Skip to Main Content

Counterintelligence: Operation Shocker

Counterintelligence can be described as activities designed to prevent or thwart spying, intelligence gathering, and sabotage by an enemy or other foreign entity. This guide provides books, articles, reports, websites, and videos on the subject.

Operation Shocker

Operation Shocker was a 23 year counterintelligence operation against the Soviet Union, run by the FBI.  It involved using U.S. Army First Sergeant Joseph Cassidy to provide the Soviet Union, over two decades, with information on nerve gas in exchange for money.  This was with the intent to waste Soviet resources.


SGT Joe Cassidy was an Army sergeant who was the FBI's longest running agent of the Cold War.  Selected by the FBI as a "dangle" to lure Soviet intelligence officers to recruit him as a spy, Cassidy provided the Soviet Union with U.S. nerve gas information for over 20 years.  He gave them a mix of both real and false information, in exchange for money. This operation allowed the U.S. to learn more about Soviet intelligence operations in America, and also allowed the FBI to unearth deep-cover Soviet moles operating in  the U.S. who were assigned to work with Cassidy.