Remember that we didn’t know about radiation poisoning before we used the bombs on Japan. Also, reflect on what the US did with the Marshall Plan after the war.
I am sure if Germany used mustard gas or some other chemical agent we would have dropped it on them in greater quantities and with more effect. I can’t imagine what we would have done during the middle of the war if we had truely understood the conditions in the German POW camps. War is about winning. Please don’t moralize about it after.