- Chapter VII:
- Across the Border: Sanctuaries
in Cambodia and Laos
- As early as 1965 the North Vietnamese used areas of Cambodia and Laos near
the borders of South Vietnam as sanctuaries in which to stock supplies and
conduct training without interference. It was in these countries that the
North Vietnamese built the famous Ho Chi Minh Trail as their principal supply
route to the south. As time wore on and the tempo of the war increased, the
word trail became a misnomer, for a primitive network of jungle paths had
grown into a vast system of improved roads and trails, many of which could
be used the year-round. The image of a North Vietnamese soldier-porter trudging
south from Hanoi for six months with two mortar shells destined for South
Vietnam could no longer be conjured up. By late 1968 the North Vietnamese
were moving most of their supplies by truck, pipeline, and river barge.
- This relatively sophisticated transportation system terminated at depots
within and adjacent to South Vietnam. Combat units in South Vietnam received
supplies from these depots by a simpler but highly organized system of distribution
that made use of small boats, pack animals, and porters. In the late 1960's,
as the free world forces extended their operations into the enemy base areas
in South Vietnam, the enemy regular forces expanded the bases and depots across
the borders in Cambodia and Laos. (,See Map 14, inset) . Since for
political reasons these base areas were inviolate, they provided sanctuaries
to which the North Vietnamese and Viet Cong units could retire periodically
from combat in South Vietnam, train and refit, and return to combat. Free
world forces called these sanctuaries base areas, since they provided not
only supply and maintenance facilities but also training and maneuver areas,
classrooms, headquarters, and even housing for families of soldiers.
- The Cambodian government, under pressure from North Vietnam and China, had
for several years conceded these areas to the enemies of South Vietnam. In
March 1970, however, Marshal Lon Nol of Cambodia seized control of the government.
and began a campaign to restrict the Viet Cong and North Vietnamese in their
use of his country. Lon Nol's efforts hinged on a proposal that would allow
them to continue to use some base areas, but under Cambodian control. Since
it would have severely hampered
- movement of Cambodian-based enemy troops and supplies to and from South
Vietnam, the proposal was rejected by the Viet Cong and North Vietnamese,
who moved to occupy major portions of eastern Cambodia.
- The coalition government of Laos had an arrangement with North Vietnamese
sympathizers that did not permit it to object to Viet Cong and North Vietnamese
operations in Laos. Base areas and their supporting transportation networks
in Laos therefore continued to provide critical support for North Vietnamese
forces operating in South Vietnam, and were a thorn in the side to the free
world forces. At one time or another most free world soldiers had seen Viet
Cong and North Vietnamese troops moving with impunity on the other side of
the ill-defined border.
- Early Operations Into Cambodia
- As the Cambodian situation became worse, the Cambodian government sought
military assistance from the United States and South Vietnam. In response
the South Vietnamese Army III Corps headquarters launched TOAN THANG 41, a
three-day operation into the so-called Angel's Wing, an area in Cambodia long
used by the enemy for resting and refitting units. Three South Vietnamese
Army task forces, each containing armored cavalry and Ranger units, began
the operation at 0800 on 14 April 1970. They were supported in South Vietnam
by the U.S. 25th Infantry Division. At midday, eight kilometers inside Cambodia,
a sharp fight broke out, and fierce hand-to-hand combat continued until late
afternoon, when the enemy broke away and fled. The next day the capture of
several base camps revealed the full extent of enemy logistical operations
in Cambodia. Plans called for the Vietnamese Air Force to evacuate captured
supplies, but because of the inexperience of the Vietnamese in large-scale
logistical airlift operations most material had to be evacuated by truck or
tracked vehicle. What could not be removed was destroyed. In all, 378 of the
enemy were killed and 37 captured. Eight South Vietnamese soldiers were killed.
Success brought confidence to the South Vietnamese government and the army.
- Thus encouraged, the South Vietnamese Army decided to expand operations
into the Crow's Nest area on 20 April 1970. The expedition was planned by
the South Vietnamese, and involved three armored cavalry regiments and. three
Ranger battalions under control of the Vietnamese 4th Armored Brigade. The
attack lasted three days, and again was conducted without U.S. advisers or
U.S. support once the troops were across the border. After two days of
- costly defeats, the enemy fled, and the South Vietnamese forces turned to
evacuating large quantities of captured weapons and ammunition. The difficulties
experienced in using armored cavalry assault vehicles to haul captured equipment
prompted field commanders to request that in future operations ammunition
caches be destroyed.
- On 28 April the Vietnamese 2nd and 6th Armored Cavalry Regiments and Vietnamese
Regional Forces attacked again into the Crow's Nest. American advisers were
still not allowed on the ground in Cambodia, but for the first time U.S. support
was used-command and control helicopters and gunships. The attack penetrated
many enemy bases and diverted enemy attention from the larger attacks in III
Corps Tactical Zone.
- These early raids, a prelude to the major effort, helped to improve South
Vietnamese procedures and techniques for use in more open warfare. They also
afforded the free world forces a brief but eye-opening look at the massive
size of the support facilities located across the border. Materiel and intelligence
information confirmed in military minds the absolute necessity for large-scale
operations into all the base areas. As a result of the attacks, the frustration
built up over five years was vented, and success caused confidence and morale
in the South Vietnamese Army to soar. Unfortunately, these operations also
served to warn the Viet Cong and North Vietnamese that more attacks could
be expected, and a hasty exodus of enemy units and headquarters to the west
and north began.
