Chemical weapons undoubtedly play an important role in international relations. An increasing number of countries are actually or allegedly acquiring these weapons, and allegations of their use continue. But the attitudes of military and political leaders are unclear. Recent events can be interpreted in very different ways.
On the one hand, some military and political leaders are questioning the military effectiveness of chemical weapons. If chemical weapons are no longer perceived to be weapons of mass destruction but, rather, to be of similar status to conventional weapons, they will lose their special deterrent value. The link between chemical and nuclear weapons will be seriously weakened.
This will have serious consequences for countries which believe that their chemical weapons deter the use of nuclear weapons against them. Some Arab countries, for example, have seen their chemical-weapon capability as balancing Israel's nuclear-weapon capability. The perception that chemical weapons do not have a status similar to that of nuclear weapons will have a destabilizing effect in, for example, the Middle East. The conclusion that only nuclear weapons deter nuclear weapons will make some countries determined to acquire nuclear weapons.
The coalition forces during the Gulf War expected the Iraqi forces to use chemical weapons against them, although in the event chemical weapons were not used. But the prospect of a chemical attack did not change the timetable of the coalition's attack. Apparently, troops in modern armies are convinced that protective clothing and gas-masks offer effective protection against chemical weapons.
The military seem to believe that, provided troops are well protected, chemical munitions are, weight for weight, less lethal than modern conventional weapons such as multiple-launch rocket systems firing rockets armed with fragmentation warheads. Moreover, the belief is growing that chemical weapons are relatively ineffective against well-protected populations provided with gas-masks and with access to
66
sealed rooms. But the great lethality of some chemical weapons, such as nerve gases, when used against unprotected populations is not doubted.
Even though there has been a change in perceptions about the utility of chemical weapons, efforts to negotiate a multilateral treaty banning the production, developing and stockpiling of these weapons continue. President Bush has, ever since coming into office, encouraged the negotiation of such a treaty, describing it as an important goal in his foreign policy.
To encourage the negotiation of a multilateral comprehensive ban on chemical weapons, the USA and the USSR negotiated a bilateral agreement, signed by President George Bush and President Mikhail Gorbachev on 1 June 1990, to reduce the huge Soviet and American chemical arsenals. Reductions will, however, be slow and will only take each stockpile down to 5,000 tonnes of chemical-warfare agents - still a considerable arsenal. And it could be the end of the year 2002 before this level is reached. But, under the bilateral agreement, the USA and Russia will cease all production of chemical weapons.
Other countries will, however, continue to produce chemical weapons, and some countries that do not now have chemical weapons plan to acquire them. Before discussing the consequences of these developments it is of interest to consider briefly the history of chemical warfare, to get some idea of the extent of the use of chemical weapons, and the nature of chemical-warfare agents.
A chemical weapon consists of a chemical agent loaded into a delivery system. The agent is a toxic chemical which attacks the biochemical processes of living organisms. Other weapons, such as incendiary weapons like phosphorus munitions, may release toxic substances but are not regarded as chemical weapons if their main effects do not rely on toxicity.
There are five main categories of chemical-warfare agent: disabling, choking, blister, blood and nerve agents. Chemical-warfare agents may be persistent, staying in the environment for days or even weeks, or non-persistent, which break down quickly.
Toxins, toxic chemicals of biological origin, are classified as both chemical- and biological-warfare agents.
Disabling, or incapacitating, agents, which include tear gases like CS and CN and arsenicals, are mainly used by police and other forces for
67
riot control. Eye effects and violent vomiting, often induced very rapidly, are the main effect of these compounds.
Chloracetophenone, or CN, is often used in civilian tear-gas weapons. A non-persistent irritant, it is used as an incapacitating agent. Chlorobenzalmalononitrile, or CS, has much stronger effects, causing vomiting, dizziness and breathing difficulties. There is a persistent form of CS which remains active for a few weeks, keeping an area free of people.
Diphenylchloroarsine, or DA, and Adamsite, or DM (10-Chloro-5, 10-dihydrophenarsazine), are arsenicals used in riot control but also early in a chemical-weapon attack. These non-persistent irritants are incapacitating agents, causing violent vomiting almost immediately after exposure. Their military utility is that vomiting prevents exposed troops from putting on gas-masks, making them vulnerable to more lethal chemical agents.
Choking agents attack the respiratory tract, making the membranes swell and the lungs fill with fluid. The victim drowns. Survivors normally suffer chronic breathing problems.
