AIR POWER AND THE SIEGE OF KHE SANH
Bernard C. Nalty
Office of Air Force History
If I may resort to a cliche -- the phrase find, fix, and finish -- Operation Niagara represented an attempt to find and fix the enemy using ground forces and then finish him with aerial bombing and artillery. ". . . I gave it the code name Niagara," says the memoir of General William C. Westmoreland, "to invoke an image of cascading bombs and shells."1 The sparsely populated region around the Khe Sanh combat base in the northwestern corner of South Vietnam served as the site of Operation Niagara. Located near the village of Khe Sanh, the combat base sat atop a large hill mass that dominated a major highway leading into southern Laos and the enemy's north-south infiltration route, the Ho Chi Minh Trail. In late 1967 and the early weeks of 1968, Westmoreland was thinking of using Khe Sanh as the jumping-off place for an attack against the Ho Chi Minh Trail like that launched in 1971 by South Vietnamese troops.2
Finding the enemy proved to be no problem for the architects of Operation Niagara; indeed, scarcely had the Marines established themselves at Khe Sanh and made improvements to the airstrip, when the North Vietnamese appeared. Before the year 1967 ended, American intelligence detected signs that North Vietnamese forces were moving southward toward the Demilitarized Zone and Khe Sanh. Skirmishing began early in January 1968, and on the 20th a North Vietnamese officer, angered at being passed over for promotion, deserted and warned that his former comrades would attack the base and its Outposts that very night. As he predicted, infantry tried unsuccessfully to overwhelm the outpost on hill 861, northwest of the base, and occupied Khe Sanh village to the west, while artillery fire destroyed stockpiled fuel and ammunition at the base itself. Westmoreland seized the opportunity and directed his deputy commander for air, Air Force General William W. Momyer, to execute Operation Niagara. To fix the North Vietnamese so that the cascade of high explosive would have the deadliest effect, Lieutenant General Robert E. Cushman, Jr., the commanding general of the Marines in northern South Vietnam, reinforced the Khe Sanh garrison to a strength of about 6,000, flying in an additional Marine battalion on January 22 and a battalion of South Vietnamese rangers five days later.3
The tactics chosen for the defense of Khe Sanh were not new. In the fall of 1967, air strikes and counterbattery fire all but silenced the North Vietnamese artillery shelling the Marine combat bases at Con Thien and Gio Linh, northeast of Khe Sanh, nearer the South China Sea. General Momyer, who commanded the Seventh Air Force besides serving as Westmoreland's deputy for air, had already coined an acronym, SLAM, standing for Seek, Locate, Annihilate, and Monitor, to describe the use of ground and aerial reconnaissance and firepower to find, fix, and finish an enemy.
The B-52 bomber emerged as the key component in Momyer's SLAM concept, for this huge aircraft could carry as many as 108 500-pound bombs internally and on racks under the wings. A cell of three B-52s could saturate with high explosive an area measuring one by two kilometers, but the very size of the target box created a safety problem, even though the bombers released their loads on signal from a radar operator on the ground. At Con Thien planners imposed a safety margin of three kilometers between the impact area and friendly troops. Despite the reliance on radar, one of the 8-525 in action there dropped its bombs within the safety zone, where they exploded about 1.4 kilometers from the Marine bunkers, shaking the defenders, without causing injury, but detonating ammunition the enemy had stockpiled. This error demonstrated that the B-52s could bomb much closer than three kilometers without undue danger to friendly forces and that doing so was worthwhile, since the enemy was taking advantage of the safety zone to push his men and weapons forward and stock them with ammunition. During Operation Niagara, target boxes only one kilometer from the Khe Sanh combat base erupted suddenly, as bombs dropped from 25,000 feet, far beyond the reach of the available AAA, exploded on target.4
In terms of tonnage dropped and spectacular explosions, the B-52s made the greatest contribution to Operation Niagara. Before the eyes of the Marines at Khe Sanh, an entire tract one kilometer wide and two kilometers in length would dissolve in geysers of earth and smoke as the bombs detonated. Neither flesh nor steel, it seemed, could survive such a battering. The huge bombers dropped more than 59,000 tons of high explosive out of the 98,000tons of bombs and 160,000 artillery shells that deluged the enemy.5 Westmoreland credited the B-52s with making a critical contribution; indeed, he told the men of the 3d Air Division, who maintained and flew the bombers, that "the thing that broke their backs was basically the fire of the B-52s."6
This tribute to the B-52s should not, however, obscure the fact that fighter-bombers and attack aircraft of the Air Force, Navy, and Marine Corps combined to deliver the balance of the torrent of bombs, some 39,000 tons. If the B-52s served as Westmoreland's battle-ax, these smaller aircraft were his rapier. They thrust at compact targets too close to the combat base or its outposts for the use of B-52s; they suppressed enemy fire to enable transports to land at the Khe Sanh airstrip and helicopters to resupply the outposts; and, sometimes after dropping their bombs, they provided combat air patrols in the event North Vietnamese fighters should try to intervene.7