- After the enemy offensives of 1968, the tactics of free world forces underwent
a change; from defensive, counterinsurgency tactics the allies began moving
toward the offensive and toward the employment of more conventional tactics.
The operations to secure the borders and clear the base areas in South Vietnam
heralded this change. In the massive attacks into the border sanctuaries,
which resembled exploitation or pursuit in conventional warfare, the change
in tactics reached full course, and at all levels of command the difference
- The Main Attack Into Cambodia
- The major attack into Cambodia was a series of operations jointly planned
and conducted by South Vietnamese and American units, directed at the highest.
levels, and involving the headquarters and forces of the South Vietnamese
Army in the III and IV Corps zones and the U.S. II Field Force, Vietnam. When
it began, Operation TOAN THANG 42, the Vietnamese portion, was probably the
best planned South Vietnamese operation to that date. Weather
- and terrain were important considerations; it was recognized that any delay
would invite considerable difficulties since the monsoon season would begin
in late May. The weather in late April and early May would be good. The area
chosen for the first attack was flat, with few natural obstacles to cross-country
movement. The operation was planned by III Corps headquarters under conditions
of great secrecy, and the participating Vietnamese units received only sketchy
details until the plan was released on 27 April.1
Early in the planning stage American advisers to South Vietnamese
units acted as coordinators rather than advisers. Once the operation began,
advisers were responsible for requesting and controlling American aid in the
form of medical evacuation, close air support, and artillery fire. The advisers
remained with their Vietnamese units up to thirty kilometers inside Cambodia;
a presidential decree banned all U.S. ground participation beyond the thirty-kilometer
- The operation was planned so that U.S. and South Vietnamese forces were
separated by well-defined boundaries although they attacked simultaneously.
This arrangement considerably simplified coordination and logistical planning
and avoided possible confusion on the ground. The attack resembled a large
double envelopment, with the South Vietnamese forces forming most of the western
pincer and the American forces the center and the eastern pincer. (Map
14) Throughout the attack Vietnamese forces operated in combined arms
task forces with infantry, artillery, and armored cavalry. The one exception
was in the east in the airmobile assault of a South Vietnamese airborne brigade
under U.S. control.
- Operation TOAN THANG 42 began at 0710 on 29 April, less than forty-eight
hours after the participating units were informed, when South Vietnamese task
forces attacked to destroy enemy forces and supplies in Cambodia's Svay Rieng
Province. The mission included opening and securing National Highway 1 to
allow the evacuation of Vietnamese refugees and assisting the hard-pressed
Cambodian Army to regain control of its territory.
- All three task forces moving south and west in the Angel's Wing met the
enemy during the first two days. The Viet Cong and North Vietnamese had anticipated
the attack and fought a stubborn delaying action, hoping to evacuate supplies
and equipment. Nonetheless, the first objectives were quickly achieved, and
on 1 May the
- MAP 14
- South Vietnamese swept west to the provincial capital of Svay Rieng, opening
Route 1 to the east to Vietnam. The speed and success of this attack had in
part been made possible by lessons learned in previous forays. The advance
had been preceded by heavy air and artillery attacks on key areas inside Cambodia.
Unlike the procedure in previous operations, assault units kept on attacking
while follow-up units were responsible for the removal of captured supplies.
- While the enemy's attention was riveted on the Angel's Wing region, the
eastern pincer of the envelopment, TOANG THANG 43, was to attack under the
command of Brigadier General Robert L. Shoemaker, assistant division commander
of the 1st Cavalry Division (Air) . His task force included the 3d Brigade
of that division,
- the 2d Battalion, 34th Armor (-), the 2d Battalion, 47th Infantry (Mechanized),
the South Vietnamese 3d Airborne Brigade, and the U.S. 11th Armored Cavalry.2
- Following intensive air and artillery bombardment, the airborne brigade
was to stage a helicopter assault into the area north of the Fishhook to seal
off escape routes, while ground units attacked north. Air cavalry was to conduct
screening operations as South Vietnamese cavalry screened the east flank in
Vietnam. Task Force Shoemaker's mission was to locate and eliminate enemy
forces and equipment. There was also a possibility that the Central Office
for South Vietnam, the elusive enemy headquarters, would be found in the Fishhook
and could be destroyed.
- At 0600 on 1 May, U.S. artillery fire exploded on the proposed helicopter
landing zones; the 1st Squadron, 9th Cavalry (Air) , began aerial reconnaissance
and was the first unit to find the enemy. Company C, 2d Battalion, 47th Infantry
(Mechanized), closely followed on the west by the 2d Battalion, 34th Armor,
led the attack of the 3d Brigade, 1st Cavalry Division (Airmobile) at 0945.
To the east the 11th Armored Cavalry Regiment was hit at the border by elements
of two enemy battalions. From their command vehicles with the lead tank platoon
of the 2d Squadron, Colonel Donn A. Starry, the regimental commander, and
Lieutenant Colonel Grail L. Brookshire, commanding the 2d Squadron, directed
tactical air and artillery fire that immediately suppressed the enemy fire.
The 11th Cavalry crossed the border at 1000.
- The 2d Battalion, 47th Infantry (Mechanized), and the 2d Battalion, 34th
Armor, proceeded north, unopposed, to secure landing zones to be used later
in the day by the 3d Brigade, 9th Infantry Division 3
The 2d and 3d Squadrons, 11th Cavalry, moved north with little opposition
until late afternoon when Company H entered a clearing six kilometers inside
Cambodia. Overhead, a scout helicopter from the regimental air cavalry troop
discovered a large enemy force well entrenched on the edge of the clearing.
