I mean you laugh because we failed to turn anything up in Desert Storm, but the US knew Saddam had chemical weapons mostly because we had the receipts from helping supply him with them in the 80’s to fight Iran. They just left that part out during the war hype coverage https://foreignpolicy.com/2013/08/26/exclusive-cia-files-prove-america-helped-saddam-as-he-gassed-iran/

https://www.govinfo.gov/content/pkg/GAOREPORTS-NSIAD-94-98/html/GAOREPORTS-NSIAD-94-98.htm