The U.S.S.R. executed alleged* U.S. mole Adolf Tolkachev on this date in 1986.
Tolkachev (English Wikipedia entry | Russian) had grown up during the Stalin years — background he would cite by way of explaining his subsequent actions against the Soviet state and its “impassable, hypocritical demagoguery.” (His wife had been orphaned by the purges of the 1930s.)
Inspired, he said, by the dissidence of writer Aleksandr Solzhenitsyn (expelled from the Soviet Union in 1974) and bomb engineer Andrei Sakharov (prevented from leaving the Soviet Union to collect his 1975 Nobel Peace Prize), Tolkachev in the late 1970s boldly made contact** with U.S. intelligence officers at the Moscow petrol station where they fueled their cars. He immediately became one of the Americans’ most valuable assets — literally so; the 2015 book about him is titled The Billion Dollar Spy.
Tolkachev’s day job for a top-secret aviation laboratory gave him access to priceless documents on the development of the Soviet aircraft, radar, and weapons guidance and using a James Bond-esque miniature Pentax supplied him by Langley, Tolkachev snapped photos of those secrets for delivery to the Americans. It’s claimed — this is the reason for the billion-dollar stuff — that Tolkachev’s tips drove research and development in American military technology in vastly more effective directions.
The spy himself was paid for his risks in rubles and in a U.S. escrow fund pending his eventual defection.
* The date is supplied courtesy of a September 25, 1986 Politburo document referring to Tolkachev’s execution “yesterday”.
Note however that the prevailing Tolkachev story as presented in this post is disputed by CIA historian Benjamin Fischer, who has argued that “Adolf Tolkachev” was a KGB prank on its opposite number in the Cold War’s Spy vs. Spy game.
** Tolkachev really had to insist upon himself to his American handlers: the first four times he approached US embassy personnel with overtures he was rebuffed or ignored as a probable Soviet plant.