Saddam used WMD's on Iran, he used them on the Kurds, Assad used them on his own people, then ISIS got things back up and running again and modified what was left and did it all over again. Sarin, chlorine gas, and more. This is widely known by the UN WMD watchdog group. John Kerry has acknowledged it multiple times over, etc..
If that's the best you got, you'd better go back and do some actual research before just repeating stupid things you've heard from wherever you get your information.