William A. Buckingham, Jr., Ph.D.
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Of these terms related to the Vietnam War, which one do you think would be recognized by the most people today?
- Tet Offensive
- Khe Sanh
- William Westmoreland
- Agent Orange
I wouldn't bet against Agent Orange as the winner of this poll. It has been 30 years since the last U.S. Air Force herbicide flight in Southeast Asia, yet the controversy over these missions and their aftereffects continues. The widespread use of herbicides in Southeast Asia was a unique military operation, and examining the decisions which led to the initiation, expansion, and eventual termination of these spray flights may provide insights about the larger war of which they were a part. The history of this operation may also reveal a useful pattern for anticipating the course of events that may follow the introduction of some other unconventional tool of war in a future conflict.
The term "Operation Ranch Hand" was the military code name for spraying herbicides from U.S. Air Force aircraft in Southeast Asia from 1962 through 1971.1 The name itself had no particular significance and was one of a number of similar code names such as "Farm Gate" and "Barn Door" that denoted specific military activities early in the Vietnam War. Ranch Hand aircraft were Fairchild C-123s, medium transports with twin piston engines, which later had two jet engines added for extra thrust. The Ranch Hand detachment began with six planes, dropped to two, and peaked at about 25 in 1969. It had several organizational designations over the years, but during the peak spraying years between 1966 and 1970, it was known as the 12th Air Commando Squadron and the 12th Special Operations Squadron. In terms of personnel and aircraft, Ranch Hand was a relatively minor part of overall Air Force operations in Southeast Asia.
Between 1962 and 1971, Ranch Hand sprayed about 19 million gallons of herbicide. Eleven million gallons of this total was Agent Orange.2 The spray fell mostly on the forests of South Vietnam, but some was used in Laos, and some killed crops to deprive Viet Cong and North Vietnamese troops of food. The military purpose for using herbicides on non-cropland was to remove the vegetation cover used by Viet Cong and North Vietnamese forces for concealment. Along roads, canals, railroads, and other transportation arteries, Ranch Hand cleared a swath several hundred yards wide to make ambushes more difficult. In Laos, the herbicide removed the jungle canopy from the network of roads and trails used for infiltrating men and supplies, making them more vulnerable to attack from the air. Ranch Hand also cleared large areas of forest that hid sanctuaries and bases, thereby forcing the North Vietnamese and Viet Cong to move or risk discovery and attack. In all, Ranch Hand planes sprayed herbicide over about six million acres, not correcting for multiple coverage.3
The herbicides Ranch Hand sprayed were common agricultural chemicals in wide use in the United States and other countries at that time. The most common ingredients in the herbicide mixtures were 2,4-D 4 and 2,4,5-T, phenoxy herbicides that act as growth regulators and cause destructive proliferation of tissues in plants when they are in a stage of active growth. Another plant growth regulator used was picloram. Cacodylic acid, an organic arsenic compound, killed crops by causing them to dry out.5 Various mixtures of these herbicides arrived in Vietnam in distinctive color-coded drums, the origin of the names "Agent Orange," "Agent Blue," "Agent White," etc. The primary focus in the continuing controversy over the human health effects of herbicides involves a dioxin impurity created as a byproduct in the manufacturing process of 2,4,5-T, one of the two herbicides in Agent Orange.
The Ranch Hand operation was not without historical precedent. U.S. aircraft conducted herbicide tests in World War II to see whether sprayed chemicals could be used to mark navigation points and defoliate jungle cover. An application considered but not employed in that war was destroying crops grown by isolated Japanese units on Pacific islands.6 Later, during the Malayan Emergency of the 1950s, British aircraft did spray herbicides on the isolated jungle plots of communist insurgents as part of a successful food denial program.7
In the 1950's, American military pilots in the United States worked to develop and improve herbicide delivery techniques and equipment.8 One successful experiment conducted at Camp Drum, New York, in 1959 foreshadowed what was to come later in Vietnam. Sugar maple foliage was obstructing the view of an artillery impact area, and ground access to cut down the trees was impossible because of unexploded shells. The Army Biological Warfare Laboratories sent Dr. James W. Brown, later involved in the earliest stages of the herbicide program in Vietnam, to Camp Drum. Helicopters sprayed the troublesome maple trees with a mixture of 2,4-D and 2,4,5-T, causing their leaves to dry and drop about one month later, and this greatly improved visibility.9 This experiment at Camp Drum in 1959 used the same chemicals for the same purpose for which Ranch Hand later sprayed them widely in Southeast Asia.
