Operation Ranch Hand was a U.S. military operation during the Vietnam War, lasting from 1962 until 1971. Largely inspired by the British use of chemicals 2,4,5-T and 2,4-D (Agent Orange) during the Malayan Emergency in the 1950s, it was part of the overall herbicidal warfare program during the war called "Operation Trail Dust". Ranch Hand involved spraying an estimated 19 million U.S. gallons (72,000 m3) of defoliants and herbicides [1] over rural areas of South Vietnam in an attempt to deprive the Viet Cong of food and vegetation cover. Areas of Laos and Cambodia were also sprayed to a lesser extent. According to the Vietnamese government, the chemicals caused 400,000 deaths. [2] The United States government has described these figures as "unreliable". [3]
Nearly 20,000 sorties were flown between 1961 and 1971.[ citation needed ] The "Ranch Handers" motto was "Only you can prevent a forest" [1] – a take on the popular U.S. Forest Service poster slogan of Smokey Bear. During the ten years of spraying, over 5 million acres (20,000 km2) of forest and 500,000 acres (2,000 km2) of crops were heavily damaged or destroyed. Around 20% of the forests of South Vietnam were sprayed at least once. [4]
The herbicides were sprayed by the U.S. Air Force flying C-123s using the call sign "Hades". The planes were fitted with specially developed spray tanks with a capacity of 1,000 U.S. gallons (4 m3) of herbicides. A plane sprayed a swath of land that was 80 m (260 ft) wide and 16 km (9.9 mi) long in about 4½ minutes, at a rate of about 3 U.S. gallons per acre (3 m3/km2). [5] Sorties usually consisted of three to five aircraft flying side by side. 95% of the herbicides and defoliants used in the war were sprayed by the U.S. Air Force as part of Operation Ranch Hand. The remaining 5% were sprayed by the U.S. Chemical Corps, other military branches, and the Republic of Vietnam using hand sprayers, spray trucks, helicopters and boats, primarily around U.S. military installations. [6]
The herbicides used were sprayed at up to 50 times the concentration than for normal agricultural use.[ citation needed ] The most common herbicide used was Herbicide Orange, more commonly referred to as Agent Orange: a fifty-fifty mixture of two herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) manufactured for the U.S. Department of Defense primarily by Monsanto Corporation and Dow Chemical. The other most common color-coded Ranch Hand herbicides were Agent Blue (cacodylic acid) that was primarily used against food crops, and Agent White which was often used when Agent Orange was not available.
The Agents used are known as the Rainbow Herbicides with their active ingredients, and years used were as follows: [7]
The herbicides were procured by the U.S. military from Dow Chemical Company (all but Agent Blue), Monsanto (Agent Orange, Agent Purple, and Agent Pink), Hercules Inc. (Agent Orange and Agent Purple), Thompson-Hayward Chemical Company (Agent Orange and Agent Pink), Diamond Alkali/Shamrock Company (Agent Orange, Agent Blue, Agent Purple, and Agent Pink), United States Rubber Company (Agent Orange), Thompson Chemicals Corporation (Agent Orange and Agent Pink), Agrisect Company (Agent Orange and Agent Purple), Hoffman-Taff Inc. (Agent Orange), and the Ansul Chemical Company (Agent Blue). [8] In April 1967, the entire American domestic production of 2,4,5-T was confiscated by the military; foreign sources were also tapped into, including the Imperial Chemical Industries (ICI). [15]
65% of the herbicides used contained 2,4,5-trichlorophenoxyacetic acid that was contaminated with 2,3,7,8-tetrachlorodibenzodioxin, [6] a "known human carcinogen... by several different routes of exposure, including oral, dermal, and intraperitoneal". [16] About 12,000,000 U.S. gal (45,000,000 L; 10,000,000 imp gal) of dioxin-contaminated herbicides were sprayed over Southeast Asia (mainly in Vietnam, Cambodia, and Laos) during American combat operations in the Vietnam War. [17]
In 2005, a New Zealand government minister was quoted and widely reported as saying that Agent Orange chemicals had been supplied from New Zealand to the United States military during the conflict. Shortly after, the same minister claimed to have been mis-quoted, although this point was less widely reported. From 1962 to 1987, 2,4,5-T herbicide had been manufactured at an Ivon Watkins-Dow plant in New Plymouth for domestic use, however it has not been proven that the herbicide had been exported for use by the U.S military in Vietnam. [18] [19] [20] [21] [22]
For most of the war, Operation Ranch Hand was based at Bien Hoa Air Base (1966–1970), for operations in the Mekong Delta region where U.S. Navy patrol boats were vulnerable to attack from areas of undergrowth along the water's edge. Storage, mixing, loading, and washing areas and a parking ramp were located just off the base's inside taxiway between the Hot Cargo Ramp and the control tower. For operations along the central coast and the Ho Chi Minh trail regions, Ranch Hand operated out of Da Nang Air Base (1964–1971). Other bases of operation included Phù Cát Air Base (1968–1970), Tan Son Nhut Air Base (1962–1966), Nha Trang Air Base (1968–69), Phan Rang Air Base (1970–1972), and Tuy Hoa Air Base (1971–1972). [23] Other bases were also used as temporary staging areas for Ranch Hand. The Da Nang, Bien Hoa and Phu Cat Air bases are still heavily contaminated with dioxin from the herbicides, and have been placed on a priority list for containment and clean-up by the Vietnamese government.
