The Hồ Chí Minh trail (also known in Vietnam as the "Trường Sơn
trail") was a logistical system that ran from the Democratic Republic
of Vietnam (North Vietnam) to the
Republic of Vietnam
Republic of Vietnam (South Vietnam)
through the kingdoms of Laos and Cambodia. The system provided
support, in the form of manpower and materiel, to the National Front
for the Liberation of South Vietnam (called the
Viet Cong or "VC" by
its opponents) and the
People's Army of Vietnam
People's Army of Vietnam (PAVN), or North
Vietnamese Army, during the Vietnam War.
It was named by the Americans after North Vietnamese president Hồ
Chí Minh. Although the trail was mostly in Laos, the communists
called it the Trường Sơn Strategic Supply Route (Đường
Trường Sơn), after the Vietnamese name for the Annamite Range
mountains in central Vietnam. According to the United States
National Security Agency's official history of the war, the Trail
system was "one of the great achievements of military engineering of
the 20th century".
1 Origins (1959–1965)
1.1 Base areas
Interdiction and expansion (1965–1968)
2.1 Air operations against the trail
2.2 Ground operations against the trail
Operation Commando Hunt
Operation Commando Hunt (1968–1970)
3.1 Fuel pipeline
3.2 Truck relay system
4 Road to
PAVN victory (1971–75)
5 See also
Further information on
Viet Minh operations in Laos: First Indochina
Parts of what became the trail had existed for centuries as primitive
footpaths that facilitated trade. The area through which the system
meandered was among the most challenging in Southeast Asia: a
sparsely-populated region of rugged mountains (500–2,400 metres
(1,500–8,000 ft)), triple-canopy jungle and dense primeval
rainforests. During the
First Indochina War
First Indochina War the Việt Minh maintained
north/south communication using this system of trails and paths.
In the early days of the
Ho Chi Minh
Ho Chi Minh trail, bicycles were often used
to transport arms and equipment from North Vietnam to South Vietnam.
Hanoi established the 559th Transportation Group under the
command of Colonel (later General) Võ Bẩm to improve and maintain a
transportation system to supply the NLF uprising against the South
Vietnamese government. Originally, the North Vietnamese effort
concentrated on infiltration across and immediately below the
Demilitarized Zone that separated the two Vietnams.
As early as May 1958
Pathet Lao forces had seized the
transportation hub at Tchepone, on Laotian Route 9. This had been
accomplished due to the results of elections in May that had brought a
right-wing government to power in Laos, its increasing dependence on
U.S. military and economic aid, and an increasingly antagonistic
attitude toward North Vietnam. The 559th Group "flipped" its line
of communications to the western side of the Trường Sơn
By 1959, the 559th had 6,000 personnel in two regiments alone, the
70th and 71st, not including combat troops in security roles or
North Vietnamese and Laotian civilian laborers. In the early days of
the conflict the trail was used strictly for the infiltration of
manpower. This was due to the fact that
Hanoi could supply its
southern allies much more efficiently by sea.
After the initiation of U.S. naval interdiction efforts in coastal
waters, known as Operation Market Time, the trail had to do double
Materiel sent from the north was stored in caches in the border
regions that were soon retitled Base Areas, which, in turn, became
sanctuaries for NLF and
PAVN forces seeking respite and resupply after
conducting operations within South Vietnam.
There were five large Base Areas (BAs) in the panhandle of Laos (see
map). BA 604 was the main logistical center during the Vietnam War.
From there, the coordination and distribution of men and supplies into
South Vietnam's Military Region I and BAs further south was
BA 611 facilitated transport from BA 604 to BA 609 and the supply
convoys moving in either direction. It also fed fuel and ammunition to
BA 607 and on into South Vietnam's A Shau Valley.
BA 612 was used for support of the B-3 Front in the Central Highlands
of South Vietnam.
BA 614, between Savannakhet, Laos and Kham Duc, South Vietnam was used
primarily for transporting men and materiel into MR 2 and to the B-3
BA 609 was important due to a fine road network that made it possible
to transport supplies during the rainy season.
The notion of barefoot hordes pushing heavily loaded bicycles, driving
oxcarts, or acting as human pack animals, moving hundreds of tons of
supplies in this manner was quickly supplanted by trucks (especially
Soviet, Chinese, or Eastern Bloc models), which quickly became the
main method of supply transportation. As early as December 1961, the
3rd Truck Transportation Group of PAVN's General Rear Services
Department had become the first motor transport unit fielded by North
Vietnamese to work the trail and the use of motor transport
Two types of units served under the 559th Group: "Binh Trams" and
commo-liaison units. A "Binh Tram" was the equivalent of a regimental
logistical headquarters and was responsible for securing a particular
section of the network. While separate units were tasked with
security, engineer, and signal functions, a "Binh Tram" provided the
logistical necessities. Usually located one days march from one
another, commo-liaison units were responsible for providing food,
housing, medical care, and guides to the next way-station. By April
1965, command of the 559th Group devolved upon General Phan Trọng
Tuệ, who assumed command of 24,000 men in six truck transportation
battalions, two bicycle transportation battalions, a boat
transportation battalion, eight engineer battalions, and 45
commo-liaison stations. The motto of the 559th became "Build roads to
advance, fight the enemy to travel."