The Kennedy Administration inherited a deteriorating situation in Southeast Asia in 1961, and in its first months in office began to address what the United States might do to strengthen the Diem government in South Vietnam in its fight against the communist insurgency. One early approach was to investigate what "techniques and gadgets" from the reservoir of American technology might be useful in the counterinsurgency effort.10 Chemical herbicides for clearing "fire breaks" along South Vietnam's borders received specific mention as early as July 1961,11 and later that year American personnel using South Vietnamese aircraft conducted some very limited but successful tests in that country that helped to persuade President Diem to become a staunch supporter of both defoliation and crop destruction.12
A proposal to use U.S. aircraft in a more extensive defoliation and crop destruction operation received attention in Washington during the latter part of 1961. The Department of Defense favored such an operation, while at the same time recognizing the possibility of adverse international reactions. Perhaps because of this public relations risk, the Defense Department advocated initially only a selective defoliation program along key transportation routes, with the addition of crop destruction later, if at all.13 The Department of State did not object to a closely controlled and selective defoliation program and argued that such operations would not violate any rule of international law and could even be considered an accepted tactic of war, citing the Malayan precedent.14 On November 30, 1961, President John F. Kennedy personally approved in principle the start of Operation Ranch Hand,15 and for a year afterwards, all herbicide targets to be sprayed by U.S. aircraft had to receive specific Oval Office approval. It was not until late 1962 that President Kennedy delegated limited authority to order Ranch Hand defoliation missions to his ambassador and military commander in South Vietnam.16
A Vietnamese officer observes Ssgt Milo B. Coghill operate a pump aboard a C-123 during one of the early defoliation missions in Vietnam. Ssgt Coghill, along with Captain Fergus Groves, II, and Captain Robert D. Larson died in a crash during a Ranch Hand training mission on February 2, 1962, becoming the first Air Force fatalities in Vietnam. Ranch Hand planes typically sprayed at an airspeed of 130 knots only 150 feet above the ground.
The decision to begin destroying crops with herbicides was longer in coming, even though President Diem was an early and enthusiastic advocate of crop destruction. He maintained that he knew where the Viet Cong crops were,17 and South Vietnamese officials had difficulty in understanding why the Americans wouldn't give them a readily-available chemical that would accomplish with much less effort what they were already doing by cutting, pulling, and burning. Although the Defense Department favored chemical crop destruction,18 several influential people in the State Department, notably Roger Hilsman and W. Averell Harriman, were opposed. They argued that there was no way to insure that only Viet Cong crops would be killed, and the inevitable mistakes would alienate the rural South Vietnamese people. Hilsman maintained that the use of this technology would enable the Viet Cong to argue that the U.S. represented "foreign imperialist barbarism,19 and Harriman urged that crop destruction should be postponed to a later stage in the counterinsurgency struggle when the Viet Cong would not be so closely intermingled with the people.20
The pressure from Saigon continued, however, and on October 2, 1962, President Kennedy decided to allow restricted crop spraying to proceed.21 Until 1964, crop destruction operations were rare, and only South Vietnamese personnel and equipment conducted them. However, in the aftermath of the Tonkin Gulf incidents, the U.S. Ranch Hand detachment began to destroy crops. Because of the continuing sensitivity of crop destruction, Ranch Hand aircraft displayed temporary South Vietnamese markings when they flew these missions.22
Operation Ranch Hand expanded as the U.S. commitment to Vietnam deepened. Controls and limitations on spraying gradually relaxed, and new geographic areas were added. In late 1965, Ranch Hand began spraying the Ho Chi Minh Trail complex of roads and foot paths in southern and eastern Laos.23 The following year, occasional crop destruction in Laos became part of the Ranch Hand mission.24 In 1966 and 1967, Washington approved the spraying of herbicides in the Demilitarized Zone separating North and South Vietnam.25 Ranch Hand's level of operations steadily increased and peaked in 1967 when the unit sprayed 1.7 million acres, 85% for defoliation and 15% for crop destruction.26
