Saddam's chemical weapons

I know full well about US complicity in Saddam's use of chemical weapons.  In the late 1980s, I was at a x-mass dinner party in Washington, DC and seated next to the Iraq desk officer at the US Department of State.  I kept badgering him about US silence regarding Saddam's use of chemical weapons against Kurds.  And he kept repeating the same response: the US does not have evidence of Saddam's use of chemical weapons.