Courtesy Reuters

"Yellow Rain" and the Future of Arms Agreements

This Convention completely prohibits biological and toxin weapons. Since it provides for the elimination of existing weapons, it is a true disarmament measure."

So it seemed to Fred Charles Iklé, then director of the Arms Control and Disarmament Agency, as he testified before the Senate Foreign Relations Committee in 1974. He expressed the Ford Administration's support for ratification of a treaty with the comprehensive if awkward title, "Convention on Prohibition of the Development, Production, and Stockpiling of Bacteriological (Biological) and Toxin Weapons and Their Destruction." At the same time, he recommended that the Senate ratify the Geneva Protocol of 1925, already ratified by all the other major military powers, which prohibited the use of both biological and chemical agents in warfare.

This seemed entirely appropriate to the full blossom of détente. In November 1969, the same month U.S. and Soviet negotiators opened the Strategic Arms Limitation Talks, President Richard Nixon undertook an experiment in unilateral disarmament, unconditionally renouncing all methods of biological warfare. Three months later this renunciation was broadened to include toxin weapons, i.e., poisons produced by biological processes but not themselves living organisms. The Administration set about destroying all stockpiles of biological and toxin weapons, and closing down the research into offensive use of such weapons that had been conducted at Fort Detrick, Maryland.

This U.S. initiative was quick to bear fruit. In early 1971, the Soviet Union dropped its previous insistence that any biological weapons treaty also include chemical weapons, which had created a negotiating deadlock because the United States and Great Britain were unwilling to destroy existing chemical weapons stocks they felt served deterrent purposes. With the Soviets willing to treat biological warfare separately, the Convention was concluded a year later, and was signed by 111 nations.1

The 1972 Convention called for an end to development of biological and toxin weapons. Signatories pledged not to acquire or maintain stocks of biological agents "of types and in quantities that have no justification for prophylactic, protective or other peaceful purposes." Existing stocks and delivery equipment were to be destroyed, and transfer of either stocks or technology to third parties was specifically banned.

Perhaps curiously, the 1972 Convention did not ban the use of such weapons in warfare, though presumably this was already outlawed by the 1925 Geneva Protocol, not to mention customary international law. The Convention made only limited provision for verification of compliance with its terms. It required state parties "to consult one another and to cooperate in solving any problems which may arise." It established no supervisory machinery, but provided that governments that find evidence of violations "may lodge" complaints with the U.N. Security Council. Final appeal could be taken by persuading a majority of signatories to convene a special meeting.

In presenting the official case for ratification of the treaty, Mr. Iklé offered three arguments: that the treaty did not deny the United States any "militarily viable option" since the usefulness of such weapons was "dubious at best," that "biological weapons are particularly repugnant from a moral point of view," and that the Convention would "discourage some misguided competition in biological weapons."

Mr. Iklé added one caveat, that it would be "difficult" to verify compliance with the Convention "in countries with relatively closed societies." This did not preclude an agreement because the weapons were deemed militarily unimportant, but "the limited verifiability of this Convention should not be misconstrued as a precedent for other arms limitations agreements."

Such doubts seemed footnotes, though, compared to the promise of the Convention. As President Nixon, who had first requested ratification, had put it in his official message, it was "the first international agreement since World War II to provide for the actual elimination of an entire class of weapons from the arsenal of nations." The Convention seemed an apt expression of the spirit of détente, and a significant victory for arms control. It was ratified by the Senate, along with the Geneva Protocol, December 16, 1974. With deposit of U.S. ratification in Washington, Moscow and London, the Convention went officially into force on March 26, 1975.


Beginning in the summer of 1975, H'Mong refugees fleeing Laos for Thailand started to carry terrifying stories. They spoke of aircraft attacking their villages with rockets that exploded overhead to release a cloud of vapor, usually described as yellow or white, but sometimes red or green. As the vapors settled over the huts and fields, they caused bizarre medical symptoms. Those most exposed frequently died, and similar though milder symptoms were reported by those on the periphery of an attack or who ate food or drank water contaminated with the yellowish powder. The refugees described dizziness, severe itching or tingling of the skin, the formation of numerous small and hard blisters, nausea, shock, coughing of blood-tinged material, bloody diarrhea, and vomiting of massive amounts of blood.

The H'Mong are primitive mountain people historically at odds with the lowland Lao, and for that matter any central authority. During the Vietnam War many of them fought against the North Vietnamese and Pathet Lao in a force organized under General Vang Pao and supported by the United States. At the time they were referred to as the Meo, the Laotian term for the tribes. They now complained that the Pathet Lao and North Vietnamese were attacking their villages in retribution for helping the United States during the War. Having little grasp of modern technology, or even a written language, they christened the gruesome new weapon "yellow rain."

In 1975 and 1976, however, such reports remained fragmentary. The reported attacks took place in north-central Laos; the journey to Thailand was long and arduous. U.S. intelligence had no systematic procedures for collecting such reports, and the available information came from doctors working in the refugee camps and the volunteer efforts of two Bangkok embassy officials, Foreign Service Officer Edward McWilliams and Lieutenant Colonel C. Dennison Lane.

By 1977 and 1978, the number of reports of apparent chemical attacks began to increase alarmingly, especially from the H'Mong stronghold area in the Phou Bia mountains. In October 1978, U.S. officials raised the reports with the Lao Chargé d'Affaires in Washington, and Assistant Secretary of State Richard Holbrooke went to Vientiane to express American concern over human rights for the H'Mong. In March 1979, the United States raised the issue of poison gas use at the 35th session of the U.N. Human Rights Commission. The Laotians consistently denied the use of chemical weapons.

