As I understand it, inhalation almost requires 'modified' (small size) anthrax spores to contract....and a lot of them.
How hard would it be to smuggle in 100 kilos of high test Iraqi athrax spore?
How many leaky partially sealed envelopes could a gang of terrorists mail, one gram per letter?
Assuming Saddam is not an idiot, and that he has been preparing for this "showdown" since at least 1991, is it not reasonable to plan that he has already moved anthrax by the drum into the USA to serve as his MAD shield, and his poor man' doomsday device in the event MAD fails?
Besides thousands of letters, his agents could throw one kilo glass jar "anthrax bombs" onto subway tracks and into the air intakes for major buildings and arenas. This would kill "only" in the 1000s, but would wreck our economy as the postal service was stone cold shut down, and important buildings were closed for a long time.