Operation Commando Hunt was a covert U.S. Seventh Air Force and U.S. Navy Task Force 77 aerial interdiction campaign that took place during the Vietnam War. The operation began on 15 November 1968 and ended on 29 March 1972. The objective of the campaign was to prevent the transit of People's Army of Vietnam (PAVN) personnel and supplies on the logistical corridor known as the Ho Chi Minh Trail (the Truong Son Road to the North Vietnamese) that ran from southwestern North Vietnam through the southeastern portion of the Kingdom of Laos and into South Vietnam.

Interdiction (1964–1968)

Systematic U.S. aerial operations against the Ho Chi Minh Trail had begun on 14 December 1964 with Operation Barrel Roll.For a detailed history of the interdiction effort from 1961 to 1968, see Jacob Van Staaveren, Interdiction in Southern Laos, 1961–1968. Washington, D.C.: Center of Air Force History, 1993. With the onset of Operation Rolling Thunder, the strategic aerial bombardment of North Vietnam in April 1965, the U.S. also expanded its interdiction effort in Laos by dividing the Barrel Roll area into two sections on 3 April.John Morocco, Rain of Fire. Boston,: Boston Publishing Company, 1985, pp. 27–28. The former operation would continue in northeastern Laos while Operation Steel Tiger was initiated in the southern panhandle. The American headquarters in Saigon requested, and received, authorization to control bombing in the area adjacent to South Vietnam's northern provinces in Operation Tiger Hound on 3 December 1965.Van Staaveren, pp. 96–101.

The U.S. Air Force had already begun to up the ante in its anti-infiltration campaigns by unleashing B-52 Stratofortress bombers against the trail in December 1965.Morocco, p. 28. From April through June 1966 there were 400 B-52 anti-infiltration sorties against the system.John Schlight, A War Too Long, Washington, D.C.: Center for Air Force History, 1993 p. 55. The PAVN countered this effort by concentrating more anti-aircraft artillery weapons within its logistical network. Between 1964 and the end of 1967 there were 103,148 tactical air sorties launched against the trail, including 1,718 B-52 strikes.Van Staaveren, p. 287. During the same timeframe 132 U.S. aircraft or helicopters were shot down over Laos.Schlight, p. 58.

So matters stood until the massive PAVN/NLF Tet Offensive of early 1968. Although a tactical victory for American and South Vietnamese forces, Tet became a political disaster. The American public (who had been reassured by President Lyndon B. Johnson and the Pentagon that the communists were incapable of launching any such actions) were stunned by the size and ferocity of the offensive. The light at the end of the tunnel had been extinguished, if it had ever existed at all.For an overview of the offensive and its political repercussions, see Clark Dougan, Stephen Weiss, et al., Nineteen Sixty-Eight. Boston: Boston Publishing Company, 1983. The president, in an attempt to nudge Hanoi to the negotiating table, decreed an end to bombing operations in North Vietnam north of the 20th parallel, effectively ending Rolling Thunder on 11 November 1968.John Morocco, Thunder from Above: Air War, 1941–1968, Boston: Boston Publishing Company, 1984, pp. 183–184.

This effectively shifted the bombing campaign towards the southwest, in the direction of the Ho Chi Minh Trail. The interdiction campaign against the enemy logistics corridor was massively expanded due to the increased number of U.S. aircraft (approximately 500 planes) made available by the closure of Rolling Thunder. By November 1968 bombing missions over southern Laos had climbed by 300 percent, from 4,700 sorties in October to 12,800 in November.Earl H. Tilford, Setup: What the Air Force did in Vietnam and Why. Maxwell Air Force Base, Alabama: Air University Press, 1991, p. 173. By the end of the conflict, U.S. and South Vietnamese aircraft would drop over three million tons of ordnance on Laos, three times the total tonnage dropped on North Vietnam.Tilford, p. 173. The new campaign against the trail was unprecedented, and not just due to the numbers sorties flown or munitions expended. The U.S. was going to field its latest technology in its attempt to prevent the North Vietnamese from toppling the South Vietnamese government in Saigon.

Igloo White

As early as 1966 Secretary of Defense Robert S. McNamara had become increasingly disenchanted with the bombing of the north.Morocco, Thunder from Above, pp. 152–154. No amount of pressure, it seemed, could either drive Hanoi to the negotiating table or slow the flow of PAVN supplies and men to the south. He then began to consider an alternative in the form of a physical strongpoint/electronic barrier to infiltration that would stretch below the Demilitarized Zone from the coast to the Laotian frontier (and possibly beyond).Van Staaveren, pp. 255–266. This was the origin of the so-called "McNamara Line."

The physical barrier was to be backed up by air-dropped and hand-emplaced acoustic and seismic sensors that would provide both warning and location of enemy movements. A scientific group was established to find or develop the technology for what was initially titled Practice Nine. On 17 June 1967 the title of the program was altered to Illinois City and on 15 July to Dyemarker, the electronic barrier portion of which was designated Muscle Shoals. In June 1968 it was renamed for the last time, becoming Operation Igloo White.Van Staaveren, p. 269.