In May 1979, Mr. McWilliams went to refugee camps in Thailand to interview H'Mong eyewitnesses, and compiled a lengthy report of his conversations. This represented the first systematic record of the reports, and became the basis for later compilations published by the State Department. In the fall a U.S. Army medical team was dispatched to Thailand to conduct interviews. In the winter of 1979, the U.S. government raised the "yellow rain" issue with the governments of the Soviet Union, Laos and Vietnam; all three denied the charges.

By 1980 similar reports were being received from Kampuchea, where Khmer Rouge forces were still holding out against Vietnamese, and from Afghanistan, where Soviet troops were fighting against local resistance. The Carter Administration became concerned enough to compile a 131-page collection of refugee reports and newspaper accounts of chemical attacks,2 and to seek an international investigation. In December of 1980, at the urging of U.S. and Canadian delegations and over the objections of the Soviet Union, the U.N. General Assembly voted to conduct an investigation of the charges.

The material compiled by the State Department in 1980 included interviews with a defector from the Lao People's Liberation Army who said he had been directly involved in the kind of attacks described by the H'Mong. He had flown captured U.S. L-19 and T-41 aircraft dispensing toxic chemicals over H'Mong villages in the Phou Bia area. He described the directions of Vietnamese officers, and special medical precautions taken during and after the flights. He said that the missions were called "Extinct Destruction Operations," and that he had been told by his superior officer that they were intended to "wipe out the reactionary H'Mong people."

In March 1981, the State Department issued a 33-page update of its previous compilation.3 To get a flavor of the 164 pages of documents, consider the account of Mah Hear, who had lived in the H'Mong village of Long Sa in the Phu Khao Khaoi area, and who fled to Thailand with his son in February 1981. He told of a chemical attack the previous October on a cluster of four villages in which approximately 1,000 people had died after intensive vomiting and diarrhea with blood. The dead included Mah Hear's wife and daughter, and his five-year-old son Tou Houa was questioned about the attack.

State's summary of the child's testimony reads, "Tou said that his mother and sister had been poisoned by a white plane which dropped yellow-his father said 'red'-smoke. He said that many people died vomiting. He said that many animals also died. When asked what people at the local clinic did to make him better, he responded that they played with him. When asked how he got the various sores on his body which his father had attributed earlier to the gas attacks, he responded simply that he had the injuries a long time."


From the start, U.S. chemical warfare experts in the Defense Department and at the Central Intelligence Agency were puzzled by the "yellow rain" reports from Southeast Asia. The symptomology, particularly the massive hemorrhaging, did not correspond to any known chemical warfare agent. Early samples of vegetation, clothing and human tissue from attack sites and victims showed no traces of familiar chemical agents.

Even though the symptoms did not fit any known chemical agents, there was no denying the numerous and consistent reports from Southeast Asia. Analysts in the intelligence community decided by 1979 that they needed to broaden the list of potential chemical agents. Analysts from the State Department, the Defense Department, the CIA, the Defense Intelligence Agency, the National Security Agency and the Surgeon General's Office met regularly to discuss the latest evidence and to compare notes on their own research.

In 1981, breakthroughs started. In March, a CIA medical expert sent to Southeast Asia was able to conduct covert autopsies in Kampuchea of victims of a "yellow rain" attack, which had taken place only 12 to 24 hours earlier. His examination showed severe deterioration of the gut and upper small bowel, from which he deduced that a small molecular-weight toxin must be at work. Vegetation and water samples were collected from the site of the same attack for subsequent laboratory analysis.

Back in Washington, meanwhile, Dr. Sharon Watson, a research specialist in toxicology at the Department of the Army, was also pondering the symptoms reported in the "yellow rain" accounts. She noticed a striking similarity with symptoms produced by trichothecene mycotoxins, rare but especially poisonous toxins produced by a certain strain of fusarium, a common fungus found on moldy grains. The known effects of trichothecenes include nausea, vomiting, dizziness, a burning sensation of the skin, failure of muscle coordination, diarrhea with blood and internal hemorrhaging.

By far the most prominent outbreak of trichothecene poisoning in the medical literature concerned the devastation of 50 counties of the Orenburg district of the Soviet Union in the winter of 1943-44 by an epidemic of a disease then called Alimentary Toxic Aleukia (ATA). The symptoms of this disease were similar to those the H'Mong attributed to "yellow rain," except that the Orenburg peasants did not experience the exceptionally rapid hemorrhaging with massive vomiting of blood. Thirty percent of the population of the district became seriously ill, and over ten percent of the population died.

During the Orenburg epidemic, peasants had been scrounging the winter fields for unharvested wheat and millet. A.Z. Joffee, who worked in the Soviet Union during the epidemic and later emigrated to Israel, identified poisonous fusarium in the wheat samples. The poisonous forms of these molds grow best in cold climates, especially with cycles of freezing and thawing. Three decades after the epidemic, Chester Mirocha of the University of Minnesota identified T-2, a trichothecene mycotoxin, as the active agent in a sample of the wheat provided by the Soviets.4 Trichothecene poisoning is now believed to have been responsible for the Orenburg epidemic. Trichothecenes fed to animals produce symptoms similar to those at Orenburg, and are recognized in the colder regions of North America as a veterinary problem with moldy feeds. Canada has recently established tolerance levels for trichothecene residues in wheat.

While the symptoms of trichothecene poisoning reported in the medical literature do not include the spectacular hemorrhaging claimed by the H'Mong, it was easy to form speculations to explain the discrepancy. In particular, the Orenburg peasants ingested the toxins, while villagers in Laos generally inhaled the "yellow rain." Subsequently, tests by U.S. Army scientists at Fort Detrick found that inhalation of the toxins does indeed produce pulmonary and gastric hemorrhaging that is both quick and massive; this effect can also be heightened by mixing the toxin with other agents, and by dispensing it with solvents to speed absorption.

