The prevailing military wisdom going into the 1960s was that the United States should not get bogged down in a ground war in Asia. This admonition was well known to policy-makers in the White House and the Pentagon as they struggled with the impending problem of Vietnam.
In late April of 1961, the new President, John F. Kennedy, was cautioned again by Gen. Douglas MacArthur, who had fought two wars in the Pacific and Far East. MacArthur told Kennedy it would be a mistake to commit American soldiers on the Asian mainland.
Nevertheless, two weeks later, JFK’s National Security Council asked the Joint Chiefs of Staff to examine “the size and composition of forces which would be desirable in the case of a possible commitment of US forces to Vietnam.” The Chiefs estimated that “40,000 US forces will be needed to clean up the Viet Cong threat.”
US involvement began as advice and training for the South Vietnamese armed forces but the mission expanded. In mid-1965, the United States plunged into what it had so often been warned against—a land war in Asia. By the end of 1965, there were 155,000 US troops on the ground in South Vietnam, with more on the way.
By decree from Washington, the “In-Country” War in South Vietnam took precedence over all other efforts in Southeast Asia. The air campaign against North Vietnam, the interdiction of the Ho Chi Minh Trail, and the “secret war” in Northern Laos were strictly secondary to the ground war in South Vietnam.
The In-Country War was run by the Army. The other services—primarily the Air Force—flew hundreds of thousands of sorties in support of the ground war, but they had little say in the strategy.
“The US military strategy employed in Vietnam, directed by political decisions, was essentially that of a war of attrition,” said Army Gen. William C. Westmoreland, commander of Military Assistance Command Vietnam, MACV.
The assumption was that “search and destroy” operations could win the war in the South by inflicting more casualties than the enemy was prepared to withstand. Westmoreland—who devised the attrition strategy—dismissed any concern about “Asia’s legendary hordes of manpower” and said the war in Vietnam was against “an enemy with relatively limited manpower.”
Despite assurances from the White House and MACV that the war was going well, progress was difficult to see, and after the Tet Offensive of 1968, the attrition strategy lost whatever credibility it might once have had.
Tet, envisioned by North Vietnam as a master stroke to end the war, was a colossal military failure for the communists. Despite that, it was the turning point of the war. The scope and strength of the offensive, amplified by graphic news reports flowing back to the United States, undercut public confidence and support for the war.
After Tet, the United States made no serious attempt to win. The driving objective became “peace with honor,” which meant settling with the enemy and getting out of Vietnam. Withdrawal of US ground troops began in July 1969.
Vietnam came along just after the Kennedy Administration introduced “Flexible Response” in 1961. Flexible Response was not a highly developed doctrine but was more a concept or even a philosophy of conflict. Its emphasis was on having a number of military options—particularly conventional options—with which to meet a crisis. It was the seedbed of “limited war.”
Flexible Response was based in considerable part on the theories of retired Gen. Maxwell D. Taylor, the former Army Chief of Staff.
Taylor had been opposed to the Eisenhower Administration’s doctrine of Massive Retaliation and the associated prominence of the Air Force in national strategy. He resigned and wrote An Uncertain Trumpet, published in 1959. It called for more emphasis on non-nuclear, limited war and a much bigger role for the ground forces. Kennedy read the book and was impressed. Taylor’s concept of flexible response seemed to fit with the challenges emerging in Southeast Asia.
The Soviet Union had already declared its support for “wars of national liberation.” Insurgency in South Vietnam was of particular concern. In 1961, the White House ordered the armed services to develop capabilities to defeat counterinsurgency and dispatched special forces, including a detachment of air commandos, to assist the South Vietnamese government.
Kennedy in 1961 recalled Taylor to active duty, and in 1962 he became Chairman of the Joint Chiefs of Staff. MACV was established in 1962 as a subunified command of US Pacific Command. Second Air Division, which later became 7th Air Force, was also activated as the air arm of MACV.
Gen. Curtis E. LeMay, the Air Force Chief of Staff, argued without success that the locus of the war was in North Vietnam, not in the South, and declared, “We should stop swatting flies and go after the manure pile.”
Gulf of Tonkin Incident
US forces, supposedly limited to training and support, engaged routinely in combat on a clandestine basis during the “advisory” period. The combat role broke into the open in 1964 when US naval vessels were attacked in the Gulf of Tonkin by North Vietnamese patrol boats, and the Air Force moved fighters and bombers into Southeast Asia.
