In Peter Schrijver's excellent _The Crash of Ruin_:

"The War Department was convinced that the German military was thoroughly prepared for chemical warfare and that its stock of war gases were plentiful. . . . The field manual on the rules of land warfare informed the GIs matter-of-factly: 'The practice of recent years has been to regard the prohibition against the use of poison as not applicable to the use of toxic gasses.'" (pg. 61)

How could the Roosevelt administration and its war machine have been so wrong about Hitler's intentions regarding battlefield deployment of WMDs? Was this wilful disregard or incompetence? FDR should have been impeached, Marshall flogged, Eisenhower forced to quit smoking and stop wearing that silly jacket.