Review of the scientific literature revealed that trichothecenes had been the subject of intense Soviet scientific investigation since the 1930s. The physical and chemical properties of the toxins, especially their chemical stability, made them ideal as warfare agents; they could also easily be mass-produced. Indeed, much of the published Soviet literature on the toxins is more concerned with how to produce them in large quantities as opposed to research into prevention or antidotes. In addition, the Soviet research projects on mycotoxins were performed at institutes previously associated with other chemical and biological warfare research.5

Dr. Watson conferred with the CIA analyst upon his return to Washington; they discovered that their theories, independently arrived at, matched completely. Samples taken from the site of the attack that killed the autopsied victims were sent for laboratory analysis. The initial tests in government labs failed to detect any evidence of mycotoxins, but some of the "yellow rain" samples, along with negative and positive control samples, were sent to Dr. Mirocha for more sophisticated analysis. In August, his laboratory reported that the sample taken from the attack site tested positive for trichothecene mycotoxins. Six years after the first "yellow rain" reports, the United States had finally identified at least one of the poisons being used in Southeast Asia-an agent of a kind clearly outlawed by the 1972 Biological Weapons Convention.


It was against this backdrop that Secretary of State Alexander Haig decided to go public with the "yellow rain" charges. Secretary Haig was scheduled to speak in Berlin on "The Democratic Revolution and Its Future" on September 13, 1981.6 One of his themes was a "double standard" under which democracies were "impugned and criticized" for the slightest questionable behavior, while "a forgiving and accepting eye is turned toward adversaries." He revealed that "We now have physical evidence from Southeast Asia which has been analyzed and found to contain abnormally high levels of three potent mycotoxins-poisonous substances not indigenous to the region and which are highly toxic to man and animals." He added that the use of such weapons in warfare was prohibited by the Geneva Protocol, and that their manufacture or possession violated the Biological Weapons Convention.

The next day the State Department held a press conference in Washington to give further details of the "yellow rain" evidence. Its five-page "fact sheet" said, "Analysis of a leaf and stem sample from Kampuchea has revealed high levels of mycotoxins of the trichothecene group." It continued: "The levels detected were up to twenty times greater than any recorded natural outbreak. Since normal background levels of these toxins are essentially undetectable, the high levels found are considered to be abnormal, and it is highly unlikely that such levels could have occurred in a natural intoxication. In point of fact, these mycotoxins do not occur naturally in Southeast Asia."7

The State Department document also included circumstantial evidence of chemical warfare, noting previously published refugee testimony. It reported that the "yellow rain" symptoms matched the known effects of trichothecene poisoning, and related some details of the 1944 Orenburg epidemic. Reporters were told that no large pharmaceutical-type facility existed in Southeast Asia which could produce these toxins, although such facilities do exist in the Soviet Union. However, no attempt was made to systematically outline the history of the discoveries. Reporters were offered an opportunity to question government experts, but the names and positions of the experts were withheld.

The press reacted to these revelations with a withering skepticism. Bob Simon, CBS State Department correspondent, reported after the briefing: "It's viewed here as far from coincidental that this information is being released with such fanfare at a time when the Reagan Administration is anxious to muster support domestically and in Europe for what it perceives as an increasing Soviet threat." When the Public Broadcasting Service's "Inside Story" went back in March 1982 to reexamine this initial coverage, Mr. Simon said: "It just seemed to me like a story that was being planted, and being planted in a rather sloppy way." Don Oberdorfer of The Washington Post said: "In the course of the questioning it came out that they were hanging this thing on one leaf and stem that had been procured from Cambodia, which struck a lot of people as not very strong evidence for a charge made by the Secretary of State in a full dress State Department briefing."8

However much blame should go to State's mishandling of the briefing or excessive skepticism by the reporters, clearly little had been done to prepare the ground for such charges. The briefing had been hastily drawn together; Secretary Haig's remarks had been inserted in his speech at the last minute, under pressure of a leak to Time magazine on the mycotoxin findings. State was also concerned about seeming to be behind the news because the book Yellow Rain was about to be released; author Sterling Seagrave had started out to investigate U.S. chemical warfare capabilities and the use of the herbicide Agent Orange, but concluded the real story was that the Soviets were already using chemical warfare on a massive scale. He had picked up the name for his book from the H'Mong, and remarked at the similarity of their symptoms to those of trichothecene poisoning.9

Prior to the State Department briefing, however, the "yellow rain" reports had received scanty public attention. There had been scattered reports in the American press, and more numerous ones in Asia. The October 1980 Reader's Digest had run a report by Jane Hamilton-Merritt, a freelance journalist and Asian studies scholar who had devoted herself to studying the H'Mong. Jim Coyne, an editor of Soldier of Fortune magazine, returned from Thailand in May 1981 with a sample of yellow powder. It was ultimately delivered to Representative Jim Leach (R-Iowa), who was vainly trying to stir up some interest in possible violations of the biological weapons treaty.10 And there had been press reports of an anthrax outbreak at Sverdlovsk in the Soviet Union in April 1979, also suggesting biological weapons activity.

This was not much to prepare the press or public for charges of such magnitude. Then, too, many observers were struck by what seemed an anomaly. If the Administration really believed the Soviets were breaking existing arms control treaties, this would seem to call for major adjustments in its whole arms control policy. Yet the week after making these charges Secretary Haig met with Soviet Foreign Minister Andrei Gromyko to schedule talks on theater nuclear forces. In November, President Reagan made his National Press Club speech proposing new strategic weapons talks under the new acronym, START. The Administration was accusing the Soviets of breaking old treaties and simultaneously proposing to negotiate new ones.

