By Andrew Wells-Dang
Expanded version, August 2002
In contrast to the widespread spraying of herbicides in Laos and South Vietnam over a long period, one instance of defoliation in Cambodia resulted in a major international incident. This attack took place on French- and Cambodian-owned rubber plantations in Kampong Cham province from April 18-May 2, 1969, at a time when the US had no diplomatic relations with the government of then-Prince Norodom Sihanouk. The damage caused was substantial. Both US Government and independent inspection teams confirmed that 173,000 acres were sprayed (7% of Kompong Cham province), 24,700 of them seriously affected. The rubber plantations totaled approximately one-third of Cambodia’s total and represented a loss of 12% of the country’s export earnings.
The mystery surrounding the attack has to do with who exactly carried it out. Cambodia was officially neutral in the Vietnam War, though the eastern part of its territory had been subject to infiltration by both US Special Forces (“Operation Daniel Boone”) and guerrillas on southern portions of the Ho Chi Minh Trail. No herbicides were admitted to be used, however, and large-scale US operations in Cambodia would not begin until the April 1970 covert invasion. The available evidence points to Air America, the primary air contractor for the CIA.
Once the extent of the damage in Kampong Cham became apparent, Cambodian authorities made a formal complaint to the US. It was not the first time. Cambodia had made allegations of chemical warfare against the US beginning in 1964; when any US response was given, it was always to deny that any attacks occurred. An American Quaker who was in Cambodia at the time notes, however, that the mechanism for compensating farmers for spray damage appeared to be well-established and routine, suggesting that similar incidents had happened previously. A declassified memo from the US Embassy in Saigon stating that “Past experience shows [Cambodian] protests [of chemical warfare] are not always accurate” begs the question of which protests were, in fact, true.
With no way to escape the evidence that an attack had taken place, the State Department agreed to send a team of appointed experts to investigate the damage. Memos and telegrams from the period appear confused as to what actually happened and what if any responsibility the US should take for the incident. Initial theories in Washington and the embassy in Saigon ranged from drift from spraying in neighboring Tay Ninh province, Vietnam, to an elaborate Viet Cong provocation. No one outside of the embassies appeared to believe these ideas.
The State Department inspection team of Drs. C.E. Minarik, Fred Tschirley, and two others confirmed the extent of the damage “caused by a deliberate and direct overflight of the rubber plantations.” The defoliation probably took place at a higher than normal altitude, they reported, and occurred at night. However, they could find no evidence that US planes had carried out the attack. Minarik and Tschirley were under strict orders not to divulge their findings and were also warned not to look at evidence of “alleged US-caused damage outside these terms of reference.”
An independent monitoring team followed in December 1969 led by scientists E.W. Pfeiffer and Arthur Westing. Their international delegation visited the site as well as interviewing Cambodian and foreign government officials, and concluded that the United States was responsible but that the Air Force was not involved. Although they found no concrete evidence, Pfeiffer and Westing conclude that the CIA “or some similar United States agency active in southeast Asia” carried out the attack in order to destabilize the Cambodian government, “presumably without [the] consent or even knowledge” of US embassies and the Air Force. They cited evidence of a CIA spray capability and suggest that helicopters may have been used, rather than fixed-wing aircraft. (Other sources, however, report that spraying was carried out by “Dakota” aircraft; the source of this information is unknown.)
Declassified State Department records support the CIA hypothesis. William Sullivan, promoted to undersecretary for East Asian and Pacific Affairs in Washington, confirmed in November 1969 that “the rubber plantations were not defoliated inadvertently,” but the idea that it was an enemy provocation “has some problems.” In a July 1971 letter, Sen. Frank Church of Idaho wrote, “I have been told that Air America was responsible for the Cambodian defoliation. My source was not the State Department, but rather an individual who is in a position to know the facts in this matter.” When Ambassador Ellsworth Bunker suggested responding that Senator Church’s information was “incorrect” and that “no defoliation operations were authorized in Cambodia,” he was told by his superiors in Washington to strike these sentences and insert “I had not before been advised of the allegation concerning Air America.” Additional inquiries, including several letters from Sen. Mike Gravel of Alaska, were answered with similar stonewalling responses: “Investigation has been made…not succeeded in identifying responsible party, USG neither accepted nor rejected responsibility but was processing claim...no formal determination has yet been made.”
In November 1969, the Cambodian government filed a claim of $12.2 million in damages. The US never admitted guilt, but made preparations to pay the claim amount as a way to promote “broader interests.” A lengthy State Department legal analysis concluded: “[T]here would appear to be no valid basis for rejecting the Cambodian claim for compensation…There is sufficient circumstantial and other corroborating evidence to attribute responsibility to the Government of the United States for the direct defoliation…caused by activities of United States government forces or agents. The United States Government is legally liable…”
Then-National Security Advisor Henry Kissinger attempted, however, to put off payment until fiscal year 1972, writing that “Every effort should be made to avoid the necessity for a special budgetary request to provide funds to pay this claim.” In other words, Kissinger wished to keep the payment secret. Or perhaps he already was making plans for the coup against Sihanouk and covert US-South Vietnamese invasion of Cambodia that began the following year. In any case, the Krek and Mimot areas were devastated by US bombing in the early weeks of the war, rendering any further investigation of herbicide damage or compensation irrelevant. If the State Department accepted US liability for the Kampong Cham incident, however, then this liability extends to other cases as well, whether the spraying was carried out by the CIA and Air America or other agents. That admission of liability comes with no time limitations attached.