The system developed into an intricate maze of 5.5-metre-wide
(18 ft) dirt roads (paved with gravel and corduroyed in some
areas), foot and bicycle paths, and truck parks. There were numerous
supply bunkers, storage areas, barracks, hospitals, and command and
control facilities, all concealed from aerial observation by an
intricate system of natural and man-made camouflage that was
constantly expanded and replaced. By 1973, trucks could drive the
entire length of the trail without emerging from the canopy except to
ford streams or cross them on crude bridges built beneath the water's
The weather in southeastern Laos came to play a large role both in the
supply effort and in U.S./South Vietnamese efforts to interdict it.
The southwest monsoon (commonly called the rainy season) from mid-May
to mid-September, brought heavy precipitation (70% of 3,800 mm
(150 in) per year). The sky was usually overcast with high
temperatures. The northwest monsoon (the dry season), from mid-October
to mid-March was relatively drier and with lower temperatures. Since
the road network within the trail system was generally dirt, the bulk
of supply transportation (and the military efforts that they
supported) were conducted during the dry season. Eventually, the bulk
of the trail was either asphalted or hard packed, thus allowing large
quantities of supplies to be moved even during the rainy
Interdiction and expansion (1965–1968)
Further information on the
PAVN logistical system in Cambodia:
In 1961 U.S. intelligence analysts estimated that 5,843 enemy
infiltrators (actually 4,000) had moved south on the trail; in 1962,
12,675 (actually 5,300); in 1963, 7,693 (actually 4,700); and in 1964,
12,424. The supply capacity of the trail reached 20 to 30 tonnes
per day in 1964 and it was estimated by the U.S. that 12,000 (actually
9,000) North Vietnamese regulars had reached South Vietnam that
year. By 1965 the U.S. command in
Saigon estimated that communist
supply requirements for their southern forces amounted to 234 tons of
all supplies per day and that 195 tons were moving through Laos.
Defense Intelligence Agency
Defense Intelligence Agency (DIA) analysts concluded that during
the 1965 Laotian dry season the enemy was moving 30 trucks per day (90
tonnes) over the trail, far above the
demonstrating a key problem which arose when discussing the North
Vietnamese supply effort and U.S. attempts to halt it.
United States officials had only estimates of its enemy's
capabilities; intelligence collection agencies often conflicted with
each other. Thanks to improvements to the trail system (including
opening new routes that would connect to the
Sihanouk Trail in
Cambodia), the amount of supplies transported during 1965 almost
equaled the combined total for the previous five years. During the
year interdiction of the system had become one of the top American
priorities, but operations against it were complicated by the limited
forces available at the time and Laos's ostensible neutrality.
The intricacies of Laotian affairs, and U.S. and North Vietnamese
interference in them, led to a mutual policy of each ignoring the
other, at least in the public eye. However, this didn't prevent
the North Vietnamese from violating Laos's neutrality by protecting
and expanding their supply conduit, and by supporting their Pathet Lao
allies in their war against the central government. U.S. intervention
came in the form of building and supporting a CIA-backed clandestine
army in its fight with the Communists and constantly bombing the
trail. They also provided heavy support for the Laotian
Air operations against the trail
Barrel Roll/Steel Tiger/Tiger Hound areas of operations
On 14 December 1964, the U.S. Air Force's "Operation Barrel Roll"
carried out the first systematic bombardment of the Hồ Chí Minh
trail in Laos. On 20 March 1965, after the initiation of Operation
Rolling Thunder against North Vietnam, President Lyndon B. Johnson
gave approval for a corresponding escalation against the trail
system. "Barrel Roll" continued in northeastern Laos while the
southern panhandle was bombed in "Operation Steel Tiger".
