The use of synthetic poisonous substances, or organisms such as disease germs, to kill or injure the enemy. They include chlorine, phosgene, and mustard gas (first used in World War I), various nerve gases, defoliant agents, and viruses and bacteria (for example, anthrax). The use of chemical and biological weapons is prohibited by the Geneva Convention, but their production, possession, or transfer are not. Unlike their World War I counterparts, modern chemical weapons are sophisticated and may be delivered by long-range artillery, missile, or sprayed from aircraft. To be effective, the chemicals must be inhaled or come into contact with skin. The main defence against them is protective clothing – gas masks and special suits made of rubber or treated synthetic cloth. Biological weapons were banned under the Biological Weapons Convention of 1972, but research production was permitted for defensive purposes. Agreement regarding the limitation of chemical and biological weapons stands high on the agenda of the United Nations Conference on Disarmament, but many states, particularly in the developing world, are reluctant to give up possession of such weapons because they consider them to be a form of deterrence. Iraq's chemical and biological weapons programmes were a prominent issue in the 1990s following the Gulf War and were used to justify the Iraq War of 2003. However, no such weapons were found after Iraq's defeat.
Subjects: Military History.