The initial skepticism of the press was fed by the attitude taken by some key scientists knowledgeable about chemical warfare, notably Matthew Meselson, a Harvard University biologist, and Julian Perry Robinson of the University of Sussex's Scientific Policy Research Unit. "In such an important situation, one looks to our government for a very high standard of evidence," Dr. Meselson told The New York Times. "But in some respects, official government statements have contained demonstrable and serious scientific errors which damage our credibility and raise doubts about our case." Dr. Robinson told ABC News: "It's ludicrous in fact to base charges of quite such moment on one sample. No analytical chemist worth his salt would go along with that."

A Mennonite missionary, Frederick Swartzendruber, said in several forums that he had traveled the H'Mong communities in Laos, and had never heard of "yellow rain." Gene Lyons, a freelance journalist who had written previously on chemical warfare, wrote on the op-ed page of The New York Times that "yellow rain" might be a "CIA hoax." The urge to dismiss the gathering evidence reached absurd lengths. In a January 21, 1982 editorial opposing U.S. development of "binary" chemical weapons, the Times' editors brushed off "yellow rain" with the passing comment, "Reports that the Russians used toxic agents in Afghanistan and Indochina have not been fully confirmed. Besides, they describe small-scale use against unprotected people in remote areas."

Two major news organizations were exceptions to the general reaction. ABC News mounted its own expedition to Southeast Asia, and found its own trichothecene-contaminated sample.11 And The Wall Street Journal repeatedly returned to the story, running some 50 articles in the 18 months following the Haig speech. But despite the rather extensive, if little circulated, knowledge that preceded the Haig speech, the "not enough evidence" mentality dominated press and presumably public impressions of "yellow rain" for more than a year after the Secretary first took it public.

Throughout 1982, however, wave after wave of accumulating evidence lapped at the shores of skepticism. In late January, the State Department published an analysis of blood samples taken from "yellow rain" victims in Kampuchea, showing the presence of HT-2, a metabolite of T-2 trichothecene toxin, in the blood of two victims.12 The samples were collected by Dr. Amos Townsend, a retired Air Force physician, who began treating refugees in Thailand in 1980 and became deeply involved in the "yellow rain" issue. In March, Secretary Haig sent a 32-page report to Congress on chemical warfare in Southeast Asia and Afghanistan, providing the most complete and up-to-date information including, for the first time, intelligence reports suggesting direct Soviet involvement-the preparation of Soviet-manufactured chemical items for inspection by Soviet officers, precautions taken in receipt of Soviet crates the Vietnamese said contained "deadly toxin chemicals," and details suggesting heavy chemical contamination in the salvage operation of a ship sunk in the Black Sea en route to Vietnam in 1975.13

Also in March, Representative Stephen Solarz (D-New York) held hearings on the subject in the Subcommittee on Asian and Pacific Affairs of the House Committee on Foreign Affairs. In the course of the hearings, he remarked, "I suspect that short of being hit on the head by yellow rain, nothing would convince Mr. Swartzendruber that it was going on." The Congressman remarked to a scientific skeptic that while totally controlled experiments are not always possible in the real world, "that does not relieve us of the responsibility of trying to make judgments about whether these things are going on." At the end of the hearings, Congressman Solarz, scarcely a cold warrior, concluded, "I don't see how a reasonable person can argue with the proposition that this is going on and that things are happening here which shouldn't be happening and which are presumably prohibited by treaty."14

When the U.N. Special Session on Disarmament opened in June 1982, the U.N. investigative team on biochemical warfare had just completed its first trip to Afghan refugee camps in Pakistan. It was not scheduled to report until the General Assembly convened in the fall, but The Wall Street Journal obtained and published extracts from a 36-page verbatim transcript of the team's interviews with Afghan refugees.15 These accounts paralleled reports about "yellow rain" from Southeast Asia, and indicated that other chemical warfare agents were also being used. The Afghans, for instance, spoke of "black smoke" which caused incapacitation and unconsciousness; victims found by Soviet troops were summarily shot. The Soviets also used other gases to kill or drive out people hiding in caves or in underground canals common in Afghanistan. (In its final report on December 1, 1982, the U.N. team concluded that the allegations were not proven, but that "circumstantial evidence" suggested "the possible use of some sort of toxic chemical substance in some instances.")16

Many heads of government addressed the summer disarmament session. When President Reagan came to speak on June 17, 1982, he had not made a major public statement on "yellow rain" despite the various State Department reports. At the United Nations, he directly accused the Soviet Union and its allies of violating the Geneva Protocol and the Biological Weapons Convention, as well as customary international law. He said that the evidence was "conclusive." He added, "Evidence of non-compliance with existing arms control agreements underscores the need to approach negotiation of any new agreements with care."

In November 1982, Secretary of State George Shultz sent yet another report to Congress, saying "the world cannot be silent in the face of such human suffering and cynical disregard for international law and agreements."17 The report included the account of a Soviet soldier who defected to the Afghan resistance and described three chemical warfare agents. At its press briefing, the State Department was able to display a Soviet gas mask it reported had been taken off a dead Soviet soldier in Afghanistan and which had proved to be contaminated with trichothecenes. This was the first identification of trichothecenes from Afghanistan, as well as being a far more dramatic piece of physical evidence than a leaf and twig sample.

This time the reaction was acceptance. "The administration has proven out the Soviet pattern by a standard that reasonable people would accept."-The Washington Post, December 1, 1982. "There now appears to be sufficient evidence for the world to reach a verdict of guilty."-The St. Louis Post-Dispatch, December 3, 1982. "The evidence now accumulated-blood samples, gas masks, testimony from a Soviet defector, a Laotian pilot, and Afghan refugees-indicates that something is definitely going on, Soviet denials to the contrary."-The Christian Science Monitor, December 1, 1982. And The Boston Globe, December 3, 1982: "The Soviets appear to be on the road to convicting themselves of egregious violations of civilized norms, both the 1925 Geneva Protocol and the 1972 Biological and Toxin Weapons Convention."


