June 26, 2017

A South Vietnamese UH-1H helicopter in flight over Southeast Asia in August 1971. Photos: USAF/National Archives; Oliver F. Atkins White House via National Archives

It was a strange war that Richard M. Nixon inherited when he began his presidency in 1969. His predecessor, Lyndon B. Johnson, had given up on winning, called off the air campaign against North Vietnam, and opened negotiations with the enemy.

North Vietnam, encouraged and emboldened, was not interested in a peace settlement unless all of its war aims were met—in effect, the unconditional withdrawal of US forces and surrender of the South Vietnamese government in Saigon.

To make matters worse, former members of the Johnson administration demanded that Nixon move promptly to extricate the United States from Vietnam. Nixon had no desire to continue the war. The question was how to get out of it with what he called “peace with honor.”

As Nixon’s national security advisor, Henry A. Kissinger, explained later, “America, the bulwark of free people everywhere, could not, because it was weary, simply walk away from a small ally, the commitments of a decade, 45,000 casualties, and the anguish of their families whose sacrifices would be retroactively rendered meaningless.”

The solution was seen to be “Vietnamization.” If South Vietnam could be enabled to take over the war and persuaded to do so, US forces could pull out and go home.

Credit for the “Vietnamization” term is usually given to Secretary of Defense Melvin R. Laird, who proposed it as an improvement on “de-Americanization,” suggested previously.

South Vietnamese President Nguyen Van Thieu took exception to the term because, he said, it implied that up to then, the US had done all of the fighting alone. The Pentagon kept using the word anyway on the basis that it referred only to “the assumption by the Vietnamese of that portion of the war effort carried on previously by the United States.”

The Big Switch

The Vietnamization policy was decided upon at a National Security Council meeting in March 1969. The timetable set by the White House called for the program to start in July with a completion date sometime between December 1970 and December 1972.

In the first phase, South Vietnam would take over responsibility for the ground war. Phase two would include a buildup of the South Vietnamese air force. In the final phase, US presence would be reduced to a military advisory mission.

Over the next four years, Laird would be the strongest advocate for Vietnamization. In May 1969, he informed the Joint Chiefs of Staff that Vietnamizing the war was the highest priority of the Department of Defense.

In August, Laird rewrote the mission statement for US forces in Southeast Asia. Previously, the objective had been to defeat the enemy. The new mission, as Kissinger explained it, “focused on providing ‘maximum assistance’ to the South Vietnamese to strengthen their forces, supporting pacification efforts, and reducing the flow of supplies to the enemy.”

In a speech in November, Nixon declared, “In the previous administration, we Americanized the war in Vietnam; in this administration, we are Vietnamizing the search for peace. … Under the plan, I ordered first a substantial increase in the training and equipment of South Vietnamese forces. … We have adopted a plan which we have worked out in cooperation with the South Vietnamese for the complete withdrawal of all US combat ground forces, and their replacement by South Vietnamese forces.”

The first US troop withdrawal—800 men from the 9th Infantry Division—was on July 8, 1969.

Nixon’s intention was for the mutual withdrawal of US and North Vietnamese forces, but Hanoi refused to cooperate. “The demand for mutual withdrawal grew hollow as unilateral withdrawal accelerated,” Kissinger said.

“Withdrawals would become like salted peanuts to the American public,” Kissinger added. “The more troops we withdrew, the more would be expected.

The US Drawdown

US troop strength in Vietnam peaked at 543,000 in April 1969. By the end of the year, a net reduction of about 7,000 had been achieved. Units not yet withdrawn continued to receive new arrivals as replacements for troops rotating home at the end of their one-year tours.

Nearly all of the early reductions were ground forces. Airpower was drawn down more slowly and assumed a greater share of the American involvement in the war. The level of US Air Force presence in country did not change much. In fact, the aggregate number of US aircraft in South Vietnam increased by 40 in 1969.