The first aerial spraying of herbicides was a test run conducted on 10 August 1961 in a village north of Đắk Tô against foliage. [24] : 11 Testing continued over the next year and even though there was doubt in the State Department, the Pentagon and the White House as to the efficacy of the herbicides, Operation Ranch Hand began in early 1962. Individual spray runs had to be approved by President John F. Kennedy until November 1962, when Kennedy gave the authority to approve most spray runs to the Military Assistance Command, Vietnam and the U.S. Ambassador to South Vietnam. Ranch Hand was given final approval to spray targets in eastern Laos in December 1965. [24] : 45–68
The issue of whether or not to allow crop destruction was under great debate due to its potential of violating the Geneva Protocol. [25] However, American officials pointed out that the British had previously used 2,4,5-T and 2,4-D (virtually identical to America's use in Vietnam) on a large scale throughout the Malayan Emergency in the 1950s in order to destroy bushes, crops, and trees in effort to deny communist insurgents the cover they needed to ambush passing convoys. [26] Indeed, Secretary of State Dean Rusk told President Kennedy on 24 November 1961, that "[t]he use of defoliant does not violate any rule of international law concerning the conduct of chemical warfare and is an accepted tactic of war. Precedent has been established by the British during the emergency in Malaya in their use of aircraft for destroying crops by chemical spraying." [27] The president of South Vietnam, Ngo Dinh Diem began to push the U.S. Military Advisory Group in Vietnam and the White House to begin crop destruction in September 1961, but it was not until October 1962 when the White House gave approval for limited testing of Agent Blue against crops in an area believed to be controlled by the Viet Cong.[ citation needed ] Soon after, crop destruction became an integral part of the Ranch Hand program.
Targets for the spray runs were carefully selected to satisfy the strategic and psychological operations goals of the U.S. and South Vietnamese military. Spray runs were surveyed to pinpoint the target area and then placed on a priority list. Due to the low altitude (ideally 150 ft (46 m) required for spraying, the C-123s were escorted by fighter aircraft or helicopter gunship that would strafe or bomb the target area in order to draw out any ground fire if the area was believed to be 'hot'. Spray runs were planned to enable as straight a run as possible to limit the amount of time the planes flew at low altitude. Data on the spray runs, their targets, the herbicide used and amount used, weather conditions and other details were recorded and later put into a database called the Herbicide Reporting System (HERBS) tapes.
