Chemical and Biological Warfare

C

Recent Developments

Use of poison weapons has been alleged in only a few of the hundreds of wars and skirmishes since World War I—and has been verified in even fewer. The handful of proven cases include Italy’s limited use of chemical arms against Ethiopia in the 1930s, and Egypt’s use of chemical agents against Yemen in the 1960s. But the international agreement to avoid such weapons was most flagrantly violated by Iraq during the Iran-Iraq War. Although Iraq denied using chemical weapons, UN inspectors repeatedly found Iraqi forces were doing so. Iraq also used chemical weapons against its Kurdish citizens during the war. Experts estimate that 45,000 Iranians died as a result of Iraq's attacks, while between 3,000 and 5,000 Kurds were killed. Still, no international agency or country tried to stop Iraq’s actions. As a result, in the 1991 Persian Gulf War, which pitted Iraq against an alliance led by the United States, many nations that had been silent about Iraq’s actions faced an Iraqi army equipped with biological and chemical weapons.

In the 1991 Gulf War ground fighting lasted only a few days, and Iraq apparently did not use any chemical or biological agents. After that war, a UN resolution required Iraq to destroy its stockpiles of chemical and biological weapons, and the Iraqi government claimed that it complied with the resolution. In 1995 a Japanese cult called Aum Shinrikyo released sarin nerve agent in the Tokyo subway, killing 12 people and injuring a few thousand. Cult leaders reportedly told authorities that their choice of weapon was inspired by publicity about Iraq’s chemical arms.

III

Biological Warfare

Biological weapons are a unique class of weapons, living microorganisms. These biological agents represent a dangerous military threat because they are alive, and are therefore unpredictable and uncontrollable once released. This is one important reason that biological weapons have rarely been used.

A

Biological Agents

Biological warfare agents include bacteria, viruses, fungi, and other microorganisms that can kill or incapacitate. Since they can reproduce, biological agents have the unique potential to make an environment more dangerous over time. If used for hostile purposes, any disease-causing microorganism could be considered a weapon. For the purposes of warfare, specific characteristics of certain agents make them more likely to be used than others.

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Some potential warfare agents can make their victims very sick without necessarily killing them. Examples include the microorganisms that cause tularemia, Q fever, and yellow fever. After suffering debilitating illness, victims of these diseases often recover, although not always. Other agents are more likely to be lethal. The bacteria that cause bubonic plague and the virus that causes smallpox can kill large numbers of untreated people. Early antibiotic treatment usually cures plague victims, and smallpox vaccinations before exposure to the virus can prevent the disease.

Anthrax bacteria make effective biological weapons because of their particular features. They can exist as hardy, shell-like forms called spores, and if suspended in an aerosol can spread widely, potentially infecting thousands of people. Humans can contract anthrax spores in three ways: through a cut or opening in the skin, by inhalation, or by eating infected meat. The victims of the 2001 terrorist attack contracted cutaneous (through the skin) anthrax and inhalation anthrax. Those who died of the disease suffered from inhalation anthrax. In a warm, moist environment like the human lung, the spores can become active and lethal. Authorities believed that those who developed cutaneous anthrax handled envelopes or letters containing dry anthrax spores, and those who contracted inhalation anthrax breathed in powdery spores. Anthrax bacteria are usually found under the soil surface, and cause disease primarily in cattle and other grazing livestock. Scientists still do not know precisely how many spores are necessary to cause death, although the assumption is that inhaling 8,000 to 10,000 spores would be fatal.

Botulinum toxin is also lethal in tiny doses. Although often categorized as a biological weapon, the toxin is not itself a living agent, but a product of the bacterium Clostridium botulinum. The toxin is dangerous whether inhaled or ingested in food or drink. A gallon of botulinum toxin could poison a small city’s water system, but existing water purification systems can neutralize the toxin and protect city dwellers. See also Botulism.

B

Biological Warfare History

The use of biological weapons has been more rare than the use of chemical weapons. In the 14th century, plague-infected cadavers purportedly were catapulted into an enemy camp in the Russian Crimea. In colonial America, the British delivered blankets from their smallpox infirmary to Native Americans, hoping to infect them with the disease. In the 20th century, the only extensive military biological attacks were by Japan against China in the late 1930s and 1940s. The Japanese dropped plague and other bacteria from airplanes over several towns, causing outbreaks of disease. Until 2001, the only known terrorist use of a biological weapon in the United States occurred in 1984. Members of the Rajneesh cult in Oregon placed salmonella bacteria in the salad bars of several restaurants. At least 750 people became ill, although none died.

IV

Delivery Systems

Chemical and biological agents are most effective when dispersed into the air. These agents may be fitted into bombs or artillery shells that are designed to explode in the air and spread their contents over an enemy. In the 1980s the United States began to deploy binary chemical weapons. Before then chemical shells and bombs housed a single blistering or nerve agent. As they aged, these weapons could leak their poisons. A binary weapon is safer because it contains two relatively harmless chemicals. Only after firing do the chemicals combine to form a potent mix.

In some warfare or terrorist scenarios, an explosive release is not necessary. Members of Aum Shinrikyo attacked the Tokyo subway by packing sarin in plastic containers. To release the nerve agent, they pierced the containers with sharp umbrella tips. The leaking liquid and vapor affected thousands of passengers.

Microorganisms are generally more fragile than chemicals, and some might not survive an explosion. But several, like anthrax spores, can remain potent after an explosive release. In any case, United States Army tests have shown that biological agents can be broadly dispersed in a variety of nonexplosive ways. In the 1950s and 1960s the Army released bacteria and chemical particles in hundreds of tests in populated areas throughout the country. Agents were sprayed at San Francisco from a boat offshore, dispensed from slow-moving cars in Minneapolis and St. Louis, and released from light bulbs dropped in the New York subway. The bacteria and chemicals in the tests were not as dangerous as actual warfare agents, although they posed some risks to the exposed populations. They demonstrated that an enemy or terrorist could expose millions of people to disease-causing organisms by a variety of simple techniques.

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