PS. Moreover, large quantities of mustard agent were found in Syria in 2013.
1: http://www.iranchamber.com/history/articles/chemical_warfare...
https://en.wikipedia.org/wiki/Iraqi_chemical_weapons_program...
This looks implicating to me to a degree that there is no doubt in my mind that these governments supported the chemical weapons program of Iraq. I also read that there were actually German soldiers on the ground during the Iran-Iraq war that helped the Iraqis use the chemical weapons correctly, although there is no proof for that other than a few people who testified. I at least believe this is possible.
But yes, they wanted Iraq to destroy Iran, when they saw that they couldn't do it they wanted the weapons gone.