Since so much of the devastation, especially by B-52s, took place in areas that Marine patrols could not penetrate, aerial photographs produced most of the information used to assess the effect of the bombing and shelling. Largely on the basis of collapsed trenches, damaged artillery pieces, and demolished bunkers, Westmoreland's intelligence specialists credited Operation Niagara with killing or wounding 10,000 NVA, a total that represents little more than an educated guess.8
The camera also helped locate targets for air strikes or artillery; however, in the selection of targets, electronic sensors demonstrated their value in an operation for which they were not really intended. The initial plan called for them to detect North Vietnamese infiltration by road and trail into South Vietnam and report the enemy's movement to an infiltration surveillance center at Nakhon Phanom, Thailand, which would call for air strikes. Instead, the sensors now kept watch beyond the hills and ridges around Khe Sanh and reported through the surveillance center to a fire support coordination center at the base. Some 250 of the electronic devices, dropped by aircraft, monitored the routes the enemy was likely to use. pebble-sized mines detonated when stepped on and triggered the individual sensors to broadcast a signal to the surveillance center, where analysts interpreted the data and alerted the combat base to patterns of hostile activity.9
The massive use of firepower that constituted Operation Niagara tended to overshadow the role of transports and helicopters, usually escorted by fighter-bombers or attack aircraft, in supplying the Khe Sanh Combat Base and its outposts. Lockheed C-130s and Fairchild C-123Ks of the Air Force delivered more than 4,000 tons of cargo and 2,600 persons to Khe Sanh and carried out some 1,500 passengers, including 306 wounded men. In addition, the C-130s parachuted another 8,000 tons of cargo to the defenders. Marine helicopters hauled 4,600 ton, of cargo and 14,500 passengers, usually on shuttle flights to and from the hilltop outposts.10
Operation Neutralize, the attack on the North Vietnamese batteries shelling Con Thien and other Marine Corps outposts south of the Demilitarized Zone, provided a precedent for the massing of air power and artillery in defense of a base, and the operation also foreshadowed the problems of coordinating these weapons within a confined space, as at Khe Sanh. During Neutralize, to minimize the danger of collision between Air Force aircraft and Marine Corps artillery shells or airplanes, Momyer had sent a liaison team to the control center operated at Dong Ha by the 3d Marine Division.11 Facing a similar problem of coordination at Khe Sanh in January 1968, Momyer proposed to do more than merely send a liaison party. He intended, he said, to "get the air responsibilities straightened out as we had them in Korea and World War II."12
By "straightened out," Momyer meant that he should assume operational control over Marine Corps tactical aircraft. During World War II, in the Solomons, an officer of the Army Air Forces had exercised operational control over Navy and Marine Corps aviation units; but the converse was equally true, for in the Central Pacific, on Okinawa, and at times in the Solomons, Marine Corps or Navy airmen had controlled elements of the Army Air Forces. In Korea, poor communications frustrated early attempts to give the commander, 5th Air Force, "coordination control" over Marine aviation. Eventually a joint operations center received nominal control over tactical support by Air Force and Marine Corps squadrons, but this agency actually exercised its authority through the commander of the 1st Marine Aircraft Wing, who made the final decision how to use his resources. The Marines, however, objected even to this degree of control, arguing that aviation formed an integral part of an air-ground team; no outside headquarters, they said, should have the ability, however seldom it might be used, to divert aircraft from battlefield targets chosen by the Marines.13
On January 18, 1968, Westmoreland advised Admiral U. S. Grant Sharp, the Commander in Chief, Pacific, that he intended to assign Momyer greater control over Marine Corps aviation during the impending fight for Khe Sanh. Sharp, however, advised against a sudden move because of the possible adverse impact on interservice relations. As a result, Momyer had to settle for less, negotiating an agreement, based partly on geography, that introduced an Air Force airborne battlefield command and control center into the control network. The command and control mechanism adopted on January 21, at the outset of the battle, adhered to the principle that a Marine control agency should handle the strikes nearest the base, while the Air Force airborne battlefield command and control center directed aircraft against more distant targets. Since aircraft attacking close to the base and its outposts ran the risk of straying into the path of artillery shells, the fire support coordination center at Khe Sanh, which meshed artillery and air support, could veto any close-in air strikes.14