By mid-year the number of sorties being flown had grown from 20 to
1,000 per month. In January 1965, the U.S. command in
control over bombing operations in the areas of Laos adjacent to South
Vietnam's five northernmost provinces, claiming that the area was part
of the "extended battlefield". The request was granted by the
Joint Chiefs of Staff. The area fell under the auspices of "Operation
Political complications were not the only factors seriously hampering
aerial operations. The seasonal monsoons that hindered communist
supply operations in Laos also hampered the interdiction effort. These
efforts were complicated by morning fog and overcast, and by the smoke
and haze produced by the slash-and-burn agriculture practiced by the
indigenous population. During 1968 the U.S. Air Force undertook two
experimental operations that it hoped would exacerbate the worst parts
of the above-mentioned weather patterns. "Project Popeye" was an
attempt to indefinitely extend the rainy monsoon weather over
southeastern Laos by cloud seeding. Testing on the project began in
September above the
Kong River watershed that ran through the Steel
Tiger and Tiger Hound areas. Clouds were seeded by air with silver
iodide smoke and then activated by launching a fuse fired from a flare
pistol. 56 tests were conducted by October; 85% were judged to be
successful. President Johnson then gave authorization for the program,
which lasted until July 1972.
Testing on "Project Commando Lava" began on 17 May. Scientists from
Dow Chemical had created a concoction that, when mixed with rainwater,
destabilized the materials that made up soil and created mud. There
was enthusiasm from the military and civilian participants in the
program, who claimed they were there to "make mud, not war." In
some areas it worked, depending on the makeup of the soil. The first
mission was flown from
Udorn Royal Thai Air Base by three C-130A
aircraft from the 41st Tactical Airlift Squadron, Naha Air Base,
On the previous day, the three airmen from the squadron had scouted
the target area south of
Tchepone in a two engine
CIA aircraft piloted
by a civilian employee. The pilot had failed to load enough fuel on
the reconnaissance aircraft and had to refuel at a Laotian base on the
return trip to Udorn. Since United States armed forces personnel were
never officially acknowledged as being in Laos, the United States
Ambassador to Laos became enraged that U.S. personnel had been spotted
in uniform at the remote refueling field in Laos.
The following day, the three aircraft departed from
Udorn filled with
tons of a mixture of nitrilotriacetic acid and sodium
tripolyphosphate stuffed into cloth bags designed to
break apart at impact. The aircraft flew above 5,000 feet
(1,500 m) until near the target area, then let down to tree top
level for the run-in to the target, flying an in-trail formation with
1,000 feet (300 m) between aircraft. Two A-1E Skyraider aircraft
provided air cover to the mission. The target itself was a road cut
sharply into a hillside on a long traverse.
The drop itself went as planned, with good coverage over the road for
about 800 metres (1⁄2 mi). Later on in the day, the forecast
rain activated the "soap" and the initial reports were that the entire
road had washed into the valley. That night at a party at one of the
CIA watering holes, the C-130 crews and the
celebrated the successful mission. Two other missions were flown by
the same aircrews, operating out of
Cam Ranh Air Base
Cam Ranh Air Base in South
Vietnam. The targets on those two missions were at the northern end of
A Shau Valley, in South Vietnam, but were unsuccessful.
The crews had been told that the North Vietnamese would rush hundreds
of personnel to the drop site and remove the "soap" before the
rainfall that was necessary to activate the chemicals. On the last
mission, the third aircraft, commanded by Captain John Butterfield,
was seriously damaged by ground fire. Although he managed to land at
Chu Lai, the aircraft was a total loss due to a warped wing spar. For
his actions on that day, Capt. Butterfield received the Silver Star
medal. It was decided that the experiment didn't justify the risk, and
the mission was officially cancelled.
Ground operations against the trail
NVA troops on the Trail (photo taken by a U.S. SOG recon team).
See also: Operation Left Jab, Operation Honorable Dragon, Operation
Diamond Arrow, Project Copper, Operation Phiboonpol, Operation
Sayasila, Operation Bedrock, Operation Thao La, and Operation Black
On the ground, the
CIA and the
Royal Lao Army
Royal Lao Army had initially been given
the responsibility of stopping, slowing, or, at the very least,
observing the enemy's infiltration effort. In Laos the agency began
Operation Pincushion in 1962 for that reason. The operation
evolved into Operation Hardnose, in which CIA-backed Laotian irregular
reconnaissance team operations took place.
In October 1965, General Westmoreland received authorization to launch
a U.S. military cross-border recon effort. On 18 November 1965, the
first mission was launched "across the fence" and into Laos by the
MACV-SOG. This was the beginning of an ever-expanding
reconnaissance effort by MACV-SOG that would continue until the
operation was disbanded in 1972. Another weapon in the American
arsenal was unleashed upon the trail on 10 December 1965, when the
B-52 Stratofortress bomber strike was conducted in Laos.