If the facts of "yellow rain" have recently become accepted, its implications have barely begun to be plumbed. What does it mean that the Soviets have supplied gruesome toxin weapons for use in a perhaps-genocidal campaign against the H'Mong? What does it mean that their own troops in Afghanistan use chemical and toxin agents in what seem to be routine military operations? What does it mean that these actions are clear and callous violations of two existing arms agreements?

To take the most obvious implications first, the discovery of "yellow rain" means that Western armed forces need to get deeply serious about defending themselves against chemical and biological weapons. After the notorious gas attacks of World War I, defense planners have of course recognized a chemical threat, and biological warfare has been a staple of science fiction. But such weapons were (perhaps miraculously) never used in World War II, presumably because the combatants felt mutually deterred. Since the Geneva Protocol had been observed even in total war, it became easy to assume it would probably also be observed in future wars. Defense planners naturally gave some prudent attention to a chemical threat, but surely gave it no high priority.

By now it is abundantly clear that the Soviets are not going to be fastidious about the Geneva Protocol. It is equally clear that they do not share our assessment that biological weapons are of "dubious" military value. Obviously they find chemicals and toxins handy in counterinsurgency operations. Nor is it any consolation from a military (let alone moral) standpoint that so far the weapons have only been used "against unprotected people in remote areas"; it can hardly be assumed they would never be used against white Europeans.

Consider, for example, the extracts from a 1977 East German military manual quoted by Richard Burt, then director of the State Department's Bureau of Politico-Military Affairs, in a 1982 speech.18 The manual expounds on the use of toxins in warfare, remarking in passing that it is now possible "to produce various toxins synthetically." It describes how toxins can be aerosolized, or dispensed with aircraft spray equipment, though "they can be used primarily in microbombs which are launched from the air or in warheads of tactical rockets." It remarks, "When they are used in combat the atmosphere can be contaminated over relatively large areas. We can expect expansion depths of up to 6 kilometers before the toxin concentration drops below lethal concentration 50"-that is, the dosage that will kill half of those exposed will extend over large areas.

What is being described here actually may be what the "neutron bomb" was wrongly imagined to be-a way of killing people and capturing cities, or military installations, intact. Many of the standard Soviet missile systems, including the Frog, the Scud and the Scaleboard and their follow-ons, have not only conventional and nuclear but also chemical capabilities.19 In a 1981 report for the Institute for Foreign Policy Analysis, Amoretta M. Hoeber, now a Deputy Assistant Secretary of the Army, reports that estimates of the proportion of chemical munitions in the Soviet stockpiles range from a low of 10 to 15 percent to a high of 50 percent.20

It bears noting, too, that while we have identified the trichothecenes, we have little idea what other chemical or biological agents we may face. The Afghan reports suggest the use of a wide variety of agents. One seems to cause rapid decomposition of bodies, another apparently induces sleep and incapacitation. Western analysts have little idea what these agents might be. Nor do we understand what mixtures might be used in biological-chemical "cocktails." In congressional testimony, Dr. Watson has said that some of the refugee accounts have included reports of a heavy garlic smell, a notable sign of DMSO (Dimethylsulfoxyd), a chemical known to rapidly penetrate the skin and other body tissues.21

Another little-understood aspect of toxin warfare is the possibility of environmental contamination and long-term health effects. Since 1977, H'Mong refugees in the United States have experienced an epidemic of sudden night deaths, in which healthy young males die in their sleep of what appears to be cardiac arrhythmia.22 Because the medical histories of the dead show no special incidence of exposure to "yellow rain" attacks, investigators at the Centers for Disease Control are disinclined to accept the H'Mong belief that these deaths are associated with "yellow rain." However, there is serious scientific speculation associating trichothecenes with heart symptoms, and apparently the mycotoxins are stored in the body rather than rapidly purged. At least one prominent pathologist, Dr. Bernard Wagner of Columbia University, suggests vigorous investigation of the possibility that the deaths could be caused by long-term effects of otherwise unnoticed exposure to trichothecenes.23

We cannot assume, finally, that Soviet preparations for biological warfare are confined to toxins. The Sverdlovsk incident suggests otherwise. Soviet émigrés brought reports of an explosion in April 1979 at Military Compound 19, classified by U.S. intelligence as a site of Soviet biological weapons activity. The explosion reportedly released a cloud that caused an epidemic of anthrax in the region. The Soviets have resisted U.S. démarches for more information on the incident, saying that there was an outbreak of anthrax, but that it was caused by tainted meat. The description of such symptoms as sudden onset of disease and respiratory difficulties, however, suggests much more deadly pulmonary anthrax, caused by inhalation of the spores and previously seen almost exclusively in wool-sorting sheds. While the incident has never been fully resolved, it does suggest the possibility of large stores of living bacteriological agents.24

Western armies are grossly unprepared for these threats. The best illustration concerns fighting vehicles. After the 1973 Middle East war, U.S. defense officials had an opportunity to examine Warsaw Pact tanks and armored personnel carriers supplied to Egypt and captured by Israel. They found that these vehicles were equipped with integral seals and air filters that provide a "positive atmosphere"-that is, enough air pressure within the vehicle that any leakage is toward the outside.25 In short, by the early 1970s the Soviets were preparing their equipment to operate in a chemical environment.

