Iraq has shaken that dubious trump card at us and I believe they will use it when we attack. I guarantee you if any group of Jews dies from just one poison gas scud attack - Israel will go bonkers and retaliate, no matter how strongly we urge them to use restraint.
Just my opinion.
You say that as if it's a sign of instability or something.
How do you think we would/should react if Iraq killed "any group of Americans" from "just" one poison gas scud? "No matter how strongly" some third party nation urged us "to use restraint"?