The jungle suddenly erupted with enemy fire, and it quickly became evident
that the enemy was on three sides of the 2d Squadron.
- Colonel Starry immediately directed Lieutenant Colonel Bobby
- F. Griffin, 3d Squadron commander, to attack the flank of the enemy defenses.
The air cavalry hit the enemy's rear and his withdrawal routes, and at 1645
the enemy force, estimated at a battalion, broke and fled, leaving fifty-two
dead. Two troopers of the 11th Cavalry were killed, the only American soldiers
to die in Cambodia on 1 May.
- By afternoon on 2 May free world forces were fighting in both wings of the
envelopment. The South Vietnamese forces in the Parrot's Beak attacked south
with two task forces from the III Corps Tactical Zone, while three task forces
from IV Corps attacked north.4
The object was to trap the enemy with elements of nine cavalry regiments.
The 7th Squadron, 1st Cavalry (Air), sweeping ahead and to the flanks, had
one troop credited with killing over 170 Viet Cong and North Vietnamese. The
rapidly moving cavalry squadrons and U.S. air cover quickly broke the resistance
of enemy troops and chased them into the guns of the other South Vietnamese
task forces. The two South Vietnamese forces linked up early on the afternoon
of 4 May. Over 400 of the enemy were killed; 1,146 individual weapons, 174
crew-served weapons, more than 140 tons of ammunition, and 45 tons of rice
- In the eastern wing on 2 May, the 2d Battalion, 47th Infantry (Mechanized),
cut Route 7 near Memot (Memut) ; the 2d Squadron, 11th Armored Cavalry, linked
up with the South Vietnamese airborne forces. A search for supply caches met
little resistance from enemy security forces.
- Late on 3 May the 11th Cavalry was ordered to attack north forty kilometers
to take the town of Snuol and its important road junction. Route 7, leading
north to Snuol through large rubber plantations, was chosen as the axis of
advance, and by early afternoon on the 4th, the lead tanks had broken out
of the jungle and were on the ridge astride the highway. Once on the road
the 2d Squadron, followed by the 3d, raced north at speeds up to sixty-five
kilometers per hour and reached the first of three destroyed bridges by midafteroon.
The cavalry secured the site, placed I an armored vehicle launched bridge
across the stream, and went on.5
- With his regiment now strung out for almost sixty kilometers, Colonel Starry
decided to consolidate south of the second stream
- THE 2D SQUADRON, 11TH ARMORED CAVALRY, ENTERS SNUOL, CAMBODIA
- crossing. Through the night, the 2d and 3d Squadrons closed on the lead
elements, which were now reconnoitering the two remaining crossings. The 11th
Armored Cavalry Regiment continued north on 5 May after Company H and Troop
G laid another vehicle launched bridge at the second crossing site. The third
crossing posed serious problems because it would require heavy bridging. A
flying crane, the CH-54 helicopter, was requested to transport an M4T6 bridge
to the site, but by midday when the 2d Squadron reached the third crossing
site the crane pilots and the engineers had made little progress. Anxious
not to lose the momentum of the attack, Colonel Starry set out on foot with
the section sergeant and the bridge launching vehicle to find a place where
the span could be used. After gingerly testing several places, they let down
the bridge, tried it out with Troop G, and by 1300 the 2d and 3d Squadrons
were again rolling north.
- The 2d Squadron paused south of Snuol to bring up artillery, organize air
support, and reconnoiter. Refugees reported that there were many North Vietnamese
troops in the town and that the civilians had fled. Scouts from the regimental
air cavalry troop had observed heavy antiaircraft fire all around the airstrip
to the east of town. In midafternoon the 11th Cavalry surrounded the city,
with the 2d Squadron on the east and the 3d Squadron on the west. As tanks
and armored cavalry vehicles rumbled across the Snuol airstrip, they were
hit by rocket propelled grenades and small arms
- fire, which ceased abruptly when the tanks replied with cannister. After
a brisk fight, the antiaircraft guns were seized.
- The 3d Squadron, meanwhile, moving through the rubber trees to encircle
the town, triggered an ambush set to hit the 2d Squadron. Colonel Griffin
placed artillery fire behind the enemy position, set up gunships to cover
the right flank, and attacked with Troop I. As the 2d Squadron moved in from
the southeast in a coordinated attack, an inexperienced gunship pilot fired
rockets into the lead elements. This unfortunate incident caused the gunships
to be withdrawn and opened one side of the trap as an escape route for the
enemy. The two-squadron attack, however, routed the enemy troops, who fled
in small groups in all directions. When the cavalry entered Snuol, the city
- Snuol was apparently the hub of an extensive logistical operation. On the
following day, 6 May, the 2d Squadron discovered an improved road, large enough
for trucks and carefully hidden under the jungle canopy. Along the road the
cavalry found and destroyed an abandoned truck convoy laden with supplies.
The cavalrymen also discovered in Snuol a fully equipped motor park, complete
with grease racks and spare parts, and a large storage site containing 85-mm.
tank glen ammunition.
- While American units were attacking toward Snuol, South Vietnamese armored
task forces in the southwest were expanding their area of operation to the
north. Finding only disorganized enemy groups, the well-coordinated Vietnamese
units quickly reached the Kampong Spean River and secured Kampong Trach. To
the west of the town, an armor-heavy force overcame stiff resistance from
three North Vietnamese battalions. The attacking armored units were closely
followed by dismounted Rangers who eliminated the bypassed pockets of the
enemy. This coordinated combined arms attack, supported by tactical air and
artillery, demonstrated that the problems encountered during earlier South
Vietnamese operations had been solved.