It is symptomatic of the inattention that the United States has shown toward chemical and biological warfare that the M-l tank now coming off the production lines, at a price of $1.8 million per copy, is not equipped with a positive atmosphere (though this capability is now planned as a "block" improvement in 1985). In the new Bradley armored personnel carriers, troops in a chemical environment are expected to wear individual protective suits, though such suits remain in short supply. These are not isolated instances. The Hoeber report cited Pentagon studies of chemical defenses that found them "grossly inadequate." The United States lacked, it concluded, "a protective posture capable of providing for force survival-to say nothing about providing for continued operations during a war which included chemical use."26

Beyond the realm of purely defensive measures lies the problem of deterrence. What capabilities do Western armies need to deter biological and chemical attacks? Should our doctrine be deterrence in kind, and, if so, should we develop toxin weapons? If we are not to deter in kind, should we have a doctrine of responding to chemical-biological attack with nuclear weapons-perhaps under the rubric of the Soviet term "weapons of mass destruction"? Any such doctrine would represent a dangerous lowering of the nuclear threshold, and for this reason would be unlikely to pose an effective deterrent threat.

Probably the least unsatisfactory solution is to maintain a separate chemical deterrent, which could be used in retaliation for either chemical or biological attacks. This in fact is current declaratory doctrine. The U.S. deterrent consists of large stocks of nerve gases produced prior to 1969, when President Nixon renounced biological weapons and ceased production of new chemical weapons. The Pentagon has periodically proposed to develop new "binary" chemical weapons, safer to use and handle than present weapons because lethal nerve gases are not produced until two nonlethal chemicals are mixed during flight. These proposals have been rejected, most recently when Congress turned down a Reagan proposal for their development in 1982. While defensive measures may have an even higher priority for chemical-warfare funding, "yellow rain" surely adds a new salience to the chemical-biological threat, and makes it plausible to believe that a 1960s-era deterrent may need modernizing to preserve a capability that looks usable and therefore presents a credible deterrent.


In time the military problems can be addressed, but "yellow rain" raises even more fundamental questions about the future of arms agreements with the Soviet Union. For the easy use of such barbaric weapons and the cavalier disregard of existing arms agreements says much about the character of the current Soviet elites. Of course, not even the most enthusiastic American proponents of arms control are willing to rely on trusting the Soviets; even the "nuclear freeze" movement insists that a freeze be "verifiable." But, especially in the light of our experience with the Biological Weapons Convention, we have to ask what this word means.

Debates on verification of strategic arms agreements have had a certain sterile quality. American monitors discover that, say, the Soviets have started to encode data transmitted back from new missiles under test. Critics of the Soviets contend this violates the strategic arms pacts, which prohibit interference with "national technical means" of verification. This includes electronic monitoring, they contend, and the test data is essential to understanding the capabilities of their new missiles. Defenders of arms control reply that the agreements don't really quite prohibit what the Soviets are actually doing, and that anyway it's not that important. The argument revolves not around what the Soviets are doing, but around what the agreement means.

"Yellow rain" is different. By now the debate on the quality of evidence is from all appearances closed, at least in American circles. Persuading public opinion among the allies may take more time; a recent report in The Observer suggests this may require repeating all of the hesitations and mistakes that marked development of U.S. opinion.27 Perhaps there is also still room for legalistic argument, along the lines of the East German hint that the toxins may be made synthetically and are thus merely chemical weapons (whose use, of course, would still violate the Geneva protocol), or along the lines that what is happening in Afghanistan is not technically a war. But there seems little disposition to follow any such line of reasoning, and, among those who have followed the debate, there is no great argument about the facts of what is happening in Southeast Asia and Afghanistan. The reality is that we have here arms control violations that are unambiguous, militarily important and totally cynical.

The record of how these violations were detected is at best an equivocal portent for future arms agreements. The violations involved actual battlefield use of the forbidden weapons, yet were detected and publicized only after many years. Even then, their exposure required heroic efforts by a handful of individuals, many of whom-Dr. Hamilton-Merritt, Dr. Townsend, not to mention the H'Mong-have felt desperately frustrated at being ignored or disbelieved even while people were being killed in most gruesome ways. To make much difference, verification would presumably require that outlawed weapons be detected before they are actually used, and on that the "yellow rain" episode provides cool comfort.

This experience comes atop several other new difficulties for verification. Dependence on signals intelligence, for example, has been called into question by the discovery that Geoffrey Prime, a linguist at the British code-breaking center at Cheltenham, had been a Soviet spy for 14 years. He was in a position to warn the Soviets that their codes were broken, or to help them plant misinformation. His conviction warns against putting too much confidence in our ability to intercept and read Soviet communications signals.

More fundamentally, in the negotiations on strategic and intermediate missiles, the trend of technology is away from large and easily detected fixed missile sites, and toward smaller and more mobile weapons. Many weapons in this new generation will be subject to concealment in a geographically large and socially closed nation. Verification of limits on them will be less like verifying missile silos, and more like trying to detect chemical and biological violations before the weapons were actually used.

Not surprisingly, there has recently been a new burst of talk about on-site inspection of arms agreements. We still have ongoing Soviet-American talks on a chemical weapons treaty, envisioned back in 1972 as accompanying the Biological Weapons Convention. To verify any chemical treaty, U.S. negotiators recently proposed an on-site inspection plan that Under Secretary of State Lawrence Eagleburger called "tough but fair." Mr. Eagleburger added that a treaty would require "a major revision of Soviet military strategy, which accepts use of these weapons."

For their part, the Soviets have recently dropped hints that they may be willing to open some of their nuclear power reactors to inspections by the International Atomic Energy Agency, and this is being seen as a breakthrough for on-site inspection. The IAEA is intended to police the Nuclear Nonproliferation Treaty, and is not an especially happy model for the future of on-site inspection. IAEA inspections, for example, require appointments made well in advance. Albert Wohlstetter has demonstrated that a nation could comply with IAEA requirements and still be within hours of assembling a nuclear weapon.28 There is plenty of room to doubt that a few inspections on this model would suffice to give us high confidence in detecting the kind of cheating that has taken place with the Biological Weapons Convention. Final judgments will of course depend on what verification arrangements, if any, U.S. and Soviet negotiators can reach. But even on-site inspection is not a panacea.