A commonly occurring historical perspective concerning the
interdiction effort tends to support the campaigns (regardless of
their failure to halt or slow infiltration) due to the enemy material
and manpower that it tied down in Laos and Cambodia. This viewpoint
pervaded some official U.S. government histories of the conflict. John
Schlight, in his A War Too Long, said of the PAVN's logistical
"This sustained effort, requiring the full-time activities of tens of
thousands of soldiers, who might otherwise have been fighting in South
Vietnam, seems proof positive that the bombing of the Ho Chi Minh
Trail had disrupted the North Vietnamese war effort."
The same historians would not consider the immense logistical effort
fielded by the U.S. to sustain its military in Southeast Asia as a
waste of manpower and resources, even if only one American soldier in
four assigned to South Vietnam served in the combat arms.
Despite anti-infiltration efforts of the U.S. the estimated total of
PAVN infiltrators for 1966 was between 58,000 and 90,000 men,
including five full enemy regiments. A June 1966 DIA estimate
credited the North Vietnamese with 1,000 km (600 mi) of
truckable roads within the corridor, at least 300 km
(200 mi) of which were good enough for year-round use. 1967
saw a change in command of the 559th Group as Senior Colonel (later
General) Đồng Sỹ Nguyên assumed command. In comparison to the
above DIA estimate, by the end of the year the North Vietnamese had
completed 2,959 kilometers of vehicle capable roads, including 275
kilometers of main roads, 576 kilometers of bypasses, and 450 entry
roads and storage areas.
It was learned by U.S. intelligence that the enemy was using the Kong
and Bang Fai rivers to facilitate food, fuel, and munitions shipments
by loading the materiel into half-filled steel drums and then
launching them into the rivers. They were later collected downstream
by systems of nets and booms. Unknown to the Americans the enemy had
also begun to transport and store more than 81,000 tonnes of supplies
"to be utilized in a future offensive". That future offensive was
launched during the lunar new year
Tết holiday of 1968, and to
prepare for it, 200,000
PAVN troops, including seven infantry
regiments and twenty independent battalions made the trip south.
Throughout the war, ground operations by conventional units were
somewhat limited to brief incursions into border sanctuaries. One
notable operation was Dewey Canyon which took place from 22 January to
18 March 1969 in I Corps. During the operation, the 9th Marine
Regiment attempted to interdict NVA activity in the Da Krong River and
A Shau Valleys. Ground units briefly entered the border areas of Laos
during fighting with elements of the 9th NVA Regiment.
OPERATION TOLLROAD In November 1968 elements of the 4th Infantry
Division, including Infantry and Combat Engineers, embarked from the
Plei Trap Valley in Vietnam and proceeded to follow the Ho Chi Minh
Cambodia and North into Laos, where they were extracted by
helicopter on December 1. The mission was accomplished in two
sections, the first in Cambodia, and the second when replacements were
provided as the operation was crossing the Laotian border. The purpose
of the mission was to render the trail unusable by creating abitis,
destroying bunkers and bridges, and cratering the road. The incursion
started on 25 November and ended December 1. The replacement units
arrived on November 29. All personnel were removed by December 1. It
is to be noted that on Thanksgiving evening a traditional Thanksgiving
turkey dinner was delivered by helicopter to the troops in Laos per
order of then-President Lyndon Johnson. The operation began at
coordinates YA 747922 and the final extraction in Laos was at
coordinates YB 726078. 
Operation Commando Hunt
Operation Commando Hunt (1968–1970)
Further information on the interdiction campaign: Operation Commando
Further information on the electronic sensor system: Operation Igloo
Ho Chi Minh
Ho Chi Minh Trail, 1970.
In the wake of the Tet Offensive, the North Vietnamese showed signs of
expanding and modernizing their logistical effort. The number of
supply and maintenance personnel had fallen, mainly due to increased
use of motor/river transportation and mechanized construction
CIA estimated during the year that the 559th Group was
using 20 bulldozers, 11 road graders, three rock crushers, and two
steamrollers for maintenance and new road construction.
As many as 43,000 North Vietnamese or Laotians (most of whom were
pressed into service) were engaged in operating, improving, or
extending the system. In 1969, 433,000 tonnes of ordnance fell on
Laos. This was made possible by the close-out of "Operation
Rolling Thunder" and the commencement of "Operation Commando Hunt" in
November 1968. U.S. aircraft were freed for interdiction missions and
as many as 500 per day were flying over Laos. By the end of 1968,
bombing missions over southern Laos had climbed 300 percent, from
4,700 sorties in October to 12,800 in November.
This round-the-clock aerial effort was directed by "Operation Igloo
White", run out of Nakhon Phanom, Thailand. It was composed of three
parts: strings of air-dropped acoustic and seismic sensors collected
intelligence on the trail; computers at the Intelligence Collection
Center (ICS) in Thailand collated the information and predicted convoy
paths and speeds; and an airborne relay and control aircraft which
received the signals from the sensors and routed aircraft to targets
as directed by the ISC.