The effectiveness of the spraying was influenced by many factors including weather and terrain. Spray runs occurred during the early morning hours before temperatures rose above 85 °F (29 °C) and the winds picked up. Mangroves in the Delta region required only one spraying and did not survive once defoliated, whereas dense forests in the uplands required two or more spray runs. Within two to three weeks of spraying, the leaves would drop from the trees, which would remain bare until the next rainy season. In order to defoliate the lower stories of forest cover, one or more follow-up spray runs were needed. About 10 percent of the trees sprayed died from a single spray run. Multiple spraying resulted in increased mortality for the trees, as did following up the herbicide missions with napalm or bombing strikes. [28]
The use of herbicides in the Vietnam War was controversial from the beginning, particularly for crop destruction. The scientific community began to protest the use of herbicides in Vietnam as early as 1964, when the Federation of American Scientists objected to the use of defoliants. [29] The American Association for the Advancement of Science (AAAS) issued a resolution in 1966 calling for a field investigation of the herbicide program in Vietnam. [29] In 1967, seventeen Nobel laureates and 5,000 other scientists signed a petition asking for the immediate end to the use of herbicides in Vietnam. [29]
In 1970, AAAS sent a team of scientists—the Herbicide Assessment Commission (HAC), consisting of Matthew Meselson, Arthur Westing, John Constable, and Robert Cook—to conduct field tests of the ecological impacts of the herbicide program in Vietnam. [29] A 1969 study by the Bionetics Research Laboratory found that 2,4,5-T could cause birth defects and stillbirths in mice. The U.S. government suspended the military use of 2,4,5-T in the U.S. in April 1970. [29] Sporadic crop destruction sorties using Agent Blue and Agent White continued throughout 1970 until the final Ranch Hand run was flown on 7 January 1971. [29]
The use of herbicides as a defoliant had long-term destructive effects on the people of Vietnam and their land and ecology, [30] [31] as well as on those who fled in the mass exodus from 1978 to the early 1990s. According to the Vietnamese government, the US program exposed approximately 4.8 million Vietnamese people to Agent Orange, resulting in 400,000 deaths due to a range of cancers and other ailments. [2]
Hindsight corrective studies indicate that previous estimates of Agent Orange exposure were biased by government intervention and under-guessing, such that current estimates for dioxin release are almost double those previously predicted. [32] According to the Vietnamese Government, census data indicates that the United States military directly sprayed upon millions of Vietnamese during strategic Agent Orange use. [32]
According to the Vietnamese government, the program caused three million Vietnamese health problems, with 150,000 children born with severe birth defects, [33] and 24% of the area of Vietnam being defoliated. The Red Cross of Vietnam estimates that up to one million people were disabled or have health problems as a result of exposure to Agent Orange. [34] The United States government has described these figures as "unreliable". [3] According to the Department of Veteran Affairs, 2.6 million U.S. military personnel were exposed and hundreds of thousands of veterans are eligible for treatment for Agent Orange-related illnesses. [34] [35] [36]
Agent Orange is a chemical herbicide and defoliant, one of the tactical use Rainbow Herbicides.
Herbicides, also commonly known as weed killers, are substances used to control undesired plants, also known as weeds. Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides kill plants indiscriminately. The combined effects of herbicides, nitrogen fertilizer, and improved cultivars has increased yields of major crops by 3x to 6x from 1900 to 2000.
A defoliant is any herbicidal chemical sprayed or dusted on plants to cause their leaves to fall off. Defoliants are widely used for the selective removal of weeds in managing croplands and lawns. Worldwide use of defoliants, along with the development of other herbicides and pesticides, allowed for the Green Revolution, an increase in agricultural production in mid-20th century. Defoliants have also been used in warfare as a means to deprive an enemy of food crops and/or hiding cover, most notably by the United Kingdom during the Malayan Emergency and the United States in the Vietnam War. Defoliants were also used by Indonesian forces in various internal security operations.
Agent Blue is one of the "rainbow herbicides" that is known for use by the United States during the Vietnam War. It contained a mixture of dimethylarsinic acid and its related salt, sodium cacodylate, and water.
Agent Purple is the code name for a powerful herbicide and defoliant used by the U.S. military in their herbicidal warfare program during the Vietnam War. The name comes from the purple stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "Rainbow Herbicides" that included the more infamous Agent Orange. Agent Purple and Orange were also used to clear brush in Canada.
Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an area. Although herbicidal warfare use chemical substances, its main purpose is to disrupt agricultural food production and/or to destroy plants which provide cover or concealment to the enemy, not to asphyxiate or poison humans and/or destroy human-made structures. Herbicidal warfare has been forbidden by the Environmental Modification Convention since 1978, which bans "any technique for changing the composition or structure of the Earth's biota".
Agent White is the code name for a herbicide used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the regulatory requirements of identifying each container of the various herbicides through the addition of colored stripes. The colors used were orange, purple, pink, blue, and white by the manufacturers to ensure that the contents were easily identifiable during shipment and usage, as the colors were selected by the U.S. government. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "rainbow herbicides".
Agent Green is the code name for a powerful herbicide and defoliant used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the green stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "Rainbow Herbicides". Agent Green was only used between 1962 and 1964, during the early "testing" stages of the spraying program.
