chemical and biological weapons

Chemical and biological weapons cause damage to living organisms by their physiological effects rather than by direct physical impact from blast and heat. Although they can both be dispersed in the air and can inflict damage over significant areas, there are important differences between them. Chemical warfare agents are substances, whether gaseous, liquid, or solid, which might be employed because of their direct toxic effects on man, animals, or plants. Biological warfare agents are living organisms, or infective material derived from them, which are intended to cause disease or death, and which depend for their effect on their ability to multiply in the organism attacked. Toxins, though usually produced by living (biological) organisms, are classified as chemical substances because they are inanimate and cannot multiply. Biological warfare agents act much less rapidly than their chemical counterparts, but they are much more potent on a weight-for-weight basis since, under favourable environmental conditions, they can multiply after dispersal, and so smaller and less costly amounts can inflict casualties over a much wider area. On the other hand, biological warfare agents are more susceptible than chemical warfare agents to sunlight, temperature, and other environmental factors: once disseminated, a biological warfare agent can retain its viability (ability to live and multiply) while losing its virulence (ability to produce disease and injury).

Chemical and biological weapons have a long record of historical usage. Poisonous fumes were reportedly employed by the Spartans in the Peloponnesian war (429 bc) ; plague victims were thrown by Mongols into the besieged city of Caffa (now Feodosis) in the Crimea, in 1346; and blankets infected with smallpox were given by British forces to hostile Indian tribes in Ohio in 1763. Less sophisticated techniques have also been used, including the fouling of wells or other sources of drinking water with the corpses of men or animals. However, it was only in WW I that chemical science, industry, and military technology proved sufficiently developed to facilitate the large-scale and systematic use of chemical weaponry.

After some experiments with irritant agents by the French at Neuve Chapelle (27 October 1914) and the Germans at Bolimów (31 January 1915), the first major use of gas was by Germans at Ypres (22 April 1915), when 177 tons (180, 000 kg) of chlorine were released from cylinders over a front of 3.7 miles (6 km), causing panic amid the French Territorial and Algerian forces affected. Although the German forces captured a sizeable chunk of the Ypres salient, they chose to dig in at night allowing Allied forces the opportunity to regroup and launch a counter-offensive. Gas was never so effective again on the western front as both sides developed increasingly effective defences, employing respirators, alarms, anti-gas drills, some collective protection facilities, and rudimentary measures of decontamination.

In the hope of defeating such defences, the belligerents experimented with different gases and combinations of gases. These included numerous irritant and lethal agents, including phosgene (six times more poisonous than chlorine as a lung agent) ; hydrogen cyanide (a highly toxic and highly volatile blood gas) ; and mustard gas, an extremely persistent blister agent, soon known as ‘king of the war gases’ on account of its persistence, its ability to penetrate clothing, and its many-sided effects (including temporary blindness, respiratory irritation, and painful blisters). The belligerents also reduced their dependence upon unreliable cloud-gas attacks from cylinders and invested more heavily in mortars, artillery (the preferred option for all armies other than the British), and projectors (large drums filled with highly toxic chemicals, which were fired in salvoes to deliver a massive quantity of agent over a target with the maximum of surprise). Britain introduced the Livens projector at the battle of Arras/Vimy Ridge on 9 April 1917 and a German version was used with devastating effect at the battle of Caporetto. Finally, the belligerents increasingly refined their chemical tactics, with Col Georg Bruchmüller developing sophisticated counter-battery tactics and co-ordinated artillery/infantry attacks on the eastern front in 1917. Similar tactics were employed in the German spring offensive on the western front in the spring of 1918, and later, when the Germans fell back on the defensive, mustard gas was increasingly used as a defensive weapon.

Overall some 124, 000 tons of toxic agents were used during the war, causing 1.3 million casualties, or 4.6 per cent of the total number, and of these casualties, 91, 000 died. The relatively small numbers of gas casualties reflected the limited investment in chemical warfare, with chemical shells accounting for only 4.5 per cent of all shells and specialized chemical forces accounting for only 2 per cent of the total engineer strength. Gas, like other weapons, had failed to break the trench deadlock on the western front, but it had suffered from the further disadvantages of being new, unreliable particularly in its cloud-gas mode, and unavailable in sufficient quantities (even for the Germans in 1918). It was most easily assimilated as an artillery weapon and most effective against the poorly protected Russian soldiers and the inadequately trained American forces (accounting for 70, 752 US casualties or 27.4 per cent of the American total).