This effort was supported by MACV-SOG recon teams, who, besides
carrying out recon, wiretap, and bomb damage assessment missions for
"Commando Hunt", also hand-emplaced sensors for "Igloo White".
Personnel interdiction was abandoned by early 1969. The sensor system
was not sophisticated enough to detect enemy personnel, so the effort
was given up until "Operation Island Tree" in late 1971. A revelation
for U.S. intelligence analysts in late 1968 was the discovery of a
petroleum pipeline running southwest from the northern port of
Early in 1969, the pipeline crossed the Laotian frontier through the
Mu Gia Pass
Mu Gia Pass and, by 1970, it reached the approaches to the A Shau
Valley in South Vietnam. The plastic pipeline, assisted by numerous
small pumping stations, managed to transfer diesel fuel, gasoline, and
kerosene all through the same pipe. Due to the efforts of the PAVN
592nd Pipelaying Regiment, the number of pipelines entering Laos
increased to six that year.
The 559th Group was made the equivalent of a Military Region in 1970
and again placed under the command of General Đồng Sỹ Nguyên.
The unit was reorganized into five divisional headquarters: the 470th,
471st, 472nd, 473rd, and the 571st. The group consisted of four truck
transportation regiments, two petroleum pipeline regiments, three
anti-aircraft artillery (AAA) regiments, eight engineer regiments, and
the 968th Infantry Division. By the end of 1970 the 559th was running
27 "Binh Trams", which transported 40,000 tonnes of supplies with a
3.4% loss rate during the year.
Truck relay system
These supplies traveled in convoys from North Vietnam in relays, with
trucks shuttling from only one way-station to the next. The vehicles
were then unloaded and reloaded onto "fresh" trucks at each station.
If a truck was disabled or destroyed, it was replaced from the assets
of the next northern station and so on until it was replaced by a new
one in North Vietnam. Eventually, the last commo-liaison station in
Cambodia was reached and the vehicles were unloaded. The
supplies were then cached, loaded onto watercraft, or man-portered
into South Vietnam.
Due to the increased effectiveness of "Commando Hunt", North
Vietnamese transportation units usually took to the roads only at dusk
with the peak in traffic coming in the early hours of the morning. As
American aircraft came on station, traffic would subside until just
before dawn, when fixed-wing gunships and night bombers returned to
their bases. The trucks then began rolling again, reaching another
peak in traffic around 06:00 as drivers hurried to get into truck
parks before sunrise and the arrival of the morning waves of U.S.
fighter bombers. By the last phase of "Commando Hunt" (October
1970–April 1972), the average daily number of U.S. aircraft flying
interdiction missions included 182 attack fighters, 13 fixed-wing
gunships, and 21 B-52s.
The evolution of
PAVN anti-aircraft weapons, 1965–1972.
The North Vietnamese also responded to the American aerial threat by
the increased use of heavy concentrations of anti-aircraft artillery.
By 1968 this was mainly composed of 37 mm and 57 mm
radar-controlled weapons. The next year, 85 mm and 100 mm
guns appeared, and by the end of Commando Hunt, over 1,500 guns
defended the system.
Of all the weapons systems used against the trail, according to the
official North Vietnamese history of the conflict, the AC-130 Spectre
fixed-wing gunship was the most formidable adversary. The Spectres
"established control over and successfully suppressed, to a certain
extent at least, our nighttime supply operations". The history
claimed that allied aircraft destroyed some 4,000 trucks during the
1970–1971 dry season, of which the C-130s alone destroyed 2,432
A countermeasure to the Spectre came on 29 March 1972, when a Spectre
was shot down on a night mission by a surface-to-air
SA-7 missile near
Tchepone. This was the first U.S. aircraft shot down by a SAM that
far south during the conflict.
PAVN responded to U.S. nighttime
bombing by building the 1,000 kilometer-long Road K ("Green Road")
from north of Lum Bum to lower Laos. During "Commando Hunt IV" (30
April through 9 October 1971), U.S., South Vietnamese, and Laotian
forces began to feel the North Vietnamese reaction to General Lon
Nol's coup in
Cambodia and the subsequent closure of the port of
Sihanoukville to its supply shipments. As early as 1969
begun its largest logistical effort of the entire conflict.
The Laotian towns of
Attapeu and Saravane, at the foot of the Bolaven
Plateau were seized by the North Vietnamese during 1970, opening the
length of the
Kong River system into Cambodia.
