On the radio this morning, there was a reporter talking about how Saddam Hussein has already given the go ahead to his commanders authorizing the use of chemical and biological weapons against US troops in the event of an invasion.

I am curious why he would make this threat.  Is he under the impression that we will NOT respond with our own Weapons of Mass Destruction?  

Wasn't there a statement by the US in the original Gulf War to the effect that we considered the use of chemical and biological agents a WMD and that we would respond with nukes?

Has there been a change in our policy in regards to our troops being gassed or poisoned?