- On 7 May President Nixon announced his satisfaction with the progress of
the operations, and stated that U.S. troops would be withdrawn from Cambodia
by 30 June. This announcement brought intensified search efforts, prompting
additional attacks into Cambodia in the Dog's Head area and toward Krek by
units of the 25th Infantry Division. The 1st Brigade moved on 14 May to come
abreast of the 2d Brigade, which had been committed earlier in the Fishhook
area. The move was led by the 2d Battalion, 22d Infantry (Mechanized) , the
1st Battalion, 5th Infantry (Mechanized) , and elements of the 3d Squadron,
4th Cavalry. These troops were to act as a blocking force north of the Kampong
- for the South Vietnamese task forces that were now moving from Svay Rieng
west to Kampong Trabek. Advancing in two columns on Route 1, and bypassing
several small forces, a South Vietnamese task force covered over thirty kilometers
to Kampong Trabek in slightly over two hours and linked up with South Vietnamese
forces from IV Corps who were moving north toward Phnom Penh.
- As the 18th Armored Cavalry Regiment was moving toward the linkup, the 15th
Armored Cavalry Regiment collided with the 88th North Vietnamese Regiment,
which was about to attack the 18th Armored Cavalry from the rear. Surprised,
the enemy regiment tried to withdraw, but the fast-moving South Vietnamese
force literally ran over it. A day-long, running battle left North Vietnamese
Army resistance shattered, the enemy in flight, and the field covered with
enemy casualties and abandoned weapons.
- While the U.S. 25th Infantry Division held the center of the potential envelopment,
a South Vietnamese task force moved north on 17 May to secure Route 15, halfway
to the besieged town of Kampong Cham. Other South Vietnamese task forces spread
out to secure the penetration, and Vietnamese district and province forces
moved in to perform the detailed search and evacuation of captured material.
On 9 May the 1st Squadron, 11th Armored Cavalry Regiment, which had been securing
the line of communications to Tonle Cham in War Zone C, moved into Cambodia
to search the rubber plantations at Memot. The cavalrymen discovered a motor
park with twenty-one American-made 21/2-ton trucks of World War II vintage
that had been used in Korea (data plates were still on the vehicles) , rebuilt
in Japan, and sold as surplus. Once the batteries were replaced, the 1st Squadron
had its own truck convoy to haul captured equipment and supplies back into
- As operations in and around the Fishhook continued it became evident that
the free world forces had seriously underestimated the extent of enemy logistical
bases in Cambodia. Consequently, the 11th Armored Cavalry Regiment was assigned
two engineer land clearing companies and along with the Vietnamese airborne
brigade began extensive Rome plow operations in the Fishhook. By late May
the southern Fishhook, which had become the most hotly contested portion of
TORN THANG 43, contained two squadrons of the 11th Armored Cavalry Regiment.
The monsoon had arrived, and movement became more difficult every day. As
June wore on the enemy became more persistent, and small daily fights were
a fact of life. Helicopters flying over the area habitually received ground
fire. Road-mining incidents and ambushes increased. None-
- theless, the Rome plows cleared over 1,700 acres of jungle and destroyed
more than 1,100 enemy structures.
- In accordance with the presidential directive, plans were made to withdraw
U.S. forces from Cambodia by 30 June. The 2d Squadron, 11th Armored Cavalry,
moved along Highway 13 to Loc Ninh, while in the Fishhook the 1st and 3d Squadrons
departed through Katum. The 3d Squadron was ordered to remove the bridge sections
south of Snuol and to destroy the fire bases established along Route 7 near
Memot, a job made more difficult as the monsoon inundated the low ground,
leaving track vehicles virtually roadbound. With considerable difficulty the
bridges were removed or destroyed by the 3d Squadron as it withdrew. Captain
Ralph A. Mile's Troop L was the last U.S. armored unit to leave Cambodia.
- South Vietnamese Army Attacks Continue
- In late May, with the impending American withdrawal from Cambodia still
to come and the monsoon rains increasing, the South Vietnamese forces, unhindered
by the U.S. political decision, had continued attacking to complete the encirclement.
The Chup rubber plantation near Kainpong Cham was selected as the linkup point
for the converging task forces. The city, a key provincial capital strategically
located on the Mekong River, fifty kilometers northeast of Phnom Penh, was
besieged by the 9th North Vietnamese Division, which had its headquarters
in the plantation. The South Vietnamese objective was to attack the plantation
from the south and east, thus eliminating enemy pressure on Kampong Chain
and completely encircle the base areas.
- At 0730 on 23 May, a South Vietnamese armored task force passed through
the U.S. forces near Krek and ran head on into an entrenched rifle company
from the 272d Viet Cong and North Vietnamese Regiment, intent on stopping
any advance along Route 7. The enemy opened with rocket propelled grenade
and small arms fire on the lead tanks of the 5th Armored Cavalry Regiment,
which quickly formed on line and attacked. A short, fierce, close quarters
fight left most of the enemy dead or captured. The action was so fast that
units in the rear of the advancing column were unaware of the battle until
they passed the enemy dead along the road. Another South Vietnamese armored
task force moving north along Highway 15 on 25 May encountered an enemy battalion
at the Chup plantation. The 15th and 18th Armored Cavalry Regiments hit the
enemy positions from two sides, completely disorganizing the resistance. Fire
from the advancing tanks and armored cavalry assault vehicles left over 110
North Vietnamese dead. Three days
- later in the southwestern part of the Chup plantation, another enemy battalion
was defeated in a six-hour action. The task forces joined on 29 May, breaking
the seige of Kampong Cham and surrounding the enemy base areas to the south.