The early use of herbicides in Southeast Asia by U.S. forces did not produce the hostile international reaction that some had feared. After the first missions in early 1962, Radio Moscow, Radio Hanoi, and Radio Peking all broadcast condemnatory reports, but the reaction from foreign non-communist capitals was light.27 The first serious public relations problem over the use of herbicides did not surface until about a year later. A reporter named Richard Dudman wrote a series of articles on U.S. policy in Asia that appeared in the St. Louis Post-Dispatch and other newspapers in February 1963. One of these articles accused the U.S. and its South Vietnamese allies of using "dirty war" tactics against the Viet Cong, including spraying "poison" from Ranch Hand planes to destroy rice fields and roadside ambush cover.28 Dudman's article so disturbed Congressman Robert W. Kastenmeier of Wisconsin that he wrote President Kennedy and urged him to renounce the use of herbicides in Vietnam, calling them chemical weapons. Kastenmeier questioned whether the survival of the Diem regime was worth compromising Americas moral principles.29 The Department of Defense responded to Kastenmeier's letter, contending that the herbicides being used in Vietnam were not chemical weapons and charging that the press and communist propaganda organs had distorted the facts about Operation Ranch Hand.30
There was another relatively serious incident of press criticism of Ranch Hand in May 1964. An article by Jim G. Lucas, a Scripps-Howard staff writer, charged that a Ranch Hand plane had accidentally sprayed the friendly village of Cha La in the Mekong Delta, destroying the rice and pineapples upon which the people depended for their livelihood.31 The Washington Post published the Lucas story and on the following day called editorially for an end to the use of herbicides in South Vietnam because they were totally unsuitable against guerrilla infiltrators living among a civilian population. Herbicides, the Post charged, were simply too unselective and non-discriminatory.32 An extensive military investigation conducted in the wake of the Cha La incident failed to substantiate the charges made by Lucas.33 At this point in the war, adverse publicity was unable to stop the expansion of Ranch Hand's activities, but these early stories and editorial comments were clear precursors of what was to follow a few years later.
The first official questioning at high levels of the wisdom of continuing chemical crop destruction seems to have been generated by a pair of RAND Corporation reports issued in October 1967. Based on interviews with a small sample of 206 former Viet Cong and non-Viet Cong civilians, RAND researchers concluded that destroying crops with herbicides had not caused any significant shortages of food among Viet Cong forces. On the other hand, RAND concluded that the spray program had generated much hostility toward the United States and its South Vietnamese allies. Crop destruction struck at the very heart of a rural South Vietnamese farmer's existence, eliminating not only the food supply upon which he and his family depended, but also obliterating in one spray pass the product of many months of his family's labor. If crop destruction had to continue, these analysts concluded, much greater efforts to lessen its impact on innocent civilians would be necessary.34
Secretary of Defense Robert S. McNamara directed the Joint Chiefs of Staff to react to RAND's criticisms.35 The Chiefs responded that spray missions against crops were meeting desired objectives, not only by causing enemy troops to go hungry in some areas but also by forcing them to divert men from combat and assign them to the tasks of procuring and transporting food. The Joint Chiefs downplayed the problem of hostility among civilians in the sprayed regions by noting that almost all crop destruction had taken place in areas uninhabited by anyone other than the Viet Cong, or in places clearly under Viet Cong domination. Presumably, anyone living there was already alienated.36 In the end, crop destruction survived this round of criticism, and Ranch Hand continued to spray fields used to grow food.