In response to attacks on air bases in South Vietnam, US Air Force and Navy airmen struck selected targets in North Vietnam. They began with small-scale reprisal raids and escalated in March 1965 to Operation Rolling Thunder, sustained air strikes against the North.
On March 8, a week after Rolling Thunder began, two battalions of US marines landed at Da Nang to defend the US air base there. For the moment, they had no other mission.
During the 1964 election campaign, President Lyndon B. Johnson had declared that “we are not about to send American boys nine or ten thousand miles away from home to do what Asian boys ought to be doing for themselves.” Six months later, he would reverse his position and send American troops to Vietnam.
The opening rounds of Rolling Thunder did not amount to much. There were not many sorties flown and the targets were chosen by officials in Washington—who were more interested in sending signals than in fighting a war—to be as nonprovocative as possible. Adm. U.S. Grant Sharp, commander of US Pacific Command, said the bombing was “completely insignificant.” He added, “The North Vietnamese probably didn’t even know the planes were there.”
The politicians gave this weak-willed effort less than a month before they decided that Rolling Thunder was a failure and shifted to a ground option. On April 1, the White House changed the mission of the marines at Da Nang from defense of the air base to “more active use” and directed that “premature publicity be avoided” to “minimize any appearance of sudden changes in policy.”
At a conference in Hawaii April 20, Secretary of Defense Robert S. McNamara declared that henceforth the emphasis would be on the ground war in the South. The air campaign against the North would continue, but as a secondary priority. Targets in the South would take precedence, and if need be, airpower sorties would be diverted from the North to fill the requirement.
“This fateful decision contributed to our ultimate loss of South Vietnam as much as any other single action we took during our involvement,” Sharp said.
Westmoreland, assigned the lead role by Johnson and McNamara, was ready to move ahead. In July, the President approved Westmoreland’s request for 44 Army battalions in South Vietnam. According to the Pentagon Papers, an internal DOD history of the war, that commitment “was perceived as a threshold—entrance into Asian land war.” The 44 battalions were a down payment on a ground force that would eventually grow to 450,000 troops.
“I knew … that I was flouting the shibboleth of avoiding a ground war in Asia,” Westmoreland said, “yet I recognized that that shibboleth was subject to modification in terms of the nation’s objectives, as it had been modified in the past.”
The first approach to employing the ground force was the “enclave strategy,” advocated by Taylor, who by that time had become US ambassador to South Vietnam. Under that concept, US troops would occupy secure enclaves along the coast and range out as far as 50 miles for selected operations, after which they would return to the enclaves. Other ground force action would be the job of the South Vietnamese army.
Westmoreland did not like the enclave strategy and he managed to replace it with “search and destroy” operations in which US troops could be deployed anywhere MACV wanted them to go. The main objective was to eliminate large enemy units. “It was, after all, the enemy’s big units—not the guerillas—that eventually did the South Vietnamese in,” Westmoreland said in his memoirs.
It soon boiled down to a war of attrition in which MACV used “body counts,” “kill ratios,” and other measures in its attempt to quantify the progress. However, the expectation of wearing down the enemy turned out to be wrong. North Vietnamese and Viet Cong fighting strength kept increasing instead of decreasing. MACV had critically misjudged the staying power of the adversary.
“In any case,” Westmoreland said, “what alternative was there to a war of attrition? A ground invasion of North Vietnam was out.” The White House would not approve a more aggressive approach for fear that China or even the Soviet Union might be drawn into the war. Disengagement was not an option either.
Gen. John P. McConnell, who had replaced LeMay as Air Force Chief of Staff, argued for an air strategy, but he was no more successful than LeMay had been. The official view was that the place to win the war was on the ground in the South.
The Rolling Thunder air campaign against the North continued, but it was hamstrung by all manner of political constraints and prohibitions. McNamara “insisted that the requirement for airpower in South Vietnam must get the first call on our air assets,” Sharp said. “Air assets programmed for attacks in the North would be diverted to satisfy the needs in the South.”
“The only aspect of the war in which we had the initiative was our air campaign against the North Vietnamese heartland,” said Gen. William W. Momyer, who took over 7th Air Force in 1966. “On the ground in South Vietnam, the North Vietnamese had the initiative since their forces could fight when they wanted and retreat into the jungle or into sanctuaries in Laos or Cambodia when they didn’t.”