2,4,5-Trichlorophenoxyacetic acid, a synthetic auxin, is a chlorophenoxy acetic acid herbicide used to defoliate broad-leafed plants. It was developed in the late 1940s, synthesized by reaction of 2,4,5-Trichlorophenol and chloroacetic acid. It was widely used in the agricultural industry until being phased out, starting in the late 1970s due to toxicity concerns. Agent Orange, a defoliant used by the British in the Malayan Emergency and the U.S. in the Vietnam War, was equal parts 2,4,5-T and 2,4-D. 2,4,5-T itself is toxic with a NOAEL of 3 mg/kg/day and a LOAEL of 10 mg/kg/day. Agent Pink contained 100% 2,4,5-T. Additionally, the manufacturing process for 2,4,5-T contaminates this chemical with trace amounts of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD is a carcinogenic persistent organic pollutant with long-term effects on the environment. With proper temperature control during production of 2,4,5-T, TCDD levels can be held to about .005 ppm. Before the TCDD risk was well understood, early production facilities lacked proper temperature controls and individual batches tested later were found to have as much as 60 ppm of TCDD.
Agent Pink is the code name for a powerful herbicide and defoliant used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the pink stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the rainbow herbicides that included the more infamous Agent Orange. Agent Pink was only used during the early "testing" stages of the spraying program before 1964.
Phenoxy herbicides are two families of chemicals that have been developed as commercially important herbicides, widely used in agriculture. They share the part structure of phenoxyacetic acid.
Economic warfare or economic war is an economic strategy utilized by belligerent states with the goal of weakening the economy of other states. This is primarily achieved by the use of economic blockades. Ravaging the crops of the enemy is a classic method, used for thousands of years.
The Rainbow Herbicides are a group of tactical-use chemicals used by the United States military in Southeast Asia during the Vietnam War. Success with Project AGILE field tests in 1961 with herbicides in South Vietnam was inspired by the British use of herbicides and defoliants during the Malayan Emergency in the 1950s, which led to the formal herbicidal program Trail Dust. Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an agricultural food production area and/or to destroy dense foliage which provides the enemy with natural tactical cover.
Project Agile was an Advanced Research Projects Agency (ARPA) project in the 1960s that investigated means for engaging in remote, limited asymmetric warfare. The research was intended for use in providing U.S. support to countries engaged in fighting Communist insurgents, particularly in South Vietnam and Thailand.
2,4-Dichlorophenoxyacetic acid is an organic compound with the chemical formula Cl2C6H3OCH2CO2H. It is usually referred to by its ISO common name 2,4-D. It is a systemic herbicide that kills most broadleaf weeds by causing uncontrolled growth, but most grasses such as cereals, lawn turf, and grassland are relatively unaffected.
The Enlist Weed Control System is an agricultural system that includes seeds for genetically modified crops that are resistant to Enlist and the Enlist herbicide; spraying the herbicide will kill weeds but not the resulting crop. The system was developed by Dow AgroSciences, part of Dow Chemical Company. In October 2014 the system was registered for restricted use in Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin by the US Environmental Protection Agency. In 2013, the system was approved by Canada for the same uses.
Agent Orange is a herbicide, classified as a defoliant, that was used most notably by the U.S. military during the Vietnam War. Its primary purpose was strategic deforestation, destroying the forest cover and food resources necessary for the implementation and sustainability of the North Vietnamese style of guerilla warfare. The U.S. Agent Orange usage reached an apex during Operation Ranch Hand, in which the material was sprayed over 4.5 million acres of land in Vietnam from 1961 to 1971.
The Vietnam War had a major and long-lasting impact on the environment of the countries affected. The environment of Vietnam was severely degraded by the use of defoliants, bombing and other military activities. North Vietnam utilized the geography and ecology of the region to conceal their activities and move resources, such as via the complex network of tunnels and paths in the Ho Chi Minh trail. In response, the United States developed and deployed technologies and campaigns to clear forests and destabilize soil, greatly impacting the environment. Over time, the long-term Agricultural productivity in parts of Vietnam was reduced by many herbicidal agents and bombing campaigns. The war has also been linked to extensive deforestation and influenced the hydrology of the Mekong region.
Herbicidal warfare research conducted by the U.S. military began during the Second World War with additional research during the Korean War. Interest among military strategists waned before a budgetary increase allowed further research during the early Vietnam War. The U.S. research culminated in the U.S. military defoliation program during the Vietnam war known as Operation Ranch Hand.
Carol Van Strum is an American environmental activist who since 1975 has fought against the spraying of herbicides, including Agent Orange, in the Siuslaw National Forest in Oregon. Her subsequent research, including over 20,000 documents revealing corporate and government cover-ups, was donated to the Poison Papers project in 2017. In 2018, Van Strum received the David Brower Lifetime Achievement Award for her contributions to forestry policy favoring selective harvest without the use of herbicides.