Igloo White consisted of three interrelated parts. The battery-operated sensors would be monitored by an airborne command and control center (ABCCC), which would relay the information to an infiltration surveillance center (ISC), located at Nakhon Phanom Air Base, Thailand. Computers at the ISC would collate and analyze the data and then relay target coordinates to the ABCCC which would, in turn, direct strike aircraft to the targets. The hand emplacement of sensors and bomb damage assessment missions were to be carried out by the reconnaissance teams of the highly classified Military Assistance Command, Vietnam Studies and Observations Group (SOG), which already operated "over the fence" in Laos. Construction began on the ISC on 6 July 1967 and was completed within three months.Van Staaveren, p. 271.

The anti-infiltration effort would be supported by MSQ-77 Combat Skyspot, a ground-based radar bombing system first introduced in Southeast Asia in 1966 to direct B-52 strikes in poor weather or in complete darkness.Bernard C. Nalty, The War Against Trucks: Aerial Interdiction in Southern Laos, 1968–1972. Washington, D.C.: Air Force Museums and History Program, 2005, p. 39. This system was utilized to direct one-quarter of all strike missions conducted by U.S. aircraft during the conflict.Schlight, p. 29. Combat Skyspot was complemented by expanding the radio-based LORAN system utilized by other strike aircraft.

A shakedown of the system took place during the first two weeks of November 1967 and it seemed to work.Van Staaveren, pp. 277–283. The PAVN siege of the U.S. Marines at the Khe Sanh Combat Base, in western Quang Tri Province, South Vietnam, provided the opportunity for an operational test. The American command in Saigon launched Operation Niagara, the largest tactical and B-52 operation thus far in the conflict, to support the Marines at Khe Sanh.Morocco, Thunder from Above, pp. 178–181. By the end of January 1968, Muscle Shoals had emplaced 316 sensors in 44 strings to detect PAVN troop movements in the vicinity of the combat base.Van Staaveren, p. 290. The operation was deemed a success, but locating and targeting enemy troops moving toward a fixed location like Khe Sanh was not the same as doing it on the Ho Chi Minh Trail.

And there were already problems with the system. The anti-personnel portion of the program had already failed. The presence and movements of enemy troops were to be detected by the utilization of small, wide-area Gravel mines that were to alert the acoustic sensors.Nalty, p. 20. The mines rapidly deteriorated in the heat and humidity of Laos, nullifying their effectiveness. The focus of any interdiction campaign, therefore, would have to concentrate on PAVN supply transportation. The war against trucks was about to begin.

1968 The immediate result of 11 November bombing halt was that the average daily sortie rate over southern Laos rose to 620 per day before the new campaign had even begun.Nalty, p. 48. The freeing of aircraft (Air Force, Navy, and Marine Corps) that had previously been participating in Rolling Thunder, when combined with those from Steel Tiger and Tiger Hound (which were both superseded by Commando Hunt), promised to create an interdiction effort of unprecedented scale. The new sensor-directed effort would see, for the first time, continuous round-the-clock bombing of the communist logistical system. During daylight, the missions would be performed by propeller-driven and jet fighter-bombers and B-52s. At night, fixed-wing gunships would prowl for prey. The new effort would also be supported by aerial defoliation missions (Operation Ranch Hand) and the cloud seeding weather modification effort known as Operation Popeye (see Ho Chi Minh Trail). On 15 November 1968 the Seventh Air Force was granted authorization for launch of Commando Hunt.Morocco, Rain of Fire, p. 40.

It was decided to divide Commando Hunt into numerically designated phases that reflected the seasonal weather patterns in southern Laos. Odd numbered campaigns took place during PAVN's high activity period, which occurred during the dry season (November–May). Even numbered campaigns took place during the more dormant wet season (June–October). It was never assumed that the campaigns would halt the North Vietnamese logistical effort, so the goals of the campaigns were limited. They were to have two objectives: First, to reduce the enemy's logistical flow by "substantially increasing the time needed to move supplies from North Vietnam to the south;" second, "to destroy trucks and supply caches along the roads, pathways, and streams and in the truck parks and storage areas along the Trail."Due to the failure of the anti-personnel portion of the system, the targets of Commando Hunt were trucks, the infrastructure of the trail (truck parks, supply caches, POL storage, etc.), the terrain itself (by creating landslides to destroy sections of the system), and finally, the ever-increasing numbers of North Vietnamese anti-aircraft weapons.

It was a daunting challenge. The Ho Chi Minh Trail (controlled by the 259th PAVN Logistical Group) consisted of a labyrinth of dirt roads, bicycle and foot paths, bypasses, storage areas, workshops, and truck parks that stretched from the mountain passes of North Vietnam, through the panhandle of Laos, and into east central Cambodia. The entire system was elaborately camouflaged from aerial observation and was constantly being maintained, expanded, and improved. By 1968 PAVN was relying less on manual labor and increasingly utilizing modern construction equipment. The CIA estimated during the year the 259th Group was using 20 bulldozers, eleven road graders, three rock crushers and two steamrollers on the network.Prados, p. 193. Manual labor was still provided by an estimated 40,000 to 50,000 Laotians (mostly pressed into service) and North Vietnamese volunteers.Morocco, Rain of Fire, p. 33.

1969