Carbonyl chloride, or phosgene, is a non-persistent, lethal choking agent. It is a colourless gas smelling of new-mown hay. Trichlorome-thyl chloroformate, or diphosgene, is another non-persistent, lethal choking agent, somewhat more stable than phosgene. The phosgenes have replaced chlorine gas, a chemical-warfare agent used extensively during the First World War. Another important non-persistent, lethal choking agent is chloropicrin (trichloronitromethane).
Blister agents produce large water blisters on exposed skin which heal slowly and may become infected. They may also damage the eyes, blood cells and respiratory tract. Most blister agents have delayed effects which may take up to four hours to emerge.
The most common blister agent is mustard gas, bis(2-chloroethyl) sulphide, also called Yperite. It is a persistent agent, which can be lethal. Mustard gas is an oily liquid, having either a garlic smell or a fishy smell.
Another blister agent is Lewisite, 2-chlorovinyldichloroarsine. A persistent blister agent, which can be lethal, Lewisite has been used in admixture with mustard gas.
68
Blood agents are absorbed into the body by breathing and kill by entering the bloodstream and, by attacking an enzyme, prevent the synthesis of molecules used by the body as an energy source. Vital organs then cease to function.
Hydrogen cyanide, also called prussic acid, and cyanogen chloride are non-persistent, lethal blood agents. They smell of bitter almonds and kill very quickly - within fifteen minutes or so.
Nerve gases are in two main groups: the G-agents and the V-agents. G-agents are non-persistent and cause death mainly by inhalation. V-agents, normally liquids, are persistent and can be absorbed through the skin. Nerve agents, which may also enter the body by oral ingestion, are extremely lethal, more potent than any other chemical-warfare agents except toxins.
Nerve gases are typically organophosphorus compounds and are tasteless and colourless. The most lethal ones are: Tabun, GA; Sarin, GB; Soman, GD; and VX. Tabun, Sarin and Soman were discovered by the Germans in the late 1930s and early 1940s. VX was first discovered in Britain.
Tabun is the compound dimethylamido-ethoxy-phosphoryl cyanide; Sarin is isopropoxymethylphosphoryl fluoride; and Soman is pinaco-loxymethylphosphoryl fluoride. Soman is much more lethal and rapid in action than Tabun and Sarin. VX is 0-ethyl S-(2-(diisopropylamino)-ethyl)methyl-phosphonothioate, and is more persistent and lethal than the G-agents. The lethal dose of the nerve agents for humans is less than 0.01 milligrams per kilogram of body weight.
Soman is semi-persistent and both respiratory and skin-penetrating. Like VX it contaminates the earth and buildings.
If you are exposed to any of the nerve gases, it will attack your nervous system. Symptoms develop more slowly when the nerve agents are absorbed through the skin than when inhaled. Soon after a significant exposure, symptoms will occur of increasingly severe damage to the nervous system. These effects occur because nerve gases (like many organophosphorus compounds) inactivate an enzyme in the body called acetylcholinesterase which is essential for the normal functioning of the nervous system.
Nerve impulses are transmitted between nerve fibres and various
69
organs and muscles by the compound acetylcholine. Normally, when acetylcholine has done its job, it is destroyed by acetylcholinesterase, so that the nerve fibres can transmit further impulses. The nerve gas inhibits acetylcholinesterase so that it cannot break down the acetylcholine. The latter accumulates and blocks the nerve function.
The symptoms will include contraction of the pupil of the eye, blurred vision, uncontrollable crying, sweating, nausea, vomiting, urinary incontinence, the accumulation of fluid in the lungs causing severe respiratory distress, loss of bladder and bowel control, and effects on the consciousness ranging from reduced mental capabilities to convulsions, deep coma and, finally, death. Death comes from suffocation, caused by paralysis of the respiratory muscles. A minute drop of a nerve gas, inhaled or absorbed through the skin or eyes, is enough to kill.
Binaries are an important development in chemical-weapon technology. A binary chemical weapon contains two chemicals. On its own, neither of them is very poisonous. But when they are mixed together they produce a nerve gas.
Isopropanol and methylphosphonyl difluoride, for example, are the two chemical components of an American binary used in 155-milli-metre artillery shells. The nerve gas produced is Sarin. The USA has also developed a binary VX spray bomb, called 'Big-eye'.