1 Telegram from US Embassy Saigon to Sec of State, Subject: Alleged Defoliation in Cambodia, July 12, 1969; Cover letter to Report on Defoliation in Cambodia from US Ambassador to South Vietnam Bunker, July 16, 1969 (both declassified).
2 G. Deconinck and F. Ninane, “Report on a Visit to the Krek-Mimot Region After It Was Damaged by Chemical Defoliants” (in French with translation), Rubber Research Institute of Cambodia, May 6, 1969. Telegram from Secretary of State to US Embassy Saigon, May 24, 1969 (declassified).
 On Operation Daniel Boone, see: Memorandum from the Assistant Secretary of Defense for International Security Affairs (Paul Warnke) to Secretary of Defense McNamara, October 5, 1967, in Foreign Relations of the United States 1964-8, vol. XXVII, Mainland Southeast Asia (Washington: State Department, 2000), pp. 464-5; Action Memorandum from Assistant Secretary of State for East Asian and Pacific Affairs Bundy to Under Secretary of State Katzenbach, December 12, 1968, in FRUS, vol. XXVII, pp. 562-3.
 Cambodian Protest on Alleged Defoliation Damage (in French), May 19, 1969, in declassified telegram from Secretary of State to US Embassy Saigon, May 24, 1969.
 See, for instance: Telegram from US Embassy, Phnom Penh, “Transmission French text of [Cambodian] Foreign Minister [Huot Sambath] letter to Secretary of State [Dean] Rusk Accusing United States of Chemical Warfare,” August 4, 1964 (unclassified); Letter from Huot Sambath to UN Security Council, September 8, 1964; Telegrams from State Dept to Embassy in Phnom Penh re Cambodian claims of dropping “yellow powder,” February 1 and February 3, 1965; Telegram from US Embassy Saigon denying claim, February 6, 1965; Telegrams from US Embassy Phnom Penh to State Dept, subject: New Complaint of Defoliation Damage, February 2 and 10, 1970; Telegram from State Dept to US Embassy Saigon, subject: Cambodian Border Incidents, February 14, 1970; Telegram from US Embassy Saigon to Secretary of State, subject: Cambodian Complaint of Herbicide Damage, February 23, 1970 (all above declassified).
 Personal communication from Joe and Dave Elder, American Friends Service Committee, August 7, 2002.
 Telegram from US Embassy Saigon to Secretary of State, subject: Cambodian Complaint of Herbicide Damage, February 23, 1970 (declassified).
 Telegram from US Embassy, Saigon, Subject: alleged Defoliation of Cambodian Plantations, May 26, 1969; Cables from Dept of State to Australian Embassy, Phnom Penh, May 30 and June 3, 1969; Letter from Minister-Counselor for Political Affairs Martin Herz, Saigon, to Deputy Assistant Secretary of State for East Asian and Pacific Affairs William Sullivan, October 31, 1969 (all declassified).
 Statement of Thomas Pickering, Department of State, to the House Foreign Affairs Subcommittee on National Security Policy and Scientific Developments hearing on “Chemical-Biological Warfare: US Policies and International Effects,” December 18, 1969, p. 198.
 Letter to Dr. C.E. Minarik from Assistant Secretary of State Marshall Green, June 23, 1969 (declassified).
 A.H.Westing, E.W. Pfeiffer, J. Lavorel, and L. Matarasso, “Report on Herbicidal Damage by the United States in Southern Cambodia,” December 31, 1969, in Thomas Whiteside, Defoliation (Ballantine/Friends of the Earth, 1970), pp. 117-32; Whiteside, Defoliation, pp. 14-6.
 Arthur H. Westing, “Herbicidal Damage to Cambodia,” in Neilands et. al., Harvest of Death: Chemical Warfare in Vietnam and Cambodia (New York: The Free Press, 1972), pp. 177-205. Westing’s allegations are repeated in a letter to Ambassador Ellsworth Bunker, cited in a telegram from US Embassy Saigon to Dept of State, subject: Cambodian Herbicide Operation, September 7, 1971 (declassified).
 American Friends Service Committee, “Report on Defoliation in Cambodia,” May 29, 1969, p. 3; Personal communication from Joe and Dave Elder, August 7, 2002.
 Letter from Deputy Assistant Secretary of State Sullivan to Martin Herz, US Embassy Saigon, November 13, 1969 (declassified).
 Telegram from US Embassy Saigon to Dept of State, subject: Cambodian Herbicide Operation, September 7, 1971; telegram from Dept of State to US Embassy Saigon, September 18, 1971 (both declassified).
 Telegram from US Embassy Phnom Penh to Dept of State, September 8, 1971 (declassified); Letter from Assistant Secretary of State for Congressional Relations David Abshire to Sen. Mike Gravel, November 17, 1972.
 Letter from Sullivan to Herz, November 13, 1969.
 Memorandum from State Department legal advisor George H. Aldrich, subject: Defoliation of Rubber Plantations and Other Agricultural Property in Cambodia, April 6, 1973 (declassified), p. 9.
 Henry Kissinger, Memorandum for the Director of the Budget, subject: Cambodian Defoliation Claim, December 8, 1969 (declassified).
 William Shawcross, Sideshow (New York: Simon & Schuster, 1979), pp. 150-1.