- In mid-June, when the 9th North Vietnamese Division Teentered the Chup plantation,
again threatening Kampong Cham and Prey Veng, South Vietnamese units began
a new drive to clear the plantation and destroy the enemy division. For six
days an armor-heavy task force chased the enemy through the rubber plantation
and south along Route 15. Finally, the task force was attacked by the 271st
Viet Cong and North Vietnamese Regiment, which planned to cut the Toad and
isolate the task force. The next three days saw some of the heaviest fighting
of TOAN THANG 42. The enemy was well positioned,
but repeated attacks by the 15th and 18th Armored Cavalry Regiments prevented
his control of the road. Attacks by tanks and armored cavalry assault vehicles
with attached infantry and Rangers finally routed the North Vietnamese, and
by 29 June the fighting had ended. The final phase of the operation, 1-22
July, involved road security missions and search operations. No significant
fighting occurred, and all Military Region 3 units had left Cambodia by 22
- The South Vietnamese forces of Military Region 3 periodically returned to
Cambodia during the next eighteen months. Most of their operations were hit
and run, and had limited objectives and minor successes. One operation, TOAN
THANG 01-71, started with high hopes on 4 February 1971 and ended in disaster
four months later. Little was officially reported about this operation since
world attention was dramatically focused on LAM SON 719 to the north
in Laos, and no U.S. ground forces or advisers could be used in Cambodia.
Near the end of May a South Vietnamese task force was cut off in Cambodia
south of Snuol on Route 13. Although the commander had received intelligence
reports from South Vietnamese and U.S. sources, including visual aerial reconnaissance
from the 3d Squadron, 17th Cavalry (Air) , he failed to guard against a growing
- The 3d Armored Brigade was ordered north to link up with the isolated task
force on Route 13. After a misunderstanding of orders, during which the task
force at first refused to attempt to withdraw,
- the task force troops attacked south toward the armored brigade, but intense
rocket, small arms, and machine gun fire quickly disorganized the attack.
Many infantrymen ran from exploding or disabled vehicles; others, trying to
hide from the deadly fire, climbed under or onto the vehicles. Some soldiers
already on the vehicles crawled inside for cover, while more and more attempted
to mount the moving vehicles to escape. As the column continued down the road
it became a rout.
- After two days of massive artillery, air cavalry, and tactical air strikes,
the armor brigade finally accomplished the linkup. The task force passed through
the brigade with each tracked vehicle carrying thirty to thirty-five infantrymen.
Both sides suffered heavily, but for the South Vietnamese forces command and
control again emerged as a serious problem. What had begun as an orderly withdrawal,
turned into a rout. The collapse of command under stress was to plague the
South Vietnamese forces to the end of the war.
- Secondary Attacks Across the Border
- In examining the final results of the expeditions into Cambodia, it is well
to note that two separate series of South Vietnamese operations supported
the TOAN THANG attacks. The first, Operation Cuu LONG I-III, from IV Corps
Tactical Zone, lasted from 9 May till 30 June 1970, and involved five armored
cavalry regiments as well as infantry, Rangers, elements of the Vietnamese
Navy, and units of the Regional Forces and Popular Forces. The operational
area was more than ninety kilometers wide and extended north to Phnom Penh.
The object was to secure the Mekong River as far north as the Cambodian capital
so that the Vietnamese refugees gathered in the city could be evacuated to
South Vietnam. The operation indirectly supported III Corps Tactical Zone
forces involved in Operation TOAN THANG 42.
- CUU LONG I began with an assault on locations along the Mekong by aircraft
of the U.S. 164th Aviation Group which formed the largest air armada ever
assembled in IV Corps Tactical Zone for a single operation. By 13 May linkup
had been accomplished with III Corps forces, and the Mekong River was secure
from the border to the capital of' Cambodia. Five hundred of the enemy were
killed. Forty ships passed safely up the Mekong to Phnom Penh, where they
evacuated over 12,000 Vietnamese civilians. Eventually, more than 40,000 Vietnamese
were evacuated through this safe corridor.
- Operations Cuu LONG Il and III, from 17 May to 30 June, were directed at
enemy forces and base camps in southeastern Cambodia. They were designed to
assist the Cambodians in constructing bases
- and reestablishing local government. In both operations cavalry units traveled
rapidly for more than fifty kilometers to relieve besieged Cambodian garrisons,
and then turned their attention to searching for supplies. One cache discovered
by Troop D, 3d Squadron, 5th Cavalry, yielded millions in National Liberation
Front money printed for use in South Vietnam after Tet 1968.
- The other series of operations into Cambodia originated in II Corps Tactical
Zone and was designed to support TOAN THANG 42 by drawing enemy units north
and cutting the enemy logistical lifeline north of the main battle. Operations
BINH TAY I-IV were conducted from Kontum in the north to Ban Me Thuot in the
south and were controlled and executed by the South Vietnamese Army.