Hanoi also created the
470th Transportation Group to manage the flow of men and supplies to
the new battlefields in Cambodia. This new "Liberation Route"
turned west from the trail at Muong May, at the southern end of Laos,
and paralleled the
Kong River into Cambodia. Eventually this new route
extended past Siem Prang and reached the
Mekong River near Stung
PAVN took Paksong and advanced to Pakse, at the heart of
Bolaven Plateau region of Laos. The following year, Khong Sedone
fell to the North Vietnamese.
PAVN continued a campaign to clear the
eastern flank of the trail that it had begun in 1968. By 1968, U.S.
Special Forces camps at Khe Sanh and Khâm Đức, both of which were
used by MACV-SOG as forward operations bases for its reconnaissance
effort, had either been abandoned or overrun. In 1970, the same fate
befell another camp at Dak Seang. What had once been a
30-kilometre-wide (20 mi) supply corridor now stretched for
140 km (90 mi) from east to west.
PAVN victory (1971–75)
In early February 1971, 16,000 (later 20,000) ARVN troops rolled
across the Laotian border along Route 9 and headed for the PAVN
logistical center at Tchepone. "Operation Lam Son 719", the
long-sought assault on the
Ho Chi Minh
Ho Chi Minh trail itself and the ultimate
test of the American policy of Vietnamization, had begun.
Unfortunately for the South Vietnamese, U.S. ground troops were
prohibited by law from participation in the incursion, and the U.S.
was restricted to providing air support, artillery fire and helicopter
At first the operation went well, with little resistance from the
North Vietnamese. By early March 1971 the situation was changing.
Hanoi made the decision to stand and fight. It began to muster forces
which would eventually number 60,000
PAVN troops as well as several
Pathet Lao troops and Lao irregulars, outnumbering the
ARVN by almost three to one.
The fighting in southeastern Laos was unlike any yet seen in the
Vietnam War, since the
PAVN abandoned its old hit-and-run tactics and
launched a conventional counterattack. The
PAVN first launched massed
infantry attacks supported by armor and heavy artillery to crush ARVN
positions on the flanks of the main advance. Coordinated anti-aircraft
fire made tactical air support and resupply difficult and costly, with
108 helicopters shot down and 618 others damaged.
PAVN forces began to squeeze in on the main line of the advance.
Although a heliborne assault managed to seize Tchepone, it was a
useless victory, since the South Vietnamese could only hold the town
for a short period of time before being withdrawn due to attacks on
the main column. The only way the invasion force managed to extricate
itself from Laos was through the massive application of American
airpower. By 25 March 1971 the last ARVN troops recrossed the border,
closely followed by their enemy. As a test of Vietnamization, "Lam Son
719" failed; one-half of the invasion force was lost during the
South Vietnamese troops were poorly led and the elite Ranger and
Airborne elements had been decimated. "Lam Son 719" did manage to
postpone a planned
PAVN offensive against the northern provinces of
South Vietnam for one year. By spring 1972 the Americans and South
Vietnamese realized that the enemy was planning a major offensive, but
they did not know where or when. The answer came on 30 March 1972 when
PAVN troops, supported by more than 300 tanks crossed the
border and invaded Quảng Trị Province. The "Nguyen Hue Offensive"
(better known as the "Easter Offensive") was underway.
As South Vietnamese forces were on the verge of collapse, President
Richard M. Nixon
Richard M. Nixon responded by increasing the magnitude of the American
aerial assault (due to the withdrawal of U.S. aviation units from
Southeast Asia, squadrons were flown into South Vietnam from Japan and
the U.S. itself). The effort failed to halt the fall of Quảng Trị
City on 2 May, seemingly sealing the fate of the four northernmost
provinces. Due to the adoption of a conventional offensive (and the
logistical effort needed to support it),
PAVN placed itself squarely
in the sights of U.S. air power and the casualties were high.
[clarification needed]
The situation was complicated for the Americans by the launching of
two smaller attacks by the North Vietnamese: the first aimed to seize
Kon Tum in the Central Highlands, and threatened to cut South Vietnam
in two; the second prompted a series of savage battles in and around
An Lộc, the capital of Bình Long Province. A total of 14 PAVN
divisions were now committed to the offensive. On 13 May 1972, South
Vietnam launched a counteroffensive with four divisions backed by
massive U.S. air support. By 17 May, Quảng Trị City was retaken,
but the South Vietnamese military ran out of steam. The
against Kon Tum and An Lộc were contained. During these operations,
the North Vietnamese suffered approximately 100,000 casualties while
the South Vietnamese suffered 30,000 fatalities during the
The seizure of territory within South Vietnam itself allowed
extend the trail across the border with Laos and into that country.
The signing of the
Paris Peace Accords
Paris Peace Accords seemed to bring the conflict in
Southeast Asia to an end. The last U.S. forces departed in March 1973.