There was no requirement in South Vietnam to establish air superiority—enemy aircraft did not operate there—and there were no strategic targets. The Air Force mission was supporting the Army and servicing the Army’s target list.
MACV headquarters spent 80 percent of its time on Army matters. Westmoreland made no pretense that it was a joint force operation.
“Aware that my deputy might have to succeed me, I resisted pressure from the Air Force for my deputy to be an air officer,” Westmoreland said. “Why place an air officer in a position where he might have to run what was essentially a ground war? I similarly resisted pressures for an equal-quota system for officers of the various services on the MACV staff.”
MACV, however, did not control the entire war. Westmoreland’s authority was limited to South Vietnam and control of air strikes in adjacent territory designated as extensions of the battle in South Vietnam.
Sharp, the airpower-minded commander in chief of PACOM, wanted the air war in North Vietnam and Laos to be conducted by his two component commands, Pacific Air Forces and the Pacific Fleet. When directing out-of-country operations, 7th Air Force reported to PACOM through PACAF. Westmoreland, with his parochial focus on the ground, was not in the chain of command.
Nevertheless, McNamara had made those operations subordinate to the In-County War. Thus, as historian John Schlight has aptly noted, Westmoreland “had veto power over bombing, interdiction, and reconnaissance programs outside South Vietnam, many of which were PACAF programs the Air Force believed should have higher priority.”
Sharp reported, “Any request by Westmoreland for more airpower always got a sympathetic hearing from the Secretary of Defense, who was determined that all in-country requirements would be satisfied, no matter how inflated they were, before we used any effort against North Vietnam. His priorities for air strikes were (1) South Vietnam, (2) Laos, and (3) North Vietnam—and North Vietnam was a very poor third.”
But, Schlight said, “not all kinds of missions in the South were of equal importance. First priority must go to supporting ground troops actually engaged with the enemy. After this, airpower could be used for prestrikes and air cover for units carrying out major ground operations. Escort for trains and convoys came next. Planes could be used for interdiction outside South Vietnam only after these close air support needs were met.”
The Navy refused to put a Navy component at MACV, but its aircraft, flying off carriers at Dixie Station in the South China Sea, did operate under the control of 7th Air Force when they flew missions in South Vietnam. Until late in the war, the land-based Marine Corps fighters in South Vietnam were controlled by the Marine Corps commander on the ground, not by 7th Air Force.
Most air attack missions in the South were directed by a forward air controller, an Air Force pilot flying a light spotter airplane over territory he knew very well and marking targets with smoke rockets for the strike aircraft. FACs reported to air liaison officers, who were attached to the Army.
It was not until July 1972 that Air Force Gen. John W. Vogt Jr., the sixth and last commander of 7th Air Force, finally became the deputy commander of MACV. By then, nearly all of the US ground combat forces in Vietnam had gone home, so MACV was not conceding all that much.
At peak deployment in 1968, the Air Force had 56 squadrons and 1,200 aircraft based in South Vietnam. In the beginning, the air commandos had flown only propeller-driven airplanes. When the Air Force first employed jet aircraft in South Vietnam in 1965, there were only three airfields—Da Nang, Bien Hoa, and Tan Son Nhut airport in Saigon—capable of handling jets. That infrastructure soon grew to 10 major air bases.
Air support was crucial as the Army began deploying to Vietnam in 1965 but had not yet achieved full strength. In October 1965, repeated air strikes by the Air Force and the Navy kept two regiments of the North Vietnamese Army, augmented by Viet Cong irregulars, from overrunning allied ground forces in the Ia Drang Valley in the Central Highlands.
By 1968, the Air Force had supported the ground forces in 75 large battles and in hundreds of smaller ones. Almost every kind of aircraft in the USAF inventory that could carry weapons or be adapted to do so saw action. In addition to the support strikes by US fighters, light bombers, and gunships, Strategic Air Command B-52s flew almost 125,000 Arc Light bombing missions in Southeast Asia, more than half of them in South Vietnam.
Attack sorties, however, accounted for only about 20 percent of the sorties the Air Force flew in South Vietnam. By far, the biggest mission was airlift, which accounted for about 51 percent of the total. Reconnaissance accounted for another 20 percent or so. The remainder of the sorties were various kinds of combat support, including combat search and rescue.
“Ninety percent of the ground battles in South Vietnam were fought without the benefit of tactical air support,” said historian Schlight. “One reason for this was that half of all ground contacts lasted less than 20 minutes, too short a time to bring airpower to bear.”