- The first three phases of BINH TAY were directed against Base Areas 701,
702, and 740, long utilized to support Viet Cong and North Vietnamese units
operating in the central highlands of the II Corps area. There was little
activity by armored units during these operations; South Vietnamese commanders
preferred to use their armor for security and transportation. Enemy resistance
was light and poorly organized. These first phases, although successful, showed
clearly that the South Vietnamese commanders in II Corps Tactical Zone did
not fully appreciate the possibilities for maneuver and firepower that armored
units possessed. The II Corps cavalry regiments were not given the freedom
of action afforded similar units in the III and IV Corps areas.
- BINH TAY IV, conducted from 24 to 26 June, was the final II Corps operation
in Cambodia. It included the largest aggregation of armored forces in the
II Corps zone and, unlike other BINH TAY operations, was not directed toward
destruction of enemy forces or bases but toward the evacuation of Cambodian
and Vietnamese refugees. The armor spearhead, catching the enemy units off
guard, moved swiftly into Cambodia on 24 June and set up defensive positions
along the withdrawal routes. When the operation ended on 26 June 1970, over
8,500 Cambodians, more than 3,800 of them military, and over 200 vehicles
and much equipment had been removed from the danger of control by the Viet
Cong and North Vietnamese.
- Cambodia in Perspective
- By the end of June free world forces in Cambodia had captured or destroyed
almost ten thousand tons of materiel and food. In terms of enemy needs this
amount was enough rice to feed more than 25,000 troops a full ration for an
entire year; individual weapons to equip 55 full-strength battalions; crew-served
weapons to equip 33 full battalions; and mortar, rocket, and recoilless rifle
- ammunition for more than 9,000 average attacks against free world units.
In all, 11,362 enemy soldiers were killed and over 2,000 captured.
- These statistics are impressive, and without a doubt the Cambodian expeditions
had crippled Viet Cong and North Vietnamese operations, but the most important
results cannot be measured in tangibles alone. The armored-led attacks into
Cambodia by units from Military Region 4 had been well planned, well coordinated,
and well carried out. They were generally conducted without the massive U.S.
ground support typical of operations by units from Military Region 3, yet
they severely hurt the enemy. The South Vietnamese, their morale high, returned
to resume pacification of the delta, a goal which had suddenly come much closer
- In Military Region 3 the results of operations TOAN THANG 42 and 43 were
alo impressive, and had a great pyschological and material effect on the enemy.
Even more important, South Vietnamese forces had operated over great distances
for long periods without direct American assistance and often without advisers.
This fact provided a great boost to South Vietnamese morale and improved fighting
ability. The Vietnamese forces had temporarily strengthened the position of
the Cambodian government and brought some measure of order to its border provinces.
- On the other side of the ledger, the results of the last expedition from
Military Region 3 revealed the continued existence of command and control
problems among South Vietnamese commanders. To overcome timidity and lack
of coordination at high command levels, would, in the final analysis, be more
important than material gains.
- The lack of understanding of armored operations exhibited in Military Region
2 did not bode well for the future, although eventually new commanders there
would begin the process of correction. The boost given to the Cambodian government
and its army was only temporary, for the Viet Cong and North Vietnamese forces
returned and quickly took complete control of all the border areas.
- The most important effect of the operations in Cambodia must be looked for
within South Vietnam; here the attacks bought time for strengthening the Vietnamese
forces and for the United States to continue its withdrawals.8
For the next fourteen months there
- were almost no Viet Cong and North Vietnamese operations in South Vietnam.
The Cambodian operations greatly increased the confidence of Vietnamese armored
forces in their ability to wage a successful and prolonged campaign. It was
the most convincing evidence since Tet 1968 of the improvement
of Vietnamese armored forces. The high morale of the South Vietnamese forces
convinced American advisers that the Vietnamese were well on their way to
being able to fight the war on their own.
- Maintenance and Supply
- One unusual feature of American operations in Cambodia was the American
policy that all vehicles and equipment, no matter how badly damaged-even if
beyond repair-had to be evacuated to Vietnam. While this ruling was made at
high levels for political, intelligence, and propaganda purposes, it calls
attention to a major problem that confronted armored units throughout the
- In an armored unit, the soldier is as dependent on his armored vehicle as
the vehicle is on him. In few other combat units in the Army are maintenance
and the supporting supply system so critical. Most armored units found the
U.S. Army supply and maintenance system in Vietnam to be less than satisfactory
at every level. The deficiencies in the system were basic. As the war expanded
and mobility became more and more important the faults in the system became
- Two faults were apparent in the early years, and they eventually exposed
a third. The first was the lack of general support maintenance-heavy repair
facilities in the major areas where armored vehicles were used. This lack
was the result of the decisions of 1965 and 1966 to build up
combat troops at the expense of the logistical base. Although it was an expedient
meant for a short time, the decision was never really altered. Even more unfortunate
was the fact that in many cases the few support units that were available
were centralized in areas far from the combat units. The obvious solution
to this problem, the use of teams authorized to make major repairs at a unit's
location, however popular with units was not popular with logisticians. Thus,
combat units were frequently forced to send damaged vehicles great distances
for repair. In Military Region 3, vehicles were almost always sent back to
the Long Binh-Saigon-Cu Chi area, a distance of ninety or more kilometers
from the border and base areas where the fighting was. The resulting loss
in combat power and the drain on the meager evacuation resources of the combat
units was a severe hardship.