The arrangement adopted in January, essentially a compromise, satisfied neither Momyer nor the Marine Corps. The Air Force general protested that Marine airmen were ignoring the airborne battlefield command and control center, and to remedy this he called during February for adoption of a "single manager system" in which all requests for tactical air support would be routed through the Seventh Air Force control center. As single manager he would be able to obtain the greatest efficiency and economy of force in apportioning air power among targets at Khe Sanh, in the northern provinces of South Vietnam, throughout the rest of that country, and in the adjacent portions of southern Laos and North Vietnam. Whereas Momyer thought in terms of using a limited number of aircraft to attack an increasing number of targets over a wide area, the Marines focused on providing the swiftest and deadliest support for the man with the rifle. They insisted that the presence of the airborne battlefield command and control center already impeded their ability to respond; any requirement to channel requests for air support through a single manager would, they maintained, result in worse delays and the possible mismatching of munitions to targets.15
This time Admiral Sharp accepted Momyer's reasoning. When Westmoreland asked to appoint a single manager for Air Force and Marine Corps tactical aviation, the admiral approved, justifying his decision on the grounds that the northern provinces of South Vietnam no longer formed a Marine Corps sector. Westmoreland had moved Army forces northward and established the equivalent of a corps headquarters to control them. Momyer formally became the single manager for air on March 7, but the new system did not become fully operational until the 22d. By the time the impact of centralized management began to be felt, the North Vietnamese were pulling back from around Khe Sanh; the principle of a single manager had no effect on the outcome of the battle that occasioned its introduction. The Marine Corps protested the new policy all the way to President Lyndon Johnson, who upheld Sharp and Westmoreland. In actual practice, however, the Seventh Air Force soon began releasing blocks of sorties to the Marines, at first to escort helicopters but later to use as they saw fit. Within a year, the techniques of control actually in use closely resembled the arrangement in Korea 20 years earlier, which was not the kind of highly centralized system that Momyer had described.16
Although hailed by General Westmoreland as a victory won largely by the firepower of the B-52s, Operation Niagara no longer seems the classic example of the successful use of air power, including air transport, in the defense of a beleaguered base. Indeed, doubts have arisen about the enemy's intentions. Did Vo Nguyen Giap, the senior North Vietnamese general, actually plan a second Dien Bien Phu, a true battle of annihilation, as Westmoreland insisted? A number of considerations suggest that Giap actually was trying to lure American troops away from the cities, which were the objectives of the Tet Offensive. For one thing, the North Vietnamese did not attempt to cut off the flow of water to the base, although they might have dammed or polluted the single stream. For another, according to Peter Braestrup, a journalist who studied the battle and its coverage by the American news media, the enemy subjected Khe Sanh to a reasonably light bombardment, except on February 23, when some 1,300 artillery and mortar shells exploded on the base. Braestrup also believes that Giap would have deployed additional antiaircraft guns to cover the approaches to the airstrip in preparation for an assault. At Dien Bien Phu, after all, the North Vietnamese general had shut down the airstrip entirely and disrupted attempts by the French to supply their troops by parachute; surely he would have done as much if he had been intent upon seizing Khe Sanh.17 On the other hand, those who believe that American firepower frustrated another Dien Bien Phu can cite the large number of hostile troops massed in the vicinity of Khe Sanh, far too many, if intelligence estimates were correct, to serve merely as decoys. Moreover, the bombardment of February 23 preceded a flurry of enemy activity that, thanks in part to the electronic sensors, brought down a deluge of American bombs and shells. This violent reaction could conceivably have thwarted the opening moves in an attempt to overwhelm the base.18
Uncertainty also clouds the destructive effects of Operation Niagara. The estimates of enemy casualties are imperfect at best. As was true throughout the Vietnam War, it was easier to measure effort than results; indeed, the scope of the operation may well have influenced the estimate of the effects. Since a torrent of high explosive inundated the enemy, his losses had to be disastrous.19
One thing that can be said for certain is that the single manager took control of tactical aircraft too late to have any impact on the defense of Khe Sanh. Moreover, the single manager system achieved true centralization for a very brief time, if at all. Referring to operations in the summer of 1969, a senior Marine airman, Major General Charles Quilter, said that "we hardly . . . knew of single management because we got everything we wanted."20
If the Marines got what they wanted, and the Air Force did not need to ration air power, what was the point of the single manager system? I suggest this interpretation. Tactically, the single manager meant nothing. Doctrinally, however, it affirmed a principle, centralized control, that the Army Air Forces and the U.S. Air Force had consistently championed, and in doing so, it established a precedent for the future.