In a binary weapon, the two chemicals are kept separate until the munition is fired. When it is fired, the chemicals are mixed together, so that when the munition hits its target an aerosol cloud of nerve gas is produced. Before use, one of the chemicals is stored separately. The advantage of binary chemical weapons is that they are easier to store and safer to handle.
Chemical warfare is almost as old as warfare itself. In the fifth century BC, for example, sulphur fumes were used in Greece; and toxic smokes, based on alkaloids and toxins, were described in early Indian and Chinese literature. Arsenic and other poisonous gases were used in the Middle Ages. The Moors allegedly used aconite extracts as poisons on arrowheads against the Spaniards in 1483.
At the end of the fifteenth century, Leonardo da Vinci described the use of toxic smokes, made from a variety of poisons, during sieges and against fortifications. The smoke was typically produced in large fires so that it drifted in a large cloud over the enemy, Toxic smoke
70
warfare was conducted with artillery shells and hand grenades. But chemical warfare as we know it dates from the First World War when, for the first time, the use of chemical weapons had a significant military effect. Poison gases were used to achieve military objectives that could not be attained with other types of weapon.
During the First World War, at least forty-five chemical-warfare agents were used by both sides (the uses of chemical weapons are described in Robinson 1971). A total of about 100 million kilograms of chemicals were used, mainly chlorine, phosgene and mustard gas; they killed a total of about 100,000 people and injured another 1,200,000 or so. About 56,000 of the dead and 420,000 of the wounded were Russian. Serious after-effects, including blindness, tuberculosis, lung cancer, bronchitis and so on, afflicted the survivors, often for the rest of their lives.
Chemical weapons were used by Allied forces against Red forces during the 1919 - 21 Russian civil war. In the early 1920s, the British Royal Air Force was alleged to have used chemical weapons during peace-keeping operations in the Middle East and in the north-western frontier region of India. And in the mid-1920s the Spanish air force was said to have dropped mustard-gas bombs on Riff rebels in Morocco. Chemical weapons were allegedly used in Manchuria in the early 1930s in battles between Chinese warlords.
Chemical weapons were used by the Italians against the Ethiopians in 1935-6. About 15,000 out of a total of some 50,000 Ethiopian army casualties were caused by chemical weapons (Robinson 1971). Early in the war, Italian aircraft dropped tear-gas grenades on masses of Ethiopian troops. Soon afterwards, mustard-gas bombs were in use. For the rest of the war, mustard gas was normally sprayed from aircraft.
Japan used chemical weapons against Chinese troops and civilians between 1937 and 1945. A wide range of chemical agents were apparently used, including tear gases, phosgene, diphosgene, chloropicrin, hydrogen cyanide, mustard gas and Lewisite. The chemical weapons said to have been used included bombs, artillery shells and toxic candles. The number of Chinese casualties caused by Japanese chemical attacks is not known, but it runs into the thousands. Toxic candles producing clouds of irritant agents were used extensively by the Japanese. In one battle in July 1938, 18,000 toxic candles were lit over a 9-kilometre front to support an infantry attack.
During the Second World War, Hitler's Germany gassed several million Jews and other inmates in at least eight concentration-camps, using mainly carbon monoxide from vehicle exhausts or hydrogen cyanide. The Germans used chemical weapons on one occasion during the Polish campaign. Apparently, mustard-gas bombs were dropped
71
on the suburbs of Warsaw. And there is a report that the Germans used poison gas against Russian troops and civilians in the Crimea.
There were some unintentional releases of chemical agents. During Allied operations at Anzio in early 1943, for example, a German shell hit an Allied dump of chemical weapons and a cloud of chemical-warfare agent drifted towards the German lines.
In the Pacific war, the Japanese used hand grenades containing hydrogen cyanide against American troops on several occasions. But these were small-scale attacks, probably carried out by junior officers and soldiers without permission from the high command.
Apart from the horrific use of gas against defenceless civilian inmates in German concentration-camps, there was little military use of gas in the Second World War. Yet when the war broke out all the belligerents had chemical weapons; by the end of the war the chemical stockpiles were considerably larger than the total amounts of chemical weapons used in the First World War. Moreover, highly lethal nerve agents were available during the Second World War.
