Dust within the KGB's Own Walls. Crippling Soviet Operations via KGB Double Agents

The KGB was built on the premise that it could see everything. It watched dissidents, monitored diplomats, planted agents in every Western capital, and cultivated moles inside MI6 and the CIA for decades. Yet within its own corridors, something it could never fully control was quietly taking root - the conscience, or the disillusionment, of its own officers. The story of how Western intelligence agencies turned the KGB's greatest weapon against itself is one of the most consequential, and most quietly devastating, chapters of the Cold War.
Oleg Gordievsky, who began passing intelligence to MI6 