1. William C. Westmoreland, A Soldier Reports (Garden City, NY: Doubleday, 1976), p. 412.
2. Ibid., pp. 408-409; Phillip B. Davidson, Vietnam at War: The History. 1946-1975 (Novato, CA: Presidio Press, 1988), p. 496.
3. Davidson, Vietnam at War, pp. 501-502; Moyers Shore, II, The Battle for Khe Sanh (Washington: Historical Branch, G-3, Headquarters USMC, 1969), pp. 31-39.
4. Hist, 3d Air Division, July-December 1967, exhibits 191 and 192; Westmoreland, A Soldier Reports, pp. 246-248; John Schlight, The United States Air Force in Southeast Asia: The War in South Vietnam: The Years of the Offensive. 1965-1968 (Washington: Office of Air Force History, 1988), pp. 269-271.
5. Dir/Ops, HQ USAF, "Trends, Indicators, Analyses," July 1968, p. II: 2; Shore, Khe Sanh, pp. 106-107; 1st MAW Command Chronology, March 1968, pp. 11:2.
6. Hist, 3d Air Division, Jan-Jun 68, exhibit 180.
7. See footnote 5.
8. Hist, USMACV, 1968, Vol. I, pp. 423-424.
9. Hearing before the Electronic Battlefield Subcommittee of the Preparedness Investigating Subcommittee of the Senate Committee on Armed Services, 91st Congress, 2d Session, Investigation into the Electronic Battlefield Program, pp. 84-85, 88, 110-111; intvw, Bernard C. Nalty and Charles W. Hildreth with Colonel William L. Walker, USAF, Dir/Int, Task force Alpha (which operated the infiltration surveillance center), June 8, 1971.
10. Bruce W. Pollica and Joe R. Rickey, 834th Air Division Tactical Airlift Support for Khe Sanh, January 21-April 8, 1968, pp. 15, 86; Shore, Khe Sanh, pp. 76-89.
11. Schlight, Years of the Offensive, p. 270.
12. Robert M. Burch, Single Manaoer for Air in SVN (HQ PACAF, Project CHECO, March 18, 1969), p. 5.
13. Robert F. Futrell, The United States Air Force in Korea. 1950-1953 (Washington: Office of Air Force History, reprinted 1983), pp. 212-214, 490-491, 706-707; Lynn Montross, Hubbard D. Kuokka, and Norman Hicks, U.S. Marine Corps Operations in Korea, 1950-1953, Vol. IV, The East-Central Front (Washington: Historical Branch, G-3, HQ USMC, 1962), pp. 15-18.
14. Schlight, The Years of the Offensive, pp. 285-286.
15. Warren A. Trest, Single Manager for Air in SVN (HQ PACAF, Project CHECO, July 1, 1968), pp. 25, 27-28, 82-83.
16. Schlight, The Years of the Offensive, p. 256; Charles R. Smith; U.S. Marines in Vietnam: High Mobility and Standdown, 1969 (Washington: History and Museums Division, HQ USMC, 1988), pp. 224-226.
17. Davidson, Vietnam at War, pp. 510-512; Peter Braestrup, Big Story: How the American Press and Television Reported and Interpreted the Crisis of Tet 1968 in Vietnam and Washington (Boulder, CO: Westview Press, 1977), Vol. I, pp. 346-348, 350.
18. Davidson, Vietnam at War, pp. 504, 508.
19. Robert Pisor, The End of the Line: The Siege of Khe Sanh (New York: W.W. Norton, 1982), pp. 262-263.
20. Smith, High Mobility and Standdown, p. 225.