About 70 percent of the Air Force strike support sorties were of the “preplanned” variety. The mission was planned ahead of time, the pilots were briefed on the target area, and the aircraft were loaded with the best munitions for the job.
The strong preference of the troops on the ground, though, was for “operations immediate” strikes, in which the aircraft came in response to a call for help. A fighter sitting ground alert could be there in 35 to 45 minutes. An aircraft diverted from another mission might arrive in 20 minutes or less, in time to cover a firefight.
Most targets of substance could wait the 40 to 45 minutes for alert aircraft to respond. “Usually a ground force commander took longer than this to decide to call for air support rather than handle the situation with organic weapons or artillery,” Momyer said.
The most spectacular engagements of airpower in the In-Country War were when the North Vietnamese Army invaded the South in strength in 1968 and in 1972.
After years of sapper attacks and hit-and-run operations in the jungle, the North Vietnamese made a major change in strategy with the Tet Offensive of 1968. It was planned and directed by Gen. Vo Nguyen Giap, hero of the defeat of French colonial forces at Dien Bien Phu in 1954. It was timed to catch the US and South Vietnamese forces off guard at Tet, the most important holiday in Vietnam, and it was supposed to be a master stroke that would win the war for the North.
On Jan. 20, the North Vietnamese struck the US Marine Corps base at Khe Sanh, an isolated outpost near the Demilitarized Zone. Giap’s intention, apparently, was to create a diversion that would screen the coming Tet attacks as well as neutralizing the Khe Sanh garrison as a counter to Giap’s forces that would be moving South for the invasion.
Saving Khe Sanh
Khe Sanh depended on airpower, both for defense and resupply. It was easy for the North Vietnamese to cut off ground access. The base had no strategic value except as a staging area from which the marines conducted operations. When the North Vietnamese laid siege to Khe Sanh, official chest-beating back in Washington imbued it with great symbolic importance and there was no backing off.
Airpower kept Khe Sanh alive. The breakout of sorties on any given day, according to Momyer, included the following: tactical fighters, 350; B-52 bombers, 60; C-123 and C-130 tactical airlifters, 12 to 15; RF-4 reconnaissance, 10; and O-1 and O-2 forward air controllers, 30. AC-47 gunships kept the area illuminated at night and the enemy’s heads down. Various kinds of helicopters and other aircraft lent their support as well.
The main blow of the Tet Offensive fell on the night of Jan. 30-31, the beginning of the lunar new year. The combined forces of the North Vietnamese Army and the Viet Cong struck at population centers and military bases all over South Vietnam.
The offensive did not last long in most places, although fighting continued around Hue and Saigon. Giap did not achieve any of his military objectives. Ground forces, supported by more than 16,000 air sorties, held the line. After 77 days, Giap lifted his unsuccessful siege of Khe Sanh. Heavy casualties had broken the back of the Viet Cong irregulars, who would never again be a significant force in battle.
“By any standard of measurement,” Momyer said, “this was a major military defeat. The North Vietnamese would need almost three years to prepare for another offensive of such magnitude, and they could do it then only because of the bombing halt in North Vietnam that provided secure supply points above the DMZ.”
The effective outcome of the Tet Offensive was just the opposite. It was the turning point of the war and a great psychological defeat for the United States. Overly optimistic assessments from MACV and Washington had left the American public unprepared for the size and strength of the attacks. Support for the war was already declining in public opinion and fell further with critical news reports of the Tet Offensive, some of them erroneous.
This bad situation was made worse by a blunder by the Pentagon and MACV. In February, Army Gen. Earle G. Wheeler, Chairman of the Joint Chiefs of Staff, encouraged Westmoreland to ask for reinforcements. MACV did not need more troops to meet the Tet attacks, and Wheeler’s real agenda was to force a call-up of the National Guard and Reserve, thus replenishing military strength worldwide.
Westmoreland drew up a plan that included proposed ground operations against enemy sanctuaries in Laos, Cambodia, and on the other side of the DMZ. To cover “all contingencies,” he asked for 206,000 additional troops and raising the authorized US strength ceiling in South Vietnam to 671,616.
The proposal was discovered and reported on the front page of the New York Times March 10 under the headline, “Westmoreland Requests 206,000 More Men, Stirring Debate in Administration.” That was the end of the troop increase and the attrition strategy as well. The leak, it was discovered later, was the work of Daniel Ellsberg of RAND in a preview of his famous role in leaking the Pentagon Papers to the Times in 1971. Ellsberg had obtained a copy of a report from Wheeler to the President forwarding Westmoreland’s request. (See “The Pentagon Papers,” February, p. 50.)