- In an attempt to solve this problem, Colonel Starry had forced
- repair teams forward to squadron and troop level in the 11th Armored Cavalry
Regiment even before the invasion of Cambodia. To help with the critical problem
of evacuating materiel from Cambodia the 11th Cavalry borrowed six M88 tank
recovery vehicles from the depot at Long Binh. Organized into recovery platoons
operating with the 3d Squadron, these vehicles were invaluable to the regiment's
- The second problem, the tendency of logistical units to stick to base camps,
was evident early in the war and continued to the end. Logistical units, particularly
supply and maintenance elements, were unprepared psychologically and in practice
to live in the field close to the units they supported. Although Army doctrine
stressed that this support should be provided in forward areas, the practice
was to centralize support facilities in built-up, well-developed, permanent
base camps, similar to installations in the United States. In Military Regions
2 and 3, this practice placed support facilities as close to the coast as
possible, often more than 100 kilometers from the fighting units, and accessible
only by means of tenuous supply and evacuation routes. While this placement
was easier for the supply and maintenance units, it was a hardship for the
- The most critical problem was the unsatisfactory performance of the area
support system under combat conditions. It is amazing that the system was
expected to work in a war of movement, in which armored units traveled great
distances in short periods of time. In Vietnam, it was not the answer for
armored units, particularly armored cavalry regiments. According to Lieutenant
General Joseph A. M. Heiser, Jr., former commander of the 1st Logistical Command,
Vietnam, the 11th Armored Cavalry Regiment "obtained its maintenance
support from the 1st Logistical Command on an area basis. As elements of the
regiment relocated, the nearest 1st Logical Command unit provided service.
This method of support proved unsatisfactory because of the 11th ACR's high
and fluctuating maintenance demands. In the future such organizations should
be assigned an organic maintenance unit."
- While the problem was apparent in the 11th Armored Cavalry, it existed also
for the 1st Brigade, 5th Infantry Division (Mechanized) , in northern Military
Region 1. Although the mechanized brigade operated under control of the 3d
U.S. Marine Division, the marines were responsible for supplying only rations
and fuel. The 1st Brigade had its own organic supply and maintenance support
but relied for wholesale level supply on distant Army support units. Several
unanticipated maintenance difficulties developed as
- a result of this extended logistical link. Operations in the sandy soil
of the northern coastal areas caused such excessive track and sprocket wear
that spare parts were frequently inadequate. To cope with the problem, special
brigade convoys were sent directly to the depots in an effort to shorten the
delivery time of parts. Nicknamed the Red Ball Express, these convoys eventually
eased many of the brigade maintenance problems.
- These were not isolated examples, for combined arms operations stressed
cross-attachment at battalion level, with the units often operating over great
distances for long periods of time. The 2d Battalion, 34th Armor, in Military
Region 3 had two companies detached for almost its entire time in the war-four
years. Maintenance support of these two companies remained the responsibility
of the battalion. Since one company was in northern Military Region 1, the
situation became ludicrous when the battalion executive officer had to search
the Saigon area for parts and then airlift them to the Hue area, 750 kilometers
north. The other company, in Military Region 3, was often split among three
locations, yet the battalion had to find and support them daily, even though
the company was attached to a different division. Since the battalion had
a limited resupply and maintenance system, this situation was completely unsatisfactory.
- In Military Region 2, elements of the 1st Battalion, 69th Armor, and 1st
Battalion, 50th Infantry (Mechanized) were often attached to the 1st Air Cavalry
Division, yet the division had no means of repairing armored vehicles. With
the distant parent battalion still responsible for maintenance and logistical
support, the tank and mechanized companies frequently found themselves sorely
pressed for supplies and replacement parts. The 1st Cavalry Division was able
to repair equipment common to both the companies and the division; however,
if the equipment was not common, long resupply delays were normal. In an attempt
to partially solve the problem, Company A, 1st Battalion, 69th Armor, used
its organic vehicles to obtain repair parts directly from the Qui Nhon support
- Examples of the failure of the rigidly structured area support system to
sustain adequately a constantly changing troop concentration are almost endless.
Support units requisitioned parts over a 9,600-mile supply line, with attendant
delays. There were never enough spare parts on hand to repair the armored
vehicles in any given area. When parts were ordered they often arrived after
the units had moved to a different support area, and the requisitioning process
had started again.
- Many demands that could have been met by depots in Vietnam were not met
because the centralized inventory system broke down. Depots had spare parts,
some of them important items, of which they were not even aware. Thus was
born the system of searching for parts that the combat units called scrounging.
The scrounger, or expediter, was an individual or a team from the combat unit
sent to the major spare parts depot, usually in the Saigon area, to walk through
the storage areas in an attempt to locate spare parts. When an item was found,
it had to be formally released by supply control officials, often over the
protests of supply personnel who were positive they did not have the item-even
when it was physically pointed out. This fact was recognized by the Department
of the Army late in the conflict when projects such as Stop/See, Count, Condition,
and Clean were started in an attempt to verify inventories. One inventory
team was sent to Okinawa to open twenty-six acres of shipping containers for
which no inventory existed.
- In combat units, inexperienced crew members, supervisors (officers
and noncommissioned officers), and maintenance personnel contributed to the
problem. Parts were often requested and replaced unnecessarily. Such instances
became more apparent late in the war as a greater number of untrained people
were assigned to unit maintenance operations.9
Compounding this problem was the sometimes improper management of the
battalion parts system that led to inadequate records and failure to order
parts. In 1969 and 1970 the 11th Armored Cavalry was able to reduce its prescribed
load lists by about 75 percent, with a dramatic increase in operational readiness.
The supply system at the unit level was glutted with too much unneeded gear.