The warning of the "yellow rain" episode is that the Soviets have the will and the cynicism to engage in determined and calculated programs of cheating on arms agreements. We must now be sure that our verification efforts take this fully into account, and it strains the imagination to come up with provisions that satisfy that need and still might be negotiable with the Soviets. Are they really going to allow us to inspect Military Compound 19 at Sverdlovsk? Will they allow us to inspect other installations where satellite photos show animal pens that for some reason must be enclosed in military-style double fences? What about light industrial buildings that could conceal cruise missiles? Basically, do we expect them to cease to be a closed society? Conceivably there are answers to these questions, but the usual rather bland talk of verification is scarcely adequate to deal with detection problems that arise when the Soviets take quite so cynical an attitude as they have with "yellow rain."

Our experience with the Biological Weapons Convention raises a second aspect of the verification problem that may prove even more acute. We have by now ascertained the facts. Indeed, despite the frustration of those involved from the beginning, in many ways the surprising thing is not how badly the various bureaucracies behaved when faced with possible violations, but how well. The Carter Administration had staked much on arms agreements with which the revelation of "yellow rain" was bound to interfere. Yet a surprising amount was done to collect evidence and even to make it public by creating a U.N. investigation. The United Nations, if you accept its considerable inherent limitations, also made its contribution to bringing the facts to light. We entered the Biological Weapons Convention knowing it to be one of the least verifiable arms proposals around, but in the end we did succeed in verifying it. The Soviets are cheating. But the problem remains, what do we do about it?

The problem "After Detection-What?" was foreseen in a brilliant 1961 article in this journal by, curiously enough, Fred Charles Iklé.29 He warned that deterrence of arms-pact violations requires not only that a potential violator must suffer the risk of detection, but also that he may lose from the victim's reaction to it. Mr. Iklé added that "Democratic governments might experience serious political difficulties in reacting effectively to a detected evasion."

The difficulties envisioned in the 1961 article read like the history of the "yellow rain" episode. The evidence of the violation may be equivocal, or based on secret intelligence. The government may feel unsure of its ability to persuade public opinion, which in turn may be unwilling to back decisive measures such as large increases in military spending. The government may feel too much publicity on the violation may interfere with other promising policies. Finally, in an alliance, allies must be persuaded, and will further have all of the same political difficulties with their domestic opinion.

This precisely describes the current stage on "yellow rain." The American government has for over a year repeatedly asserted that the Soviets are violating arms agreements. By now it has persuaded elite opinion in the United States and, almost certainly, allied governments. But it has yet to find a course of action that promises to impose significant costs on the Soviets for these violations, and thus to deter them from equally cynical violations of other present or future arms agreements.

Indeed, for many of the same reasons outlined by Mr. Iklé, the U.S. government seems deterred from any vigorous pursuit of even the most obvious opportunities to at least embarrass the Soviets in a persistent and determined way. The Biological Weapons Convention provides procedures for taking compliance issues to the U.N. Security Council. And the United States has the option of suspending its other arms negotiations with the Soviets, on the common-sense grounds that you get disputes on old contracts settled before you enter new ones.

Even the Reagan Administration, often criticized as too hawkish on arms control issues, has refrained from such measures. A noisy Security Council debate, concluding with a Soviet veto, has been judged to be too confrontational and propagandistic, too likely to interfere with efforts to keep U.S. and particularly European public opinion on the Administration's side. The Administration recognizes, of course, that to many citizens an agreement on nuclear arms seems an overriding goal, not to be postponed for whatever reason. And, of course, President Reagan has been under pressure from the nuclear-freeze movement, from Senators opposing his nominee as the head of the arms control agency, and from European allies to be more, not less, accommodating to the Soviets in the strategic and intermediate-missile talks.

Even some within the Administration who are skeptical about the chances of reaching a sound agreement with the current Soviet leadership feel bound by force of public opinion to pursue the negotiations. A Gallup Poll in September of 1982 found that 49 percent of the public felt violations of chemical treaties should not interfere with nuclear arms talks, while 36 percent of the public felt violations were reason to suspend the talks. The Gallup analysis remarked that polls have consistently shown a strong preference for "talks" with the Soviets, and "that less than half would favor continuing talks is indicative of a strong reaction to the 'yellow rain' charges."30 These percentages might change if "yellow rain" were as well publicized as the nuclear freeze.

Surely the stance that the Soviets are violating existing treaties but that we must negotiate new ones with them presents something of an incongruity, at the very least demanding a justification or explanation not yet offered by either the Administration or the more enthusiastic proponents of arms agreements. It will be interesting and instructive to see how this is resolved or justified over time. Perhaps the "yellow rain" charges will yet simply fade away as did earlier and less-documented reports of Soviet-backed chemical warfare in Yemen in the 1960s. (The Soviets do not seem to be cooperating, however, through any slackening of their biochemical assaults in Afghanistan.) Perhaps the panoply of arms talks will fail to reach agreement on substantive issues like deep cuts in missile numbers, so that the verification issue raised by "yellow rain" will never reach the forefront of negotiation. Perhaps future arms agreements will be reached, but their ratification will be dogged by the record the government has built on "yellow rain." Or perhaps the Reagan Administration will yet seize upon the "yellow rain" issue to rebut domestic and European critics of its arms control posture, protesting that the salient problem in arms negotiation is not American inflexibility but Soviet duplicity.

