So you cite the Riegle report, but aren’t actually cognizant of it?
According to the report, there were years between when Iraq was taken off the terrorist list, and when they began the research programs. When they began acting out, they got put right back on the naughty list. Even at that, what the US sold them was trivial.
Also, you should understand what anthrax is. Iraq has had anthrax for at least a few hundred years. Pretty much every nation with ungulates has anthrax. What they were given were reference samples...like much of the rest of the world. As for the quantity of fifty, that’s like saying three boxes of .22 constitutes an arsenal.
There are posts above that go into more detail.
There are many valid points concerning the Riegle report that have never been deemed invalid. Your point of Anthrax already being in Iraq is misses the point of weapons exportation from the US. Sure, Iraq could have harvested such Bacillus, but there was no need, for We helped to supply them. And later, such ownership of Bacillus was used as a Casus belli!