It doesn't matter what the specific threat is. A nuke would kill tens to hundreds of thousands. VX would kill as many. An infectious virus could kill tens of thousands to millions. A massive anthrax attack would kill thousands. We must let Iraq, specifically, and Islam in general, know that it will be they that are erased from the face of the Earth if these weapons are used.
My personal opinion is that the anthrax came from Iraq, and we should have nuked them then.