After the war attempts were made to proscribe the use of chemical and biological weapons, most notably in the Geneva Protocol of 1925 (see Geneva and Hague Conventions), but some countries never ratified the agreement and others reserved the right to retaliate in kind if attacked by such weapons. Nevertheless, chemical warfare recurred with the Italians employing chemical weapons against unprotected Abyssinian forces (1935-6) and the Japanese using chemical weapons in China (1937-45). The Japanese would also experiment on a small scale with biological weapons in China. Yet chemical warfare proved a rare instance of a form of warfare, developed in one war, not being used by the principal belligerents in the next war. During WW II, most powers, other than the Japanese, developed new methods of aerial delivery (using spray tanks or bombs) ; many invested in civil defence (particularly Britain) ; the Germans discovered new gases—the nearly odourless, extremely toxic, and rapid-acting nerve agents (tabun, sarin, and soman) —and the great powers accumulated vast stockpiles of chemical warfare agents (135, 000 tons in the USA alone). The non-use of gas reflected a mix of political, military, and industrial factors, including the reservations of some political leaders (especially Franklin D. Roosevelt) ; shortages of gas early in the war; intelligence misperceptions; doubts about the utility of gas in mobile warfare, amphibious landings, and in the absence of aerial superiority; the deterrent posed by threats of retaliation in kind; and the alternative, when available, of using the atomic bomb.

During the Cold War, the superpowers and some of their allies retained and developed their arsenals of chemical and biological weapons. Although new agents were discovered (notably the V agents—the most toxic form of nerve agent), biological weapons tested, and delivery systems refined (cluster bombs, rockets, and missiles), chemical and biological weapons became increasingly controversial. China and North Korea made unfounded allegations that the USA had used biological warfare during the Korean war, and domestic and international protests erupted over the American use of herbicides in the Vietnam war. While many states sought to establish new international norms against chemical and biological warfare (signing the Biological and Toxin Weapons Convention in 1972 and the Chemical Weapons Convention in 1993), the weapons were still being used and developed. There were allegations that chemical weapons and toxins were used in counter-insurgency wars in Laos, Cambodia, and Afghanistan; proven and extensive use of chemical weapons, including nerve agents for the first time, by Iraq in the Iran-Iraq war (1980-8) ; and the employment of these weapons for the purposes of killing and terrorizing civilians at Halabja (March 1988) and in Japan by the Aum Shinrikyo cult (1994-5). Coalition forces had to make extensive preparations to cope with the possibility of incurring chemical and biological attacks during the Gulf war.

By the 1980s and 1990s, several developing countries had acquired the capacity to develop, produce, and deliver chemical and biological weapons. They appreciated that these weapons, especially biological weapons, could be developed relatively cheaply (by comparison with nuclear weapons programmes) in clandestine facilities, often using materials and technology that had legitimate civilian purposes. They realized, too, that technological advances were enhancing the utility of these weapons. Binary munitions had eased the safety problems of storing and transporting chemical weapons, while the potential application of biotechnology and/or genetic engineering held the prospect of manipulating micro-organisms to make them more virulent, more stable, or more resistant to antibiotics, and thereby complicating the tasks of identifying, detecting, and protecting forces against these weapons.

Bibliography

• Dando, Malcolm, Biological Warfare in the 21st Century: Biotechnology and the Proliferation of Biological Weapons (London, 1994).
• Haber, L. F., The Poisonous Cloud: Chemical Warfare in the First World War (Oxford, 1986).
• Prentiss, Augustin M., Chemicals in War (New York, 1937).
• Spiers, Edward M., Chemical Weaponry: A Continuing Challenge (London, 1989).
• Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare, 6 vols. (Stockholm, 1971-5)

— Edward M. Spiers