A government official with direct knowledge of the investigation has said that the totality of the evidence so far suggests it is unlikely the spores were originally produced in the former Soviet Union or Iraq."
I'm glad you provided that quote from the WP ...it seems to me it's a statement that was deliberately crafted to entrap the not very scientifically literate press.
The first part of the statement indicates that the coating technology is indicative of either the US, Soviet Union or Iraq.
The second part of the statement seems to eliminate the Soviet Union and Iraq (inferring the anthrax came from the US to the casual reader).
What it actually infers is that the original spore strain ...the Ames strain ...came from the US ...which is true.
Essentially, it says that the US originally provided the anthrax stock to the Soviet Union and Iraq ...this in no way eliminates Iraq from being the prime culprit as the source of the Daschle anthrax sample.
In fact it does more than that. The US never weaponized the Ames strain. This quote appeared in the October 15, 2001 issue of Chemical & Engineering News (written before the strain was known):
"It's bad news if it turns out to be the Ames strain," says Bill Patrick, who headed the U.S. bioweapons program before it was terminated in 1969. "Ames is perhaps a bit more virulent than the [Vollum 1B] strain the U.S. weaponized."
I am shocked the Washington com.Post could have missed this. (/sarcasm)