Brief History of Chemical Weapons Use

Although chemicals had been used as tools of war for thousands of years—e.g. poisoned arrows, boiling tar, arsenic smoke and noxious fumes, etc.—modern chemical warfare has its genesis on the battlefields of World War I.

During World War I, chlorine and phosgene gases were released from canisters on the battlefield and dispersed by the wind. These chemicals were manufactured in large quantities by the turn of the century and were deployed as weapons during the protracted period of trench warfare. The first large-scale attack with chlorine gas occurred 22 April 1915 at Ieper in Belgium. The use of several different types of chemical weapons, including mustard gas (yperite), resulted in 90,000 deaths and over one million casualties during the war. Those injured in chemical warfare suffered from the effects for the rest of their lives; thus the events at Ieper during World War I scarred a generation. By the end of World War I, 124,000 tonnes of chemical agent had been expended. The means of delivery for chemical agent evolved over the first half of the twentieth century, increasing these weapons’ already frightening capacity to kill and maim through the development of chemical munitions in the form of artillery shells, mortar projectiles, aerial bombs, spray tanks and landmines.

After witnessing the effects of such weapons in World War I, it appeared that few countries wanted to be the first to introduce even deadlier chemical weapons onto the World War II battlefields. However, preparations were made by many countries to retaliate in kind should chemical weapons be used in warfare. Chemical weapons were deployed on a large scale in almost all theatres in the First and Second World Wars, leaving behind a legacy of old and abandoned chemical weapons, which still presents a problem for many countries.

During the Cold War, the United States and the Soviet Union both maintained enormous stockpiles of chemical weapons, amounting to tens of thousands of tonnes. The amount of chemical weapons held by these two countries was enough to destroy much of the human and animal life on Earth.

Iraq used chemical weapons in Iran during the war in the 1980s, and Iraq also used mustard gas and nerve agents against Kurdish residents of Halabja, in Northern Iraq, in 1988. The horrific pictures of Halabja victims shocked the world at the time of the negotiations in Geneva on the Chemical Weapons Convention. The two most recent examples of the use of chemical weapons were the sarin poisoning incident in Matsumoto, a Japanese residential community, in 1994, and the sarin attack on the Tokyo subway in 1995, both perpetrated by the Aum Shinrikyu doomsday cult. These two attacks re-focussed international attention on the potential use of chemical weapons by terrorists, and on the dangers posed by chemical weapons.

The devastating impact chemical weapons have had in the past, and the potential for the use of modern—even more deadly—chemical agents not only by States at war but in other violent conflicts and by non-State actors, provide the imperative for the international effort to uphold the ban on such weapons and to work towards the complete, global elimination of chemical weapons.