Khe Sanh—which had been officially depicted in January as vitally important—was abandoned June 26 on the judgment that it was no further military value. MACV’s credibility went down another notch.
Tet marked the end of the US attempt to win the war. Lyndon Johnson’s political operatives began talking instead about “peace with honor.” In a television address to the nation March 31, Johnson announced that he would not seek re-election and that he would stop the bombing of North Vietnam in hopes of facilitating peace talks to end the war.
The Nixon Administration, which took office the following January, adopted a program of “Vietnamization,” a continuation of the withdrawal policy and the gradual turning of the war over to the South Vietnamese.
US forces in South Vietnam reached their peak strength of 549,000 in early 1969. Of those, about 450,000 were Army and Marine Corps ground forces. The drawdown began in July 1969. Ground forces left first, with airpower assuming a greater share of the burden of in-country defense.
“We were clearly on the way out of Vietnam, by negotiation if possible, by unilateral withdrawal if necessary,” Nixon’s national security advisor, Henry A. Kissinger, said later.
By the beginning of 1972, most all of the US ground forces were gone and the South Vietnamese Air Force was flying 70 percent of the air combat operations. Seventh Air Force had only half as many aircraft as before.
Meanwhile, North Vietnam’s Giap had recovered from his losses and defeat during Tet in 1968 and was ready to try again. On March 30, in the so-called Easter Offensive, he crossed the DMZ with 40,000 troops and 400 armored vehicles, once more determined to win the war with a direct conventional attack.
Halting the Offensive
The South Vietnamese F-5s and A-37s could not handle the invading force, which was strongly supported by surface-to-air missiles and anti-aircraft artillery. Interdiction required USAF F-4s and F-105s.
To add starch to the defense, the Air Force staged fighters out of its bases in Thailand to bases in South Vietnam, from which they flew their missions. The Navy and the Marine Corps increased support from carriers offshore, and SAC B-52s came from their bases in Guam and Thailand. Airpower disrupted the enemy’s supply lines and struck at the invasion forces. Giap’s 1972 offensive stalled, and in June, he pulled his forces back.
American bombing of North Vietnam, which had now resumed, did not stop until the peace agreement and cease-fire in January 1973. MACV was disestablished in March 1973. All US forces left Vietnam. South Vietnam held out until Giap mounted his third invasion two years later. Saigon fell to the advancing North Vietnamese Army on April 30, 1975. The war was finally over.
There were many instances of achievement and valor in the In-Country War, both by the ground forces and the air forces. The ground offensive, supported by airpower, achieved results that were typically good and often excellent.
These victories, however, were mostly tactical and local. They did not add up to anything of decisive strategic importance. The attrition strategy did not lead anywhere.
The big mistake was treating the war as an insurgency to be won or lost in the South. This ignored what should have been fairly obvious: The war was initiated, directed, and sustained from the North. “Although the only real pressure on the North was being applied by airpower, the ground campaign in South Vietnam remained the primary element in US strategy,” Momyer said.
We will never know whether a determined air campaign against North Vietnam might have won the war. The Johnson Administration gave up on Rolling Thunder after less than a month’s worth of timid effort. After that, operations in the North were limited and constrained lest they become too aggressive.
The ground strategy violated the principle that, in combat, one should pit one’s strength against the enemy’s weakness. The United States forfeited its unique advantage—airpower—and chose instead to conduct the war in the only venue in which the enemy could hope to compete: ground fighting in the jungle. Most of the time, the initiative lay with the enemy.
The attrition strategy was a complete miscalculation of North Vietnam’s commitment, staying power, and willingness to accept casualties if necessary to achieve victory. Westmoreland had also assumed that the United States would outlast the enemy in the attrition exchange. As it happened, US commitment wavered well before reaching the final total of 47,378 battle deaths.
By contrast, 1.1 million North Vietnamese and Viet Cong fighters were killed and 600,000 were wounded in the period 1954-75 during the long struggle first with France, South Vietnam, and the United States and its allies.
Years later, Giap said that Westmoreland had “committed an error following the Tet Offensive, when he requested another 206,000 troops. He could have put in 300,000, even 400,000 more men,” said the great Northern military man. “It would have made no difference.”