Gas! Gas! Gas!
GAS GAS GAS was the shouted warning indicating a chemical attack was underway. This has expanded to chemical and biological as the scientists come up with evermore nasty killers.
Although medieval types has been using quicklime as a chemical weapon since about 1100, the first proper use of gas as a weapon of war was in August 1914. The French fired tear-gas grenades (xylyl bromide) against the German army. Pandora's scary box had been opened...
The first recognized use of poison gas (and often used as proof the Germans started it) was chlorine gas on the 22 April 1915 at the Second Battle of Ypres. The effects of chlorine gas are pretty nasty. Within seconds of inhaling its vapour it destroys the victim's respiratory organs, bringing on choking attacks. Cotton pads were manufactured as a basic gas mask which were dipped in a solution of bicarbonate of soda and held over the face. Soldiers were advised that holding a urine <either your own or a buddies> drenched cloth over their face would serve in an emergency to protect against the effects of chlorine.
Improving on Chorine was Phosgene which was much nastier. While Chlorine was potentially deadly, it caused the victim to violently cough and choke whereas Phosgene caused much less coughing with the result that more of it was inhaled. Phosgene had a delayed effect when apparently healthy soldiers would go down with phosgene gas poisoning up to 48 hours after inhalation. Adopted by both German and Allied armies.
Next poison up was used against the Russians at Riga in September 1917. This was mustard gas (or Yperite) fired in modified artillery shells. Mustard gas, which is almost odourless, caused serious blisters both internally and externally if exposed for several hours. Protection against mustard gas proved more difficult than against either chlorine or phosgene gas foreshadowing the sort of protection required today.
Other types of gases produced during 1914-18 included bromine and chloropicrin. The French army made use of a nerve gas obtained from prussic acid however the most widely used were chlorine, phosgene and mustard.
By 1918 soldiers on both sides had filter respirators (using charcoal or antidote chemicals) and were highly effective. They were difficult to work in and very tiring but at least you didn't drown with fluids in your lungs as a result of gas.
Poison gas was outlawed in 1925 ... with predictable results (ie rogue states have been using it ever since).
By the time the 1939-45 conflict rolled round far far more deadly gases were available. Cyanide, carbon monoxide and cyanogens chloride all impede the ability of blood to absorb oxygen. Unable to gain oxygen, the body just shuts down. Death is rapid, sure and relatively painless.
Nerve gas was also much more readily available in World War Two. Nerve gases attack the body's central nervous system. Symptoms are nausea, vomiting, muscular twitching, convulsions, cessation of breathing and obviously after all that ... death. Tabun was developed by the Germans. Sarin and Soman were also developed as nerve gases. Of the three, Soman was the most deadly. From inhalation, it is only a matter of tens of seconds of exposure before a victim goes into convulsions.
We in the UK weren't immune to toying with these killers. Britain experimented with anthrax on remote Scottish islands to see its impact on the animal population there.
Even though there were thousands of tonnes of these killers available to be used, in a war where millions were exterminated, nuked and firebombed ... Gas was never used thus making a mockery of whole nations carrying gas masks all day everyday.
EXCEPT For Japan.
Japan had done quite a bit of experimentation with germ warfare, mostly in the form of infected fleas. The program got its start in the 1930s when Japan occupied Manchuria, and later in their invasion of China.
Several epidemics of cholera, typhoid, anthrax and bubonic plague were reportedly caused in China by Japan's "Uji" bombs, which were designed specifically to burst hundreds of feet above the ground, and rain infected fleas upon the populace killing as many as 50,000 Chinese people over six years. Masks would have been of F all use!
North Korea has claimed since 1951 that the UN and America in particular used chemical and biological weapons throughout the conflict. The UN and US categorically denied the allegations.
Ignoring for a moment McArthur's desire to nuke China, no such NBC weapons were used and the US has gone on record repeatedly to say so.
Most notably General Matthew Ridgway, Commander U.N. forces Korea, stated before the U.S. Congress on May 22, 1952: “I am constrained at this point to refer again to the officially propagated allegations of Communist leaders that the United Nations command in Korea has employed both germ and gas warfare. I wish to reiterate what I have repeatedly stated publicly, that these allegations are false in their entirety; that no element of the United Nations command has employed either germ or gas warfare in any form at any time.”
Documents uncovered in Soviet archives demonstrated that the North Koreans, Chinese, and Soviet authorities cooperated to deliberately fabricate bogus “evidence” in an attempt to bolster these false charges. This included infecting North Korean prisoners with naturally occurring plague and cholera, some of which was obtained from China.
While defoliants could be defined as a chemical weapon (causing chemical burns and cancer), the first recognized use of a gas weapon in Nam was tear gas dropped onto a Viet Cong fortified area of jungle in 1965. Spiced up tear gas causing vomiting and diarrhea was also used sometimes unofficially as in theory only presidential ok could allow the use of gas weapons. CNN alleged in 1998 that U.S. military forces used Sarin nerve gas in Laos in 1970 to kill American defectors. This story was retracted and the Pentagon denied it ever happened but the whispering has gone on.
Argentine forces during the 1982 invasion of the Falkland Islands used tear gas when assaulting the Marine barrack buildings. The Booties had however packed their sunday frocks and scurried off to annoy the hell out of the Argies elsewhere on the island.
Iran Iraq War
This 8 year war (1980-88) is often compared to World War I. Tactics such as trench warfare, machine-gun posts, bayonet charges, barbed wire, Iran human wave attacks and Iraq's use of chemical weapons (such as mustard and Sarin gas) on just about everyone. These weapons came in the main from the USA, Germany, France, Holland, Egypt and India. Spain and China supplied munitions to fire the chemicals. Even the United Kingdom paid for a chlorine factory that ended up being used for manufacturing mustard gas. Over 100,000 Iranians died (out of a total death toll for the war of 1 million) through chemical attacks.
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