Ho Chi Minh trail
The Ho Chi Minh Trail, also called Annamite Range Trail was a logistical network of roads and trails that ran from North Vietnam to South Vietnam through the kingdoms of Laos and Cambodia. The system provided support, in the form of manpower and materiel, to the Viet Cong and the People's Army of Vietnam, during the Vietnam War. Construction for the network began following the North Vietnamese invasion of Laos in July 1959. At the time it was believed to be the main supply route, however it later transpired that the Sihanouk Trail which ran through Cambodia was handling significantly more material.
It was named by the U.S. after the North Vietnamese leader Hồ Chí Minh. The origin of the name is presumed to have come from the First Indochina War, when there was a Viet Minh maritime logistics line called the "Route of Ho Chi Minh". Shortly after late 1960, as the present trail developed, Agence France-Presse announced that a north–south trail had opened, naming the corridor La Piste de Hồ Chí Minh, the 'Hồ Chí Minh Trail'. The trail ran mostly in Laos, and was called the Trường Sơn Strategic Supply Route by the communists, after the Vietnamese name for the Annamite Range in central Vietnam. They further identified the trail as either West Trường Sơn or East Trường Sơn. According to the U.S. 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". The trail effectively supplied troops fighting in the south — an unparalleled military feat, considering it was the site of the single most intense air interdiction campaign in history.
Origins (1959–1965)
Parts of what became the trail had existed for centuries as primitive footpaths that enabled trade. The terrain was among the most challenging in Southeast Asia, a sparsely populated region of rugged mountains in elevation, triple-canopy jungle and dense tropical rainforests. Pre-First Indochina War, the routes were known as the "Southward March", "Eastward March", "Westward March", and "Northward March". During the First Indochina War the Việt Minh maintained north–south communications and logistics by expanding on this system of trails and paths, and called the routes the "Trans-West Supply Line" and the "Trans-Indochina Link".In May 1958 PAVN and Pathet Lao forces seized the transportation hub at Tchepone, on Laotian Route 9. Laotian elections in May brought a right-wing government to power in Laos, increasing dependence on U.S. military and economic aid and an increasingly antagonistic attitude toward North Vietnam.
PAVN forces, alongside the Pathet Lao, invaded Laos on 28 July 1959, with fighting all along the border with North Vietnam against the Royal Lao Army. In September 1959, Hanoi established the 559th Transportation Group, headquartered at Na Kai, Houaphan province in northeast Laos close to the border. It was under the command of Colonel Võ Bẩm and established to improve and maintain a transportation system to supply the VC insurgency against the South Vietnamese government. Initially, the North Vietnamese effort concentrated on infiltration across and immediately below the Vietnamese Demilitarized Zone that separated the two Vietnams. The 559th Group "flipped" its line of communications to the west side of the Trường Sơn mountains.
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. At the time, Hanoi could supply its southern allies much more efficiently by sea. In 1959 the North Vietnamese created Transportation Group 759, which was equipped with 20 steel-hulled vessels to carry out such infiltration.
After the initiation of U.S. naval interdiction efforts in coastal waters, known as Operation Market Time, the trail had to do double duty. 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 VC and PAVN forces seeking respite and resupply after conducting operations in South Vietnam.
Base areas
There were five large base areas in the panhandle of Laos. BA 604 was the main logistical center during the war. From there, the coordination and distribution of men and supplies into South Vietnam's Military Region I and BAs further south was accomplished.- BA 611 facilitated transport from BA 604 to BA 609. Supply convoys moved in both directions. 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 moving men and materiel into MR 2 and to the B-3 Front.
- BA 609 was important due to a fine road network that made it possible to transport supplies during the rainy season.
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, engineering, and communications functions, a "Binh Tram" provided the logistical necessities. Usually located one day's march from one another, communication-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."
There were nine Binh Trams between the dry season of 1967 to August 1968. An example is Binh Tram 31:
The system developed into an intricate maze of dirt roads, 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 improved. 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 surface.
The weather in southeastern Laos came to play a large role both in the supply effort and in U.S. and South Vietnamese efforts to interdict it. The southwest monsoon from mid-May to mid-September, brought heavy precipitation. The sky was usually overcast with high temperatures. The northwest monsoon, from mid-October to mid-March was relatively dry with lower temperatures. Since the road network in the trail system was generally dirt, the bulk of supply transport, 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 season.
Interdiction and expansion (1965–1968)
In 1961 U.S. intelligence analysts estimated that 5,843 enemy infiltrators had moved south on the trail; in 1962, 12,675 ; in 1963, 7,693 ; 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 PAVN soldiers 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.U.S. Defense Intelligence Agency analysts concluded that during the 1965 Laotian dry season the enemy was moving 30 trucks per day over the trail, far above the Saigon estimate.
U.S. officials had only estimates of its enemy's capabilities; intelligence collection agencies often conflicted with each other. Thanks to improvements to the trail system, the quantity 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. This did not prevent the North Vietnamese from violating Lao 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 constant bombing of the trail. They also provided support for the Lao government.
Air operations against the trail
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 approved 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 Saigon requested 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 Tiger Hound".
Political considerations complicated aerial operations. But the seasonal monsoons that hindered communist supply operations in Laos also hampered the interdiction effort. These efforts were hindered 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 USAF undertook two experimental operations that it hoped would worsen the monsoons. "Project Popeye" was an attempt to indefinitely extend the rainy season 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. Fifty-six 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 the second operation, "Project Commando Lava", began on 17 May: scientists from Dow Chemical had created a chemical concoction that, when mixed with rainwater, destabilized the soil and created mud. The program drew enthusiasm from its military and civilian participants, who claimed that they were there to "make mud, not war." In some areas it worked, depending on the makeup of the soil. The chemicals were dropped by C-130A aircraft, but the overall effect on North Vietnamese interdiction was minimal and the experiment was cancelled.