How do I know that ?
The Federation of American Scientists said so.
Repeatedly.
Kept saying so, even when the Russians were using a lethal agent called "Yellow Rain" in Afghanistan.
Kept saying so by their silence when the friendly natives of Uzbekistan proudly displayed the Russian Chemical and Biological warfare labs that had been left behind.
I assume the revelation Russia has vast stockpiles of chemical, biological, and nuclear weapons will be blamed upon the Foul Counter-Revolutionaries who took over in kindly, peace-loving, admirable Mother Russia.
After all, the FAS couldn't have been wrong !!!