Ever since the Rolling Thunder air campaign against North Vietnam ended in 1968, aircraft from USAF units in South Vietnam and Thailand and from Navy carriers offshore had been available for operations in the South and for interdiction of the Ho Chi Minh Trail in Laos.

Some of the older USAF aircraft were pulled out or transferred to the Vietnamese but the principal fighter and attack platforms in South Vietnam—F-4s, F-100Ds, and A-37s—took on a stronger role than before. B-52 bombers flying from bases in Guam, Thailand, and Okinawa provided an exceptionally lethal form of close air support.

The nature of the drawdown created a unique resource problem for the Air Force. “The other services were cutting back on their SEA [Southeast Asia] commitments drastically and could devote their money and efforts to neglected future force planning,” said USAF historian Elizabeth H. Hartsook. “But Air Force commitments continued to increase.”

The Army had a different problem in the drawdown: the breakdown of morale and discipline among troops who were reluctant to engage in combat to buy time for the South Vietnamese in a war the US was no longer trying to win. The most extreme manifestation of this was “fragging” attacks on those perceived as overzealous to fight. In 1970, there were 209 instances of “fragging” with 45 killed, mostly officers and NCOs.

Laird reminded commanders that “the chief mission of our forces in South Vietnam continues to be to [ensure] the success of Vietnamization.”

The South Vietnamese Buildup

Between 1968 and 1972, the personnel strength of the Army of the Republic of Vietnam (ARVN) and the “Ruff Puffs”—the Regional Forces and Popular Forces territorial militia—increased by about 75 percent.

The United States transferred large numbers of weapons, 44,000 radio sets, and 1,800 tanks to the South Vietnamese ground forces. The Ruff Puffs were able to replace their World War II vintage M-1 Garands and Thompson submachine guns with M-16 assault rifles.

Buildup of the Vietnamese Air Force (VNAF) was more complicated. Prior to 1965, the VNAF was an all-propeller force, mainly flying T-28 and A-1 fighter-bombers and attack aircraft and C-47 transports. VNAF was a limited capability force, configured to deliver limited firepower in support of ground troops against a lightly armed enemy.

The South Vietnamese obtained jets—A-37 attack aircraft and F-5 fighters, both modifications of US Air Force trainers—between 1966 and 1968 but did not possess them in significant numbers until Vietnamization began. UH-1 Huey helicopters replaced the older H-34s. AC-47 and AC-119 gunships were added as well.

VNAF was built strictly to defend South Vietnam. It did not have the capability to strike North Vietnam on its own or to conduct interdiction missions in high-threat areas like Laos. “In the time remaining, we’re not going to create a force that will take the place of the force that’s here now,” Air Force Gen. George S. Brown, who was the deputy commander for air ops at Military Assistance Command Vietnam (MACV), said in 1970.

Thieu asked for high-performance F-4 fighters but he did not get them. Among other considerations, F-4s were “grossly beyond current VNAF maintenance capabilities,” historian Hartsook said.

VNAF coped reasonably well with the changes and in 1971, flew 63 percent of the combat air sorties in South Vietnam.

Airfields and base facilities were transferred as well. By November 1972, USAF had turned over to the South Vietnamese all installations except for Tan Son Nhut in Saigon, where 7th Air Force and MACV were headquartered.

The strength of the South Vietnamese forces peaked in 1972 at just over a million, close to the 1.1 million calculated by US planners as the limit the South Vietnamese population and economy could support.

The US dumped resources and responsibilities on the South Vietnamese faster than they could absorb them. With the possibility of a peace agreement suddenly looming in 1972, almost 700 additional airplanes—including improved model F-5E fighters—were delivered within a few months, anticipating that a cease-fire would impose restrictions on military assistance and the further provision of equipment.

“This force, although stretched by the expansion, was considered to be capable of providing close air support in an effective manner,” said USAF Gen. William W. Momyer in a postwar analysis. “It was not considered, however, that VNAF would be able to provide the highly sophisticated support that … USAF repeatedly did when there was a major engagement.”