A2C Ernest C. Bohn, Jr., removes hose after pumping defoliation spray into tanks of a C-123 at Da Nang AB. Note the "pop out" insignia that could be changed from U.S. Air Force markings to South Vietnamese markings when the planes were used for crop destruction.
Criticism from the civilian scientific community was also a problem for Ranch Hand. As early as 1964, the Federation of American Scientists had expressed opposition to herbicides in Vietnam on the grounds that the United States was capitalizing on the war as an opportunity to experiment in biological and chemical warfare.37 In January 1966, Professor John Edsall of Harvard and a group of 29 Boston scientists protested crop destruction, claiming that it was barbarous and an indiscriminate attack on both combatants and noncombatants.38 About a year later, the President's Science Advisor received a petition signed by more than 5,000 scientists, including 17 Nobel laureates and 129 members of the National Academy of Sciences, urging President Johnson to stop using antipersonnel and anticrop chemicals in Vietnam. They argued that moral restraints against chemical and biological weapons were being breached, thereby weakening the barriers against more lethal chemical weapons.39
In 1967, the American Association for the Advancement of Science, prodded by Professor E.W. Pfeiffer of the University of Montana, urged the Department of Defense to study the possible long-range ecological consequences of Ranch Hand's extensive use of herbicides in Vietnam.40 The Department of Defense had commissioned the Midwest Research Institute to undertake such a study based on a survey of existing literature, and the results of this survey appeared in December 1967. Its conclusions were that the plant-killing effects of the Ranch Hand herbicides would not last long and that revegetation would occur. On the question of toxicity to animals and people, the Midwest Research Institute researchers determined that this should not be a factor of real concern, except perhaps for cacodylic acid which should be the subject of future investigations. The National Academy of Sciences panel that reviewed their report concluded that there was not yet enough research about the effects of heavy or repeated herbicide spraying to draw firm conclusions about damage to the ecology. Although Ranch Hand was not found guilty of causing permanent ecological damage by Defense sponsored research at this time, the question had been raised and began to undermine the operation's future.41
At the same time that ecological doubts and fears were developing, economic and political criticism of Ranch Hand also began to limit its future. A policy review committee appointed by Ambassador Ellsworth Bunker in Saigon in early 1968 examined the herbicide program in detail, and although Bunker's group concluded that Ranch Hand had been successful militarily, they also pointed out some associated problems. The economic costs of the operation included damage to large areas of forest, one of South Vietnam's most valuable resources and a major basis of employment. Although crop destruction had contributed to enemy logistics difficulties, Bunker's analysts concluded that the civilian population of the sprayed areas had borne the main burden. Also criticized was the system that settled civilian claims for herbicide damage. The review committee said that most damage occurred outside the areas of Saigon's control where the compensation machinery did not operate, and corrupt local officials were a problem where it did.42
In September 1968, Ambassador Bunker reported the results of his herbicide policy review to President Nguyen Van Thieu of South Vietnam. Thieu responded that herbicides had demonstrated military value earlier in the war but that their future use should be limited and highly selective. He felt that with Vietnamese and American ground forces now being stronger and more capable, herbicides should only be sprayed along infiltration routes and in uninhabited regions. It would no longer be wise, Thieu felt, to use herbicides in populated and cultivated areas because of the propaganda benefits that would accrue to his communist opponents.43 Although American military support for Ranch Hand was still strong, Thieus coolness at this time was an important negative factor.
