Considering that our air force rules the world's skies, there is very little chance of chemical weapons being delivered against us in large quantities.
I'm more worried about Saddam's favorite toys, the chemical coctails which he has proven effective on his own citizens. In addition, I cannot help but wonder if he has aquired a fully funtional, "lost" warhead. Even if he can't aquire a nuke, he still has the chemical weapons.
Bios are nonsense, you're right...they are too untrustworthy and can kill the hopeful invador with the same impugnity as they could kill any of us...in addition, there's the problem with wind current, natural immunity, chemically induced immunity, etc.
West Nile, BTW isn't a bioweapon. It WILL kill...but it was a simple importation of a certain desease dure to our habit of global travel, and though a few Islamic nutballs were drooling about the possibility of how it might kill off all the evil infidels of the Great Satan, it mutated into a less virulent form (another reason bios are a bad weapon). Still, it was only brought to this country by chance, not intent. The people who get all panicky about West Nile get on my nerves too....even though I DID come down with a more virulent strain which nearly killed me, though I'm neither particularly old nor weak.
Considering that our air force rules the world's skies, there is very little chance of chemical weapons being delivered against us in large quantities.