What we don't know for a fact is whether or not countries such as Russia, Iraq, China, Pakistan, etc. ever managed to obtain samples of the strain through espionage. There have been unsubstantiated reports recently that strongly indicate that the old Soviet Union managed to penetrate Ft. Detrick at some time in the '80s. Furthermore, government and military security at our facilities during the Clinton '90s was a sick joke (Los Alamos, anyone?)
Frankly, I have my doubts that our government would ever openly acknowledge that a country such as Russia or Iraq managed to steal Ames even if they knew for a fact it were true.
They shipped the Ames strain all over the world. No one had to "steal" it ~ it was the control standard for the development of anti-anthrax drugs and other chemicals for use in the leather and wool industries.