They say that diplomacy is the fine art of saying "Nice doggie" until you can find a big enough rock. My hunch is that they have known since Day One that Iraq was behind the anthrax, but until they had the antibiotics stockpiled and the smallpox vaccines ready (in case he has that, too) it would have put the entire country at risk to move against him. Plus they needed time to come up with a plan -- and move the resources into place -- to hit so hard, so fast, that none of that stuff gets out of there while the battles are going on.
This is a very tricky thing they are going to attempt. People here could die in this war. But... it was coming sooner or later. Better now than when he has more of it, or more of it pre-positioned here.
I slight understatement I must say. Lots of people will die here.
They turned to the hot topic of anthrax. The powder in the letter mailed to Senator Daschle's office had been found to be potent, prompting officials to suggest its source was likely an expert capable of producing the bacteria in huge amounts. Tenet said, "I think it's AQ -- meaning Al Qaeda.""I think there's a state sponsor involved. It's too well thought-out, the powder's too well refined. It might be Iraq, it might be Russia, it might be a renegade scientist, perhaps from Iraq or Russia."
"I'm not going to talk about a state sponsor." Tenet assured them.
"It's good that we don't." said Cheney, "because we're not ready to do anything about it."
Bob Woodward, Bush at War (2002), pp. 248-249.