Training and Other Issues

The rapid expansion of the South Vietnamese forces created a huge new training requirement, of which instruction for aircrews and technicians was the most difficult part.

Through 1975, VNAF continued to send several hundred officers a year to the United States for undergraduate pilot training. At the same time, South Vietnam began to develop an aircrew training program of its own. After primary training in the T-41D Mescalero at Nha Trang, fledgling airmen went to Phan Rang and the T-37 trainer for transition to F-5s and A-37s.

Training for mechanics and other technical specialists was conducted in English. This left instruction open only to those who were proficient in English, but the practice was kept for several reasons.

“The Vietnamese language, reflecting its society, had not developed words for sophisticated technology,” said journalist David Fulghum. “The language could come no closer to the M-48 tank’s ‘ballistic computer,’ for example, than to render it as an ‘adding machine.’ As late as May 1971, almost 6,000 pages of helicopter maintenance and repair manuals had yet to be translated.”

Poor maintenance was a continuing deficiency, especially on the Huey helicopters, which were the most numerous aircraft in the VNAF fleet and which required extensive service. At times in the 1970s, half of the Hueys were grounded with mechanical failures.

Yet another kind of problem was created by service politics. Thieu was an army general and the army was his power base. He effectively sidelined and isolated others, such as his rival, Air Vice Marshal Nguyen Cao Ky, and put his own people in positions of authority.

“What counted for Mr. Thieu was personal loyalty, so generals in the South Vietnamese army and provincial chiefs in the South Vietnamese government tended to be promoted on the basis of their allegiance to Mr. Thieu rather than merit,” said Fox Butterfield of The New York Times. “It was an old-fashioned, Confucian system, often greased by corruption.”

Estimates of Progress

Opinions were divided about the progress of Vietnamization. Gen. Creighton W. Abrams of MACV and Adm. John S. McCain, commander of US Pacific Command, said the program was working. Laird, returning from a visit to Saigon in 1971, said Vietnamization was “on schedule or ahead of schedule in all respects.”

Seventh Air Force historian Kenneth Sams, writing in Air Force Magazine in April 1971, reported that USAF generals regarded South Vietnamese pilots as “the elite of their nation’s armed forces” and “among the most professional flyers in the world.” Their experience was measured in years rather than months and some of them had logged as many as 4,000 combat missions.

The assessment was considerably more negative from junior officers and NCOs engaged in training the ground forces. Some ARVN units and leaders were good, but too many soldiers were deficient in everything from marksmanship to tactics and taking care of their equipment. “Vietnamization is a word for the politicians,” one major told The New York Times.

There were also reservations about the combat effectiveness of Vietnamese airmen. As shoulder-fired SAM-7 anti-aircraft missiles became more prevalent, VNAF pilots were reluctant to go below 10,000 feet to launch close air support strikes. Accuracy was not possible from such altitudes.

On balance, Hartsook said, “The South Vietnamese were not improving as fast as the US forces were withdrawing.”

Declaring Success

Further evaluation of Vietnamization was based on South Vietnamese participation in three broader military operations during the transition period: the incursions into Cambodia in 1970 and Laos in 1971, and the “Easter invasion” from North Vietnam in 1972.

In Cambodia, ARVN performed effectively alongside US ground forces in the destruction of enemy sanctuaries and supply bases. In Laos, the search-and-destroy ground operation against the Ho Chi Minh Trail was conducted by the South Vietnamese army—the use of US ground forces in Laos having been specifically forbidden by an act of Congress—supported by American airpower and logistics. Some units did well; others did not.

The more critical test came in March 1972 with a three-pronged invasion by the North Vietnamese across the Demilitarized Zone and eastward out of Laos and Cambodia.

Most of the US ground forces were already gone, so it was up to the South Vietnamese and US airpower to repel the attack. They succeeded in doing so but the key factor was clearly airpower.

“From the Easter offensive of 1972, it was apparent that the ARVN couldn’t stand up to the North Vietnamese without continuous and massive air support,” Momyer said. “ARVN was most dependent upon airpower and generally would not initiate major attacks unless airpower was assured.”