Robinson lists a number of allegations of the use of chemical weapons between 1945 and the beginning of the Vietnam War (Robinson 1971). It was alleged that both sides used chemical weapons during the 1945 - 9 Chinese civil war. In 1947 the French were accused of using gas against Vietnamese rebels, a report denied by France. In 1949, during the Greek civil war, government forces used sulphur dioxide gas, a respiratory irritant, to drive rebels out of caves.
The Americans were accused of using chemical weapons on several occasions during the 1951 - 2 Korean War. Cuban government troops were alleged to have used mustard-type chemical agents against guerrilla forces in 1957. French forces were alleged to have used poison gas against Algerian rebels in 1957. French and Spanish forces were accused by the Moroccan Saharan rebels of making a chemical attack on Rio de Oro in 1958. Also in 1958, the Chinese government accused the Chinese Nationalist forces on Quemoy of bombarding troops of the Chinese People's Army on the mainland with artillery shells containing chemical weapons.
Apart from the incident in Greece in 1949, none of the allegations of the use of chemical weapons between 1945 and 1963 has been credibly substantiated. The allegations that chemical weapons were used between 1963 and 1967 by Egyptian forces during their intervention in the civil war in the Yemen are, however, widely believed. Mustard gas and phosgene were reportedly used. According to SIPRI, casualties caused by a half of the alleged incidents 'amounted to at least 1,400 dead and about 900 severely gassed'.
In 1965 the Kurdish Democratic Party claimed that the Iraqi army used an unidentified gas against Kurdish forces - the first allegation,
72
denied by the Iraqi government, of Iraqi use of chemical weapons against the Kurds. The reported purchase of gas-masks by the Iraqi government added credibility to the Kurdish allegations.
Portuguese troops were accused of using gas against rebels in Guinea-Bissau in 1968. And Israeli forces were accused of using poison gas against Palestinian guerrillas in the Jordan valley in 1969.
A more modern form of chemical warfare is the military use of plant-killing agents (herbicides) to clear wooded areas by defoliation and to destroy food crops. Herbicides have, of course, civilian uses, particularly in agriculture and forestry. But the substances were developed from chemical-warfare research during the Second World War.
The first military use of modern anti-plant chemicals was probably their use by British forces against nationalist guerrillas in Malaya in the 1950s, The Portuguese were also accused of using anti-crop chemicals in Angola in 1970 against insurgents' food crops.
But these uses were extremely modest compared with the extensive and systematic use of anti-plant agents by the American military in Vietnam between 1961 and 1975 during what has become known as the Second Indo-China War. The massive herbicidal programme carried out by the USA over a period of more than a decade has been described by Westing (Westing 1976).
The USA sprayed a volume of more than 18 million gallons, containing almost 55 million kilograms of active herbicides, mainly on the forests of South Vietnam but also on its crops. About half a million gallons of herbicides were sprayed on Laos. Three main anti-plant agents were used, code-named Orange, White and Blue. Agent Blue killed by desiccation - by preventing a plant from retaining its moisture. Agents Orange and White killed by interfering with the normal metabolism of the sprayed plants by mimicking plant hormones. About 95 per cent of the volume of the agents was sprayed from C - 130 transport aircraft flying not far above tree-top level. Most of the rest was sprayed from helicopters.
Westing estimates that anti-plant warfare in Vietnam virtually obliterated more than 50,000 hectares of South Vietnamese inland forests. In addition, about 1.3 million hectares of upland forests (12 per cent of South Vietnam's total forest) were partially destroyed, experiencing up to 50 per cent tree mortality.
Coastal mangroves, a major source of small timbers, charcoal, fish and other products, were also attacked with anti-plant agents. About 124,000 hectares, or 41 per cent, of South Vietnam's mangrove habitat were utterly destroyed, leaving this huge area essentially lifeless.
An inadvertent consequence of this form of chemical warfare was the dissemination across South Vietnam of dioxin, an impurity of
73
Agent Orange, the most widely and heavily used of the three herbi-cides. According to Westing, a total of about 170 kilograms of dioxin was scattered over about 1 million hectares. About half of this dioxin decomposed within a few days, but the other half became incorporated into the environment, decomposing with a half-life of about 3.5 years. Because dioxin is very toxic, having carcinogenic and genetic effects on humans, there may well be long-term health effects on the indigenous population of Vietnam and on American troops involved in spraying Agent Orange.