Arms agreements are not after all the only way of pursuing national security interests; a balance of power to deter aggression can be maintained even without treaties. But nearly all Americans would like to see the balance ratified in formal agreements; our national tendency is to seek the rule of law. While the record of disarmament agreements during the interwar period is not encouraging, and while a case can be made that recent arms agreements have sometimes been destabilizing by encouraging weapons systems like multiple warheads, it is possible to find successful arms agreements in the historical record. The Rush-Bagot agreement of 1817 and the Treaty of Washington of 1871 demilitarized the Great Lakes and the American-Canadian border, and arguably removed real or potential venom from the Canadian-American relationship. Surely all Americans would like to see our relations with the Soviet Union codified in a similar way.

Unhappily, that prospect seems to recede as the "yellow rain" episode is studied. The hopes expressed in Mr. Iklé's 1972 testimony have proved less prescient than the fears expressed in his 1961 article. Indeed, the question is what stance toward the Geneva Protocol and the Biological Weapons Convention is most likely to advance the goal of meaningful arms agreements. As of now, the Soviets have brazenly violated existing arms agreements, and have been called to account only in the most limited way. If that is the lesson they carry away from "yellow rain," it will be no service to the future prospects of arms control.

2 Reports of the Use of Chemical Weapons in Afghanistan, Laos and Kampuchea, U.S. State Department, Bureau of Public Affairs, August 1980.

3 Update to the Compendium on the Reports of the Use of Chemical Weapons, U.S. State Department, Bureau of Public Affairs, March 1981.

5 Sharon Watson, Statement before the Committee on Armed Services, U.S. Senate, 97th Cong., 2nd sess., March 15, 1982, Washington: GPO, 1982.

6 Alexander M. Haig, Jr., "The Democratic Revolution and Its Future," Current Policy No. 311, U.S. State Department, Bureau of Public Affairs, Sept. 13, 1981.

7 "Fact Sheet" on chemical warfare, released at U.S. State Department press conference in Washington, D.C., Sept. 14, 1981.

8 "Poison or Propaganda," Inside Story, Program #207, March 5, 1982, transcript WNET-TV, New York.

9 Sterling Seagrave, Yellow Rain: A Journey Through the Terror of Chemical Warfare, New York: M. Evans and Co., 1981.

10 See Yellow Rain, Hearing before the Subcommittee on Arms Control, Oceans, International Operations and Environment of the Committee on Foreign Relations, U.S. Senate, 97th Cong. 1st sess., Nov. 10, 1981, Washington: GPO, 1981.

11 "Rain of Terror." ABC News Closeup, as broadcast over ABC Television Network, Dec. 21, 1981, transcript ABC News, New York.

12 "Analysis of Blood Samples from Chemical Attack Victims Indicates Probable Trichothecene Exposure," press release, U.S. State Department, Washington, D.C., Jan. 29, 1982.

13 Chemical Warfare in Southeast Asia and Afghanistan: Report to the Congress from Secretary of State Alexander M. Haig, Jr., March 22, 1982, Special Report No. 98, U.S. State Department, Bureau of Public Affairs. Also see transcript of "On-the-Record Briefing on Chemical Warfare in Southeast Asia and Afghanistan," March 22, 1982, U.S. State Department, Bureau of Public Affairs.

14 Foreign Policy and Arms Control Implications of Chemical Weapons, Hearings before the Subcommittees on International Security and Scientific Affairs and on Asian and Pacific Affairs, Committee on Foreign Affairs, U.S. House of Representatives, 97th Cong., 2nd sess., March 30 and July 13, 1982, Washington: GPO, 1982.

15 "Chemical-Biological Warfare in Afghanistan," The Wall Street Journal, June 7, 1982.

16 Chemical and Bacteriological (Biological) Weapons: Report of the Secretary-General, United Nations, New York, Dec. 1, 1982.

17 Chemical Warfare in Southeast Asia and Afghanistan: An Update; Report from Secretary of State George P. Shultz, Special Report No. 104, Nov. 1982, U.S. State Department, Bureau of Public Affairs.

19 Harold Brown, Annual Report to the Congress, Fiscal Year 1981, Washington: GPO, 1981, p. 92.

20 Amoretta M. Hoeber, The Chemistry of Defeat: Asymmetries in U.S. and Soviet Chemical Warfare Postures, Special Report: December 1981, Cambridge, Mass.: Institute for Foreign Policy Analysis, Inc., p. 43.

22 See "Sudden, Unexpected, Nocturnal Deaths among Southeast Asian Refugees," Morbidity and Mortality Weekly Report, Centers for Disease Control, Dec. 4, 1981, Atlanta, Ga., and William Kucewicz, "Asian Refugees: Death in the Night," The Wall Street Journal, March 1, 1982.

23 Bernard M. Wagner, "A Pathologist's Analysis of Yellow Rain," The Wall Street Journal, June 17, 1982.

24 See The Sverdlovsk Incident: Soviet Compliance with the Biological Weapons Convention?, Hearing before the Subcommittee on Oversight of the Permanent Select Committee on Intelligence, U.S. House of Representatives, 96th Cong., 2nd sess., May 29, 1980, Washington: GPO, 1980; Soviet Biological Warfare Activities, Report of the Subcommittee on Oversight, Permanent Select Committee on Intelligence, U.S. House of Representatives, 96th Cong. 2nd sess., June 1980, Washington: GPO, 1980; and Leslie H. Gelb, "Keeping an Eye on Russia," The New York Times Magazine, Nov. 29, 1981.

26 Ibid., p. ix.

27 "'Yellow Rain' Evidence Fake, Scientists Say," The Observer (London), March 6, 1983.

30 "Public Perceptions of Yellow Rain: A Wall Street Journal/Gallup Survey," The Wall Street Journal, Sept. 15, 1982.



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