As the Nixon Administration began in 1969 to implement its policy of reducing the American presence in Southeast Asia, Ranch Hand came under increasing pressure to cut back. In late 1969, the unit was ordered to reduce its operations by 30%,44 and it lost 11 of its 25 aircraft.45 Another complicating factor during this period was the pending vote by the U.S. Senate on the Geneva Protocol outlawing chemical and biological warfare. President Nixon favored ratification, but he maintained that the Geneva Protocol did not apply to herbicides and riot control agents. The United Nations General Assembly rejected this view in December 1969,46 and the Senate Foreign Relations Committee was reluctant to recommend ratification so long as Ranch Hand continued.47 By late 1969, the Nixon Administration had ample political reasons to want to kill Ranch Hand entirely.48
Ranch Hand's demise was made virtually certain by a study released in the fall of 1969 that presented evidence that 2,4,5- T, a component of Agent Orange, could, in relatively high doses, cause malformed offspring as well as stillbirths in mice.49 This study closely followed a spate of unsubstantiated reports in the South Vietnamese press that Agent Orange had caused human birth defects in that country. Because of doubts about the safety of 2,4,5-T, the Departments of Health, Education, and Welfare; Interior; and Agriculture on April 15, 1970, ordered the immediate banning of this chemical in the United States, except for carefully controlled use on non-cropland such as ranges and pastures.
Military authorities favored the continued spraying of Agent Orange in Southeast Asia under restrictions applicable in the United States.50 The Defense Department nevertheless "temporarily" halted all spraying of Agent Orange in April 1970, a ban that it never lifted in spite of intense and repeated protests from the military.51 With Agent Orange no longer available, Ranch Hand sprayed all existing stocks of the substitute defoliant Agent White, which did not contain 2,4,5-T, in a matter of days, flying its last defoliation mission of the war on May 9, 1970.52 Crop destruction sorties continued for a few months, but they, too, ended on January 7, 1971, putting Ranch Hand permanently out of business almost nine years to the day after it began.53
The end of the Ranch Hand flights, of course, did not terminate the controversies over what the extensive spraying of herbicides in Southeast Asia had done to the ecology of the land and the health of the people there, and of Americans who had served there. Under a congressional mandate, the Department of Defense contracted with the National Academy of Sciences in 1970 to study the effects of herbicides in Vietnam, a study that civilian scientists had long wanted.54 The National Academy of Sciences took about three years to complete its research, releasing its report to the public in 1974.55 Its researchers found no direct evidence of human health damage from herbicides, although they did uncover a pattern of largely second-hand reports, which they could not confirm, that herbicides had occasionally caused acute or fatal respiratory problems in children. Even after a considerable effort, the researchers could find no evidence substantiating a link between herbicides and human birth defects.
As was the case with humans, the National Academy of Sciences found that Ranch Hand's damage to the land and vegetation had been less than some had feared. The herbicides' main effect on trees had been to kill their leaves, and there was usually little lasting damage in future growing seasons unless the trees had been sprayed three or more times. Only about 12% of the total area covered by Ranch Hand had received triple coverage. The mangrove areas in the southern part of South Vietnam were an exception, because mangroves were killed by just one dose of spray due to their high sensitivity to herbicides. About 36% of the mangrove forest area in South Vietnam had been destroyed and would not return to its natural state for perhaps a century without extensive reseeding. Nevertheless, these researchers concluded that herbicides had not had any lasting effects on nutrients in the soil, with the possible exception of potassium. They also pointed out that the more conventional wartime bombing and shelling had a worse effect on inland forests than herbicides. Besides killing trees, shrapnel imbedded in wood made it both costly, and hazardous, to saw logs into lumber.56
Herbicide sortie over the forests of Southeast Asia.