Nonetheless, Colonel Starry noted that his regiment was obliged to live off
its battle losses by cannibalizing disabled vehicles; the supply system provided
only half the regiment's needs, cannibalization the rest.
- The critical problem continued to be with the area support system. Although
commented upon in the 1967 report evaluating mechanized and armor combat operations
in Vietnam, a maintenance support unit dedicated primarily to the 11th Armored
Cavalry Regiment was not created until 1970, and then only after the regimental
commander had convinced officers at higher levels that such a measure was
- Evacuation of damaged vehicles was another problem that
M88 HEAVY RECOVERY VEHICLE LOADS DAMAGED APC, JANUARY
1971. This versatile vehicle was the workhorse of the armor recovery
- plagued combat units. Before the Vietnam War the standard practice had been
to leave damaged vehicles at collecting points on the main supply route for
supporting units to dispose of. But in Vietnam no provision for such evacuation
was made, and the responsibility therefore fell entirely upon the combat units.
In Cambodia, for example, combat units evacuated all vehicles to Vietnam no
matter how badly damaged. The 11th Armored Cavalry Regiment eventually devoted
more than one-third of its combat strength in Cambodia to this task.
- Recovery of damaged machines at the small unit level required considerable
ingenuity. Often the vehicles designed for recovery were inadequate, as in
the case of the M578, or were in short supply, like the M88. No unit ever
had these items in the numbers required, and there were never enough spare
parts to repair them on the spot. Because recovery vehicles were frequently
out of action for extended periods, awaiting parts, heavy reliance had to
be placed on the inventiveness of the small unit leader. In many cases the
performance of these leaders was brillant. Such recovery devices as the push-bar,
log extraction, "daisy chain," and block and tackle were field expedients.
- Many of the maintenance problems cited, particularly the attitude of the
support units, exist today and would create the same
- difficulties in a war fought in Europe as they did in Vietnam. In view of
the renewed emphasis on mobile warfare and the heavy odds that armored forces
must face, a much more responsive supply and maintenance system is a necessity.
Forward location of maintenance units, forward support, mobile repair teams,
and quick resupply from accurate inventories must become as routine for combat
service support units as the use of combined arms for armored units.
- 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
- 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)
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
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
- 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
- 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-
- ACAV's OF SOUTH VIETNAMESE 1ST ARMORED BRIGADE ON ROUTE 9 IN LAOS, 1971
- 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
- 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
- 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
- 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
- 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
- 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
- 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
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,
- 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,
- 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.
- Cuu Long 44-02
- One other South Vietnamese armored operation in 1971 was significant, although
it was not widely publicized. For one reason, since it occurred at almost
the same time as LAM SON 719, it was lost in the glare of reporting that operation.
For another, penetration into Cambodia, the deepest of the war, made it politically
sensitive. The operation was staged because the North Vietnamese had cut Route
4, the only supply road in Cambodia between Phnom Penh, the capital, and the
port of Kampong Som; the Cambodian government had requested South Vietnamese
assistance in reopening it.
- Operation Cuu Lorry 44-02 began on 13 January 1971, as the 4th Armor Brigade
with the 12th and 16th Armored Cavalry Regiments, three Ranger battalions,
an artillery battalion, and an engineer group, moved 300 kilometers from Can
Tho to Ha Tien in fourteen hours. For the next two days, the brigade pushed
north along Routes 3 and 4. The first enemy encountered had set up an
- ambush that the 16th Armored Cavalry Regiment literally blew away by charging
- A second ambush farther north against the 12th Armored Cavalry also failed.
The enemy tried to isolate the lead squadron by destroying the first and last
vehicles. The lead commander, however, kept his flaming vehicle moving and
his machine gun firing. Hit three times and burning, the armored cavalry vehicle
continued north for about 150 meters before it blew up, killing the crew.
This heroic effort prevented the column from being trapped on the road and
allowed the cavalry to get out of the enemy firing lanes. The Ranger battalion
behind the cavalry squadron stopped and opened fire. The ambushers were now
in a deadly cross-fire between the cavalry and the Rangers. Two U.S. aerial
fire teams sealed off the enemy escape routes.17
When the smoke cleared, 200 of the enemy lay dead, and seventy-five weapons,
including two 75-mm. recoilless rifles and three heavy machine guns, had been
captured. The 12th Armored Cavalry Regiment lost five killed, twenty wounded,
and three tracks destroyed.
- On 17 January Cambodian forces, with Vietnamese Marine Corps support, fought
to the outskirts of the Pich Nil Pass and secured it, while the armor brigade
secured Route 4 as far north as Route 18. After helping the Cambodians set
up strongpoints, the 4th Armor Brigade withdrew toward South Vietnam, arriving
by 25 January.
- On several occasions, Vietnamese armored units had conducted bold operations
deep into enemy territory, in both Laos and Cambodia. Three major operations,
Cuu LONG 44-02, LAM SON 719, and TORN THANG 01-71, all took place simultaneously,
with the South Vietnamese hoping to keep the initiative gained in 1970. Of
the three operations, only Cuu LONG 44-02 can be regarded as a success, and
as a result Military Region 4 remained one of the most secure areas in South
Vietnam. The other two operations demonstrated that a parity existed in South
Vietnamese-North Vietnamese strength. The year 1971 was not successful for
either side; it ended with the Viet Cong and North Vietnamese as strong, if
not stronger, than the South Vietnamese.
- page created 17 January 2002
Return to the
Table of Contents