Chemical Warfare, the Second Worst Idea in Modern Warfare
WWI did not only see the first deployment of tanks, but also the first large-scale, industrialized use of chemical agents as a weapon of war. According to most historians, the first use of chemical agents on the battlefield was the use of poisoned arrows by various Greek armies during the Bronze Age. Numerous references have been made throughout history of the regular poisoning or contamination of water sources to frustrate the march of large armies. In small wars around the world, this is still a common tactic. The Chinese were known to deploy arsenical smoke against their enemies, but it was not until the industrial era that things turned really nasty.
During the Crimean War, and in particular during the during the siege of Sevastopol, it was suggested that artillery canisters armed with cacodyl cyanide, a blood agent, might help to move things along. The British, however, the main players in the war, declared this an ungentlemanly way of fighting, as dastardly as poisoning wells, and they would not hear of it. The same basic proposal, this time using chlorine gas, was made during the American Civil War, but for reasons of bureaucratic incompetence no such thing was ever seriously deployed.
It was during WWI that the first real use of chemical weapons on the battlefield began. The Hague Declaration of 1899, and the Hague Convention of 1907 prohibited the use of ‘poison or poisoned weapons’ in warfare, but despite this, more than 124,000 tons of gas were produced by the end of World War I. Although by no means alone, the Germans were the main culprits in this regard, initially firing chemical-laced shells at both Allied and Russian positions, and then in 1915, during the Second Battle of Ypres, hitting French and Canadian troops on a wide front with chlorine gas.
In total, some 50,965 tons of pulmonary, lachrymatory and vesicant agents were deployed by both sides, including chlorine, phosgene, and mustard gas. Official statistics put total casualties at about 1.3 million, no small number of whom were civilians.
The Soviet Union made occasional use of gas to suppress internal rebellions, but the next major use of chemical weapons on the battlefield occurred in Ethiopia and Libya in the 1930s as the Italians sought to suppress local resistance to their occupation. This was in clear contravention of international treaty, and remains something of a stain on the military reputation of Italy.
The Germans, of course, killed millions of Jews by the use of poison gas, but it is debatable whether this can be defined as warfare in the conventional sense. In small wars in the post-war period, such as the Rhodesian bush war, limited use of contaminated clothing has been recorded. It was in the Iran/Iraq War of the 1980s, however, that chemical weapons reappeared on a large scale, and since then in both Iraq and Syria.
This method of fighting a war has always been discredited, and no major conventional armies would admit to making use of it today, although significant stockpile of chemical weapons still exist in many parts of the world.