Concern over the long-term effects on human health of exposure to herbicides lingered and reappeared. A Chicago television station aired a report on March 22, 1978, that alleged that 41 Vietnam veterans living in the Midwest were suffering from Agent Orange exposure. A Veterans Administration benefits counselor suggested this causal link because of the similarities in the backgrounds of veterans with medical problems that she had seen. The complaints of this group included diminished sex drives, psychological problems, numbness, and skin rashes.57
In the years following, the effects of herbicides on Vietnam veterans have been the subject of much scientific and political attention. Research focused in part on possible problems caused by dioxin, a byproduct produced in the manufacturing process of 2,4,5-T that had been present in the parts-per-million range in Agent Orange.58 The health of 1,200 Ranch Hand veterans who had the most extensive exposure to herbicides of any group of Americans who served in Southeast Asia has been extensively studied.59 As of 1996, the National Academy of Sciences concluded that there is positive evidence of association (but not necessarily causation) between herbicide exposure and soft-tissue sarcoma, non-Hodgkins lymphoma, Hodgkins disease, and chloracne. They have also found a limited or suggestive association between herbicides and seven other categories of disease, and further research will continue at least through 2004.60
To place events in context, the military employment of herbicides in Southeast Asia should be compared with civilian uses of the same substances. One illustrative statistic is that in the United States alone, between the years 1966 and 1969, 7,939,000 acres were treated with 2,4,5-T, the herbicide whose dioxin contaminant has caused many health concerns.61 This compares with the six million acres sprayed with all herbicides by Ranch Hand during its entire history from 1962-1971. The domestic use of 2,4,5-T was for agricultural purposes, on lawns and turf, along rights-of-way, on private forests, to kill aquatic plants, and for other purposes. There are probably few people who lived in the United States or other developed countries during the 1960s who escaped exposure to 2,4,5-T and other herbicides sprayed in Vietnam.
Honeysuckle vines were a constant problem on our woven wire fences in Tennessee. Before the general availability of herbicides, the only way to remove these vines and keep them from weighting down and destroying the fences was to laboriously hack them away. In the early 1960s, my father discovered that a simple hand sprayer and herbicide would kill honeysuckle. Some years ago I asked him what he had sprayed on the fences all those years and he directed me to a bottle in the garage. The label listed the active ingredients as an equal mixture of 2,4-D and 2,4,5-T, precisely the same as Agent Orange.62 It may be that many rural families in the United States had more cumulative exposure to "Agent Orange" than a typical U.S. soldier did in Vietnam.
The consequences of Ranch Hand's work on ecology and human health have received a great deal of attention, but anyone studying this operation must also look at the military impact of herbicides. Except for the very earliest evaluations,63 assessments of the military utility of herbicides were consistently positive. The Army's Engineer Strategic Study Group surveyed U.S. military officers who had served in Vietnam and released a report in 1972 concluding that combat operations would have been considerably more difficult without herbicides. The main military benefits had been increasing visibility from both the air and the ground and assisting in the defense of fixed bases. Crop destruction's main impact had been to force the Viet Cong and North Vietnamese to modify their operations.64 The military with few exceptions viewed Ranch Hand and the herbicides they sprayed as very valuable, and a big contributor toward saving American lives.
One approach to understanding Ranch Hand's role in the Vietnam War is to view herbicides as part of a larger American effort to bring technology to bear in the solution of a problem. Herbicides were part of a war effort that whenever possible substituted firepower and other manifestations of wealth and applied science for manpower, especially American manpower. As a substitute for herbicides, more combat troops on the ground would have denied the enemy the use of certain areas. More soldiers could have secured roads and other lines of communications against ambushes and interdiction. More numerous patrols and additional outposts to extend control in contested areas would have burdened the Viet Cong at least as much as did crop destruction. However, any of these substitutes, at least while Americans were heavily involved in ground operations, would have cost more in American lives, the most precious and politically costly resource available to U.S. military commanders and political leaders. Herbicides were an important part of the U.S. approach to the war that emphasized a remote, technological means of fighting whenever possible to reduce American casualties.
Finally, the changing nature of the times from 1962, when Ranch Hand began, to 1971, when it ended, and on to today, is a very important factor. Rachel Carson has been honored with a U.S. postage stamp, but the ecological ideas she expressed in Silent Spring in 1961 were not widespread when President Kennedy made the decisions that began and expanded the herbicide program in Vietnam. Then, the United States was in the era of "better living through chemistry." Later, it became common to question the safety and environmental impact of almost every substance, from air to rain water. This changing perception in American society of the products of technology made it much easier to perceive herbicides as dangerous and perhaps immoral. Opponents of the Vietnam War were then able to use this issue as a wedge in their broader attack on U.S. policy in Southeast Asia.
Perhaps the overall lesson to be drawn from the history of Operation Ranch Hand is that unconventional weapons and tactics can have unanticipated and unconventional effects in both the physical and political environments.