Both North and South Vietnamese were to maintain control in the areas
under their influence and negotiations between the two nations,
possibly leading to a coalition government and unification, were to
take place. Jockying for control of more territory, both sides
flagrantly violated the cease-fire and open hostilities began anew.
By 1973, the
PAVN logistical system consisted of a two-lane paved
(with crushed limestone and gravel) highway that ran from the mountain
passes of North Vietnam to the Chu Pong Massif in South Vietnam. By
1974 it was possible to travel a completely paved four-lane route from
the Central Highlands to Tây Ninh Province, northwest of Saigon. The
single oil pipeline that had once terminated near the A Shau Valley
now consisted of four lines (the largest eight inches in diameter) and
extended south to Lộc Ninh. In July 1973 the 259th Group as
redesignated the Truong Son Command, the regimental sectors were
converted to divisions, and the binh trams were designated as
regiments. By late 1974 forces under the new command included AAA
Division 377, Transportation Division 571, Engineering Division 473,
the 968th Infantry Division, and sectoral divisions 470, 471, and
Command then devolved upon Major General Hoàng Thế Thiện. In
December 1974 the first phase of a limited
PAVN offensive in South
Vietnam began. Its success inspired
Hanoi to try for an expanded
but still limited, offensive to improve its bargaining position with
Saigon. In March, General
Văn Tiến Dũng launched "Campaign 275",
the success of which prompted the general to push
Hanoi for a final
all-out offensive to take all of South Vietnam. After an
ineffective attempt to halt the offensive,
Saigon fell to North
Vietnamese forces on 30 April 1975.
Ho Chi Minh
Ho Chi Minh Highway
^ Military History Institute of Vietnam, Victory in Vietnam: The
Official History of the People's Army of Vietnam, 1954–1975 (trans.
by Merle Pribbenow, Lawrence, Kansas: University of Kansas Press,
2002, p. 28.
^ Robert J. Hanyok, Spartans in Darkness. Washington, D.C.: Center for
Cryptographic History, NSA, 2002, p. 94.
^ John Morocco, Rain of Fire, Boston: Boston Publishing Company, 1985,
^ Bernard C. Nalty. The War Against Trucks: Aerial
Southern Laos, 1968–1972. Washington, D.C.: Air Force History and
Museums Program, 2005, pp. 3–4.
^ John Prados, The Blood Road, New York: John Wiley and Sons, 1998, p.
^ For an overview of Laotian affairs in the late 1950s and early
1960s, see Arnold Isaacs, Gordon Hardy, MacAlister Brown, et al.,
Pawns of War. Boston: Boston Publishing Company, 1987, pp. 8–70.
^ Prados, p. 15.
^ a b Victory in Vietnam, p. 88.
^ In 1959 the North Vietnamese created Transportation Group 759, which
was equipped with twenty (20) steel-hulled vessels just to carry out
such infiltration. Victory in Vietnam, p. 88.
^ a b c d e f Brig. Gen. Soutchay Vongsavanh, RLG Operations and
Activities in the Laotian Panhandle. Washington, D.C.: United States
Army Center of Military History, 1980, p. 12.
^ Victory in Vietnam, p. 127.
^ Victory in Vietnam, p. 170.
^ Nalty, p. 295.
^ Jacob Van Staaveren,
Interdiction in Southern Laos, 1960–1968.
Washington, D.C.: Center for Air Force History, 1993, Appendix 5.
Actual figures from Prados, p. 45.
^ Van Staaveren, p. 97.
^ Van Staaveren, p. 104.
^ a b See Nina S. Adams and Alfred McCoy, eds., Laos: War and
Revolution, New York: 1970 and Arthur J. Dommen, Conflict in Laos: the
Politics of Neutralization, New York: 1971.
^ Two of the best works on the covert war in Laos are Kenneth Conboy
with James Morrison, Shadow War. Boulder, CO: Paladin Press, 1995 and
Roger Warner, Shooting at the Moon. South Royalton, VT: Steerforth
^ Van Staaveren, p. 44.
^ Morocco, p. 27.
^ Van Staaveren, p. 59 (Note: "Steel Tiger" was only one of several
escalatory actions approved under National Security Action Memorandum
^ Van Staaveren, p. 100.
^ Morocco, pp. 27–28.
^ Van Staaveren, pp. 226–228.
^ Van Staaveren, pp. 236– 239.
^ Conboy, pp. 85–91.
^ Conboy, pp. 115–122.
^ Military Assistance Command, Vietnam Command History 1965, Annex N,
^ Prados, p. 158.
^ John Schlight, A War Too Long: The USAF in Southeast Asia,
1961–1975. Washington, D.C.: Air Force History and Museums Program,
1996, p. 56.