During the second half of the 1970s there were allegations that Laotian and Vietnamese forces used mustard gas, irritants and nerve gases in aircraft attacks on rebels in Laos between 1974 and 1981. It was also alleged that mycotoxins were used in these attacks - the first time that these substances were mentioned as chemical-warfare agents, The American government also accused the Soviet forces of using mycotoxins, and nerve gas and irritants, against mujahedin forces in Afghanistan between 1979 and 1981. During the same period, Vietnamese forces were alleged to have used mycotoxins, together with nerve gas, irritants and cyanide, in Kampuchea.
The American allegation that the Soviet Union and its allies were using toxin weapons in South-East Asia and Afghanistan was serious because, if true, it would be a violation of the Biological Weapon Convention. The USA alleged that a new type of chemical toxin weapon had been developed based on mycotoxins, which are poisons produced naturally by fungi. These toxins, which are chemicals produced biologically, are said to be the agents in the 'yellow rain' reported by refugees from Laos and Kampuchea. Mycotoxins are also said to have been found on Soviet gas-masks captured in Afghanistan.
In a typical attack described, for example, by Hmong people who had lived in the Laotian Highlands, an attacking aircraft would release a cloud, often yellow in colour, that would descend on a village. Those exposed to yellow rain were said to experience, very soon after exposure, a range of symptoms, including violent itching, vomiting, dizziness and distorted vision, It was claimed that some casualties died within an hour, from shock and massive bleeding from the stomach. These symptoms are typical of those produced by some fungus poisons.
The American allegations have, however, not generally been supported by scientific evidence. An analysis, by Australian and British scientists, for example, of samples of leaves and pebbles said to be contaminated with yellow rain and collected from refugees who had fled to Thailand concluded that the samples consisted of yellow pollen grains from local rainforests. A United Nations expert group has also studied the evidence and concluded: 'While the group could not state
74
that these allegations had been proven, nevertheless it could not disregard the circumstantial evidence suggestive of the possible use of some sort of toxic chemical substance in some instances.'
An alternative explanation, supported by academic studies, is that 'yellow rain' is not a product of mycotoxin warfare but arises from mass-defecation flights by wild honey-bees (Lundin et al. 1988). Fungus spores may land on the pollen-filled faeces dropped by the bees in flight and produce natural mycotoxins. Although most experts support the view that the mycotoxins were produced naturally, the controversy has not been satisfactorily resolved.
During the 1980s, Ethiopian forces were alleged to have used chemical weapons against Eritrean secessionists and against Somali forces; Indonesian forces allegedly used chemical weapons in East Timor; Soviet-made nerve-gas weapons were reportedly used in the Angolan war against UNITA rebels; Libyan forces were accused of using poison gas in northern Chad; and, in April 1989, Soviet police used a riot-control agent - chloracetophenone (CN) - against demonstrators in Georgia, causing some deaths and injuries. But the most serious chemical-weapon attacks occurred during the Iran - Iraq War between 1983 and 1988.
Iraq used chemical weapons on frequent occasions against Iranian military forces during the war. This use was established beyond all reasonable doubt by international scientific missions sent to the war zones by the United Nations. The evidence shows that Iraq used mustard gas and nerve gas against Iranian troops on several occasions (Lundin 1989). There is evidence that Iran used mustard gas, but not nerve gas, against Iraqi forces. Iran, however, has strenuously denied the use of chemical weapons. The number of victims of chemical warfare in the Iran - Iraq War is not known, but some estimates imply that the number of casualties is in the tens of thousands, possibly many tens of thousands.
Iraq also used chemical weapons against its Kurdish civilians, most notably at Halabja in March 1988. About 5,000 Kurds died and 7,000 were injured at Halabja (Lundin 1989).
In summary, allegations of the use of chemical weapons abound. In a large fraction of the 200 or so conflicts since the Second World War, one side or the other has accused its enemy of making chemical attacks on it. But the evidence for the bulk of these allegations is flimsy indeed.
Chemical weapons were certainly used in the First World War, and by Britain and the White Army in Russia during the Russian civil war, Between the world wars, they were used by the Italians in the Ethiopia war and by Japan against China. They were probably used by the British against Afghans in 1919. During the Second World War, gas
75
was used to exterminate millions of Jews in German concentration-camps.
Since 1945 the Americans conducted extensive anti-plant warfare in South Vietnam and Laos, and Iraq used chemical weapons against Iranian forces and its own Kurdish citizens. And there are strong reasons to believe that Egypt used chemical weapons in the Yemen. Apart from these uses, other allegations must be treated with great caution.
76