The operation involved the fake defection in place of a US Army sergeant based in Washington, D.C. who, in return for hundreds of thousands of dollars over two decades, provided information to Soviet intelligence (GRU) as agreed by the Joint Chiefs of Staff.
[1] Cassidy provided over 4,000 documents on a mixture of real and non-existent research into the new gas, with the US intending to waste Soviet resources attempting to duplicate the work.
[6][7][8] David Wise, in his book Cassidy's Run, implies that the Soviet program to develop the Novichok agents may have been an unintended result of the misleading information.
[10] A similar, and arguably more significant, disinformation operation was run by the FBI via double-agent Dmitri Polyakov, feeding the Soviet Union the false information that the US was covertly continuing with its biological weapons program despite public announcements to the contrary.
The disinformation may have been one reason which led the Soviet Union to expand its biological weapons program, and a near-universal belief into the 1990s among its scientists that they were mirroring US efforts.