^ America Takes Over, 1965–1967 by Edward Doyle, Samuel Lipsman, et
al. Boston: Boston Publishing Company, 1982, pp. 18–19.
^ Prados, p. 182.
^ The North by Edward Doyle, Samuel Lipsman, and Terrence Maitland.
Boston: Boston Publishing Company, 1986, p. 46.
^ Joint Chiefs of Staff, MACSOG Documentation Study, Appendix D, pp.
^ Victory in Vietnam, p. 208.
^ Doyle, Lipsman, and Maitland, p. 46.
^ Pike, Thomas (1969). Operations and Intelligence, I Corps Reporting:
February 1969. US Army. p. 193. ISBN 9781519486301.
^ An after-action Report dated 10 December 1968, signed by LTC Elvin
R. Heiberg III is available through the National Archives.
Declassified: Authority NND 873541.
^ Prados, p. 193.
^ Nalty, p. 37.
^ Prados, p. 303.
^ Earl H. Tilford, Setup: What the Air Force did in Vietnam and Why.
Maxwell Air Force Base, AL: Air University Press, 1991, p. 173.
^ Van Staaveren, pp. 255–283.
^ Prados, pp. 339–340.
^ Victory in Vietnam, p. 392.
^ a b Victory in Vietnam, p. 261.
^ a b Nalty, p. 218.
^ Herman L. Gilster, The Air War in Southeast Asia: Case Studies of
Selected Campaigns. Maxwell Air Force Base, AL: Air University Press,
1993, p. 21.
^ Prados, p. 313.
^ Victory in Vietnam, p. 262.
^ Prados, p. 369.
^ See William Shawcross's Sideshow: Kissinger, Nixon, and the
Destruction of Cambodia. New York: Washington Square Books, 1979, pp.
^ Gilster, p. 20.
^ Prados, p. 191.
^ Victory in Vietnam, p. 382.
^ See Maj Gen Nguyen Duy Hinh's Lam Son 719. Washington, D.C.: United
States Army Center of Military History, 1979; see also Prados, pp.
^ For American participation in the effort, see Keith W. Nolan, Into
Laos, Novato, California: Presidio Press, 1986.
^ David Fulghum, Terrence Maitland, et al., South Vietnam on Trial,
Boston: Boston Publishing Company, 1984, p. 75.
^ Nolan, p. 358.
^ Nolan, p. 359.
^ See Dale Andrade's Trial By Fire, New York: Hippocrene Books, 1995.
^ Fulghum and Maitland, p. 183.
^ Samuel Lipsman, Stephen Weiss, et al. The False Peace, Boston:
Boston Publishing Company, 1985, pp. 6–32.
^ Prados, p. 371
^ Marc Leepson, ed., Webster's New World Dictionary of the Vietnam
War. New York: Simon & Schuster Macmillan, 1999, p. 508.
^ Snepp, Decent Interval, New York: Random House, 1977; see also Clark
Dougan, David Fulghum, et al. (eds), The Fall of the South, Boston:
Boston Publishing Company, 1985.
^ Snepp, p. 225.
^ Snepp, pp. 133–35.
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Unpublished government documents
U.S. Military Assistance Command, Vietnam Studies and Observations
Group, Annex N, Command History 1965. Saigon, 1966.
Published government documents
Gilster, Herman L. The Air War in Southeast Asia: Case Studies of
Selected Campaigns. Maxwell Air Force Base: AL, Air University Press,
Military History Institute of Vietnam. Victory in Vietnam: The
Official History of the People's Army of Vietnam, 1954–1975. Trans
Merle L. Pribbenow. Lawerence KS: University of Kansas Press, 2002.
Nalty, Bernard C. The War Against Trucks, Aerial
Southern Laos, 1968–1972. Washington, D.C.: US Air Force History and
Museums Program, 2005.
Ngo, Lt. Gen. Quang Truong, The
Easter Offensive of 1972. Washington,
D.C.: United States Army Center of Military History, 1984.
Nguyen, Maj. Gen. Duy Hinh, Lam Son 719. Washington, D.C.: United
States Army Center of Military History, 1979.
Tranh, Brig. Gen. Dinh Tho, The Cambodian Incursion. Washington, D.C.:
United States Army Center of Military History, 1979.
Tilford, Earl H., Setup: What the Air Force did in Vietnam and Why.
Maxwell Air Force Base, AL: Air University Press, 1991.
Van Staaveren, Jacob.
Interdiction in Southern Laos, 1960–1968.
Washington, D.C.: Center for Air Force History, 1993.
Vongsavanh, Brig. Gen. Soutchay RLG Military Operations and Activities
in the Laotian Panhandle. Washington, D.C.: United States Army Center
of Military History, 1980.