Why didn't Hitler order to use all the gas Germany had stored to use on the Soviets when he knew they had lost the war?
Years before WW2 started it was generally assumed in many western societies that if there was another world war then gas would certainly be used. Anyone who saw that old 1936 Movie "Things to Come" will know that it predicted the use of gas in strategic bombing. Today we are so used to Movies & TV shows that depict a post apocalyptic world, I think that movie was the first do so. In fact many people in the 1930s thought that the devastation strategic bombing would cause would be as cataclysmic as we nowadays imagine the aftermath of a nuclear war.