other ground forces had to be resupplied by air for the duration of LAM SON 719.

Enemy reaction to LANs SON 719 was swift and violent. The North Vietnamese had elements of three infantry regiments as well as an artillery regiment and a tank battalion in the area, and quickly brought in eight more infantry regiments and part of a tank regiment. The north flank of the South Vietnamese attack soon came under heavy assault. The Ranger battalion at Landing Zone Ranger North was attacked on 20 February, and elements of the battalion withdraw to Landing Zone Ranger South the next day. In the following days both Ranger South and Landing Zone 31 came under increasing pressure until, on 25 February, the Rangers were evacuated from Ranger South.

As the South Vietnamese command debated whether to continue the drive west, pressure on Landing Zone 31 developed into a coordinated enemy tank-infantry attack with supporting fire from artillery and rockets. Command confusion added to the problems of the Vietnamese forces when conflicting orders from the airborne division and from I Corps headquarters delayed relief of the landing zone by the armored brigade. On 18 February I Corps ordered the 17th Armored Cavalry (-) north from Aloui to reinforce Landing Zone 31. At the same time the airborne division ordered it to stop south of the landing zone and wait to see if the site was overrun. Neither headquarters was on the scene. AS a result of the confusion, the 17th Armored Cavalry, with tanks from the 11th Armored Cavalry, arrived at Landing Zone 31 on 19 February after some airborne elements had been pushed back.

In the first battle between North Vietnamese and South Viet-


namese tanks, Sergeant Nguyen Xuan Mai, a tank commander in the 1st Squadron, 11th Armored Cavalry Regiment, destroyed a North Vietnamese T54 tank.14 The South Vietnamese forces retook a portion of the landing zone by the end of the day. Twenty-two enemy tanks-six T54's and sixteen PT76's-were destroyed, with none of the South Vietnamese M41's lost. Direct and indirect fire continued to pound the airborne troops, and, finally, after six days, the enemy overran the entire landing zone. The 17th Armored Cavalry Regiment and one airborne battalion were pushed to the south.

After Landing Zone 31 was lost, all airborne elements were withdrawn and the 17th Armored Cavalry was isolated southeast of the site. Enemy pressure on the cavalry remained heavy. Attacked at noon on 27 February the cavalry, supported by tactical air and cavalry helicopter gunships, reported destroying fifteen tanks twelve PT76's and three T54's-and losing three armored cavalry assault vehicles. Later, on 1 March, still southeast of Landing Zone 31, the cavalry was attacked again. In this battle, which lasted throughout the night, the cavalry was supported by South Vietnamese artillery, U.S. tactical air strikes, and cavalry gunships. Fifteen enemy tanks were destroyed; the cavalry lost six armored cavalry assault vehicles.

Despite recommendations from the American adviser of the 1st Armor Brigade and the acting adviser of the division, the commander of the airborne division failed either to support the 17th Armored Cavalry or to withdraw it. On 3 March, after the cavalry was surrounded on three sides by enemy armor and its route of withdrawal was blocked by direct tank gunfire, the South Vietnamese Chief of Armor, with the approval of the I Corps commander, intervened by radio. He obtained air support from I Corps and ordered the 17th Cavalry south to more defensible ground. From there, the cavalry subsequently fought a delaying action and rejoined the 1st Brigade at Aloui.

Air Cavalry and Tanks

Fortunately for Operation LAM SON 719, the confusion on the ground did not extend to the air cavalry. The performance of the air cavalry remains one of the outstanding achievements of the operation, particularly since it operated in the most hostile air environment of the war. All air cavalry in Laos was controlled by


the U.S. 2d Squadron, 17th Air Cavalry, which reported directly to the U.S. XXIV Corps. In addition, the cavalry had operational control of the reconnaissance company of the South Vietnamese 1st Infantry Division. Called the Black Panthers, or Hac Bao, the unit was an elite, 300-man company, cross-trained and organized into aerorifle platoons, and used for ground operations in Laos.

The greatest threat to air cavalry was fire from .51-caliber machine guns, which the North Vietnamese Army employed in large numbers, locating them in mutually supporting positions. The OH-6A scout helicopter was too vulnerable to heavy fire from these guns to operate as part of the reconnaissance team. Instead, groups of two to six AH-1G Cobras and one command and control aircraft were formed, with scout pilots as front seat gunners in the Cobras. Although not designed as a scout ship, the Cobra did well in the reconnaissance role. Its weapons could immediately engage the enemy and it was powerful enough to make runs at high speed through hostile areas without taking unacceptable risks.

When the squadron encountered tanks for the first time, high explosive antitank (HEAT) rockets were not available, and it used whatever ordnance was on board. The Cobra gunships opened fire at maximum range, using 2.75-inch flechette rockets to eliminate enemy troops riding on the outside of the tank and to force the crew to close the hatches. As the gun run continued, high-explosive and white phosphorus rockets and 20-mm. cannon fire were used against the tank itself.

Eventually HEAT rockets became available, but they were not always effective. Although these rockets were capable of penetrating armorplate, they could do so only in direct hits. Engagements therefore had to take place at ranges of 900 to 1,200 meters, distances that exposed the gunship to the tank's heavy machine gun and to supporting infantry weapons. Between 8 February and 24 March, air cavalry teams sighted 66 tanks, destroyed 6, and immobilized 8. Most of the tanks, however, were turned over to fixed wing aircraft, which could attack with heavier ordnance.

The Withdrawal

After the 17th Armored Cavalry withdrew from Landing Zone 31 and returned, the 1st Armor Brigade task force continued to occupy bases near Aloui. Again because of conflicting orders from the airborne division and I Corps headquarters, the brigade did not move farther west and therefore became a target for intense enemy fire; losses in men and equipment mounted. Eventually a point was reached when the 1st Armor Brigade could not, if it had been


ordered, move west of Aloui. As a result, the 1st Infantry Division was ordered to seize Tchepone, and did so on 6 March with an airmobile assault into Landing Zone Hope.