The last US Army combat troops left Vietnam in August 1972 and most of the remaining US Air Force contingent in Southeast Asia was in Thailand.

In November, seeking to persuade Thieu to support a peace agreement, Nixon gave him “absolute assurance” that “if Hanoi fails to abide by the terms of the agreement, it is my intention to take swift and severe retaliatory action.”

Operation Linebacker II, the massive air strikes on Hanoi and Haiphong in December, helped persuade the North Vietnamese to negotiate in earnest.

In congressional testimony Jan. 8, Laird said that “the Vietnamization program has been completed” and that the South Vietnamese armed forces were “fully capable” of providing security against North Vietnam within the borders of South Vietnam, making possible “the complete termination of American involvement in the war,” even if the peace talks failed.

The peace accords were signed Jan. 27, 1973, and the cease-fire went into effect Jan. 28. By June, the American military presence in South Vietnam had dwindled to a few dozen.

South Vietnam Alone

In a March 29 speech, Nixon said, “We have prevented the imposition of a Communist government on South Vietnam.” It was a bold claim, but Nixon was no longer in a position to influence events in Vietnam.

He was already engulfed by the Watergate scandal that would eventually drive him from the presidency in August 1974, and now that the United States was out of Vietnam, Congress was determined to make sure it stayed out.

In July, Congress denied funding to finance “directly or indirectly” combat operations by US forces “in or over or from the shores” of Vietnam or anywhere else in Southeast Asia. Congress also reduced assistance for South Vietnam from $2.1 billion in 1973 to $700 million in 1975.

In his memoirs, Nixon faulted Congress for withholding “the means to enforce the Paris agreement at a time when the North Vietnamese were openly violating it” and “cutting back on military aid for South Vietnam at a time when the Soviets were increasing their aid to North Vietnam.”

South Vietnam had a large army and air force but the logistics system was dismally inadequate. Aircraft and helicopters often stood idle for lack of maintenance or spare parts. After the cease-fire, there were no more replacements for aircraft lost to combat or accidents.

The effectiveness of VNAF was further diminished by the South Vietnamese style of command and control, which divided the air force up into smaller segments that were assigned to corps commanders, who were always soldiers. These army officers exercised control over all of the air and ground forces within their territory and employed them with a limited, local perspective. Without US aid, South Vietnam could not sustain or support a force of the previous size. ARVN numbers fell sharply, with high casualty and desertion rates contributing further to the decline.

The Fall of the South

The North Vietnamese began the final campaign of the war March 10, 1975, attacking with a force that included 18 army divisions—more than twice as many as they employed in the Easter invasion of 1972—as well as armor and artillery in large numbers.

North Vietnam made no effort to establish air superiority but the army was accompanied by so many radar-controlled anti-aircraft guns and SAM-7 missiles that VNAF’s slow-moving helicopters and attack aircraft were seldom able to operate in the battle areas.

ARVN, spread thin and poorly led, could not hold, so Thieu decided to abandon the highlands region and two northern provinces and make a stand farther south. The situation soon deteriorated into a disorganized rout. Hundreds of aircraft and huge stores of supplies were left behind and fell into enemy hands.

In some places, the South Vietnamese soldiers did well; elsewhere they broke and ran. “VNAF as a whole fought better than any other element of the RVNAF [Republic of Vietnam Armed Forces],” Momyer said.

Thieu resigned April 23 and flew into exile. Most of the remaining VNAF aircraft fled to Thailand on April 29 to avoid capture.

VNAF’s last combat sortie was by A-37s against North Vietnam columns moving toward the capital on April 30. Saigon fell later that day, bringing the long war in Vietnam to an end.


John T. Correll was editor in chief of Air Force Magazine for 18 years and is now a contributor. His most recent articles, “Airpower at the Bay of Pigs” and “Eisenhower and the Eight Warlords” appeared in the July issue.