Was there planned use of Chemical weapons by the Allies if the war turned more in favor of the Axis? Or were both sides afraid of Chemical retaliation? Would the Allies have used CBRN to retaliate if Japan launched Operation Cherry Blossoms at Night?

I think Churchill had planned on using Chemical weapons if the Germans launched an invasion of Britain. Also, from what I’ve read it looks like a lot of the Chemical weapons stockpiled by the Allies was to be in retaliation for if the Germans used gas during D-Day or if the Japanese used gas on Allied troops. Although the Japanese used Chemical and Biological weapons in China against the Chinese. The Germans had also used toxic smoke and some poison gas against the Soviets. On the other hand, the Germans feared Chemical retaliation by the Allies so they removed or destroyed stockpiles in Italy to prevent a local commander from triggering a chemical attack. So this begs the question, if the war had gone more Germany’s way, would the Allies have used Chemical weapons in an offensive manor? Did the Allies not respond with Chemical attacks out of fear despite the Germans and Japanese using Chemical and Biological weapons? Would there be large scale retaliation in the form of CBRN weaponry if the Japanese had launched a Biological attack on California, or not?


I guess my question would be is did any of the leadership feel chemical weapons would have changed the strategic situation? My impression is they didn’t see it as a war winner so why suffer the negative consequences.

As to whether the Americans would have retaliated to a biological attack is what did they have left to retaliate with? Once you start mass napalming of cities, it’s kinda hard to know what retaliation was left.


As far I’ve read, most of the nations didn’t used chemical weapons as to avoid reprisals and have a WW1 v.2 escalation, and there were several advances on that field during the time (Sarin gass was born here); so I don’t think they would use it if the tide was turned, as there could be a real chance of having chemical bombarment on cities.as reprisals, with the new range of weaponry and bombers.


I remember back in the 80s or 90s that they had found some Mustard Gas shells on some of the islands in the Pacific. There was no nation mentioned as to whose they were. But it could only have been 2, Japan or the US as both occupied the island.


Japan did use poisongas against China before Pearl Harbour.