By early March enemy forces in the LAM SON 719 area had increased to five divisions: 12 infantry regiments, 2 tank battalions, an artillery regiment, and at least 19 antiaircraft battalions. After encountering enemy armored vehicles at Landing Zone 31, South Vietnamese planners had realized that North Vietnamese armor was present in strength, and the 1st Armor Brigade was strengthened with additional units as they became available. The reinforcement was so piecemeal and the troops came from so many different units, however, that it was difficult to tell just who or what was committed. Many units never reached Aloui and merely became part of the withdrawal problem. Even with all the detachments, attachments, additions, and deletions, only one-third of the cavalry squadrons and two-thirds of the tank squadrons available to I Corps were used in Laos. Numerically, this employment amounted to five tank squadrons and six armored cavalry squadrons.

Faced with superior enemy forces, the I Corps commander decided to withdraw. Although units attempted to evacuate the landing zones in an orderely fashion, constant enemy pressure caused several of the sites to be abandoned and forced the defenders to make their way overland to more secure pickup zones. Several units had considerable difficulty breaking away from the pursuing enemy and were lifted out only after intense tactical air, artillery, and aerial rocket preparation.15 By 21 March the 1st Infantry Division had completely withdrawn from Laos and major elements of the airborne division had been lifted out.

The I Corps commander ordered the 1st Armor Brigade to withdraw on 19 March. He further allocated two U.S. air cavalry troops to the airborne division to cover the move. With the 11th Armored Cavalry Regiment as rear guard the 1st Armor Brigade began its withdrawal on time, but the brigade received no air cavalry support. Both troops had been diverted by the airborne division to support airborne battalions elsewhere.

At a stream crossing halfway between Aloui and Landing Zone Alpha, the armored column was ambushed by a large North Vietnamese force. The unit in front of the 11th Armored Cavalry abandoned four M41 tanks in the middle of the stream, where they


completely blocked the withdrawal route. The airborne infantrymen refused to stay with the cavalry and continued east down the road. The armor brigade commander was informed of the situation but sent no reinforcements or recovery vehicles to clear the crossing. Troopers of the 11th continued to fight alone, and after three hours succeeded in moving two of the abandoned tanks out of the way. The cavalry then crossed, leaving seventeen disabled vehicles to the west of the stream. The North Vietnamese immediately manned the abandoned vehicles, which they used as machine gun positions until tactical air strikes destroyed them on 25 March. What had begun as an orderly withdrawal was rapidly becoming a rout.

The armor brigade reached Landing Zone Alpha on 20 March, regrouped, and pushed on, still without benefit of air cavalry. The next morning the brigade, with the 11th Armored Cavalry leading, was again ambushed, this time three kilometers east of Fire Support Base Bravo. In the midst of the firefight, an air strike accidentally hit the Vietnamese column with napalm, killing twelve and wounding seventy-five. The brigade withdrew west to regroup.

By that time the armor brigade had lost approximately 60 percent of its vehicles, and when a prisoner reported that two North Vietnamese regiments were waiting farther east along Route 9 to destroy it the armored force turned south off the road. The airborne division, also aware of the prisoner's statement, had meanwhile airlifted troops north of Route 9 and cleared the ambush site. The armor brigade, unaware of the airborne action, found a marginal crossing over the Pon River, two kilometers south of Route 9. The brigade recrossed the river twelve kilometers to the east and reached Vietnam through the positions of the 1st Battalion, 77th Armor.

The withdrawal of the 1st Armor Brigade is perhaps the most graphic example of the poor coordination between major commands throughout LAM SON 719. When the brigade left Route 9, less than 5 kilometers from Vietnam via road, it was forced to make two river crossings because its commander was not told that the road had been cleared. It was this lack of coordination at the highest levels, and the apparent lack of concern for the armored forces, that contributed to the poor performance of armor.

In Operation LAM SON 719, which officially ended on 6 April 1971, South Vietnamese armor did not appear to advantage. In a static role at Aloui, armor proved no more dynamic than a pillbox, and became a liability requiring additional forces for its security. Command and control problems at all levels were evident, and


plagued the operation from the start. A small amount of armor was committed at first, and reinforcement was piecemeal. None of this, however, excused the performance of some armored units which, especially during the withdrawal, simply abandoned operational vehicles in their haste to get back to safety.

Some good did come from LAM SON 719. For example, it helped to delay major enemy operations for the remainder of 1971. The intelligence gained concerning the North Vietnamese pipeline and trail network in Laos was used for planning future bombing raids.16 The operation allowed the South Vietnamese forces to use U.S. aviation and artillery support without the assistance of American advisers, and thus paved the way for the South Vietnamese Army's complete operational control of U.S. aviation and artillery in midsummer of 1971.

Before this operation, the South Vietnamese infantry had little or no antitank training, but the presence of enemy armor during LAM SON 719 led to greater emphasis on antiarmor techniques and instruction in the use of the M72 light antitank weapon. Both sides in LAM SON 719 lost heavily in men and equipment and there was no clearcut victory, but psychologically the Vietnamese armored forces had received a hard blow

Notice: All materials herein (the domain and associated websites with as part of their domain name) are covered by one or more portions of US copyright laws. Unauthorized copying or use can be prosecuted under these laws. All rights reserved by The Society of the Fifth Infantry Division, U.S. Army and / or the original author.

Return to: Lam Son 719

Society of the Fifth Division
Fifth Infantry Division
16-Oct-2005 19:07