But WP plans showed heavy use of Chem on Day One, and after Nixon pulled the 'B' from US NBC, it was a WMD is a WMD is a WMD.
FWIW, I was stationed with a US Army combat engineer battalion in the early 80's. We trained a heck of a lot more for chemical warfare thrown at us than we did for nukes as I recall. I'm really glad we never had to fight in central Europe. The idea of my unit rushing to the Fulda Gap to try and get mines put in before the Soviet tanks showed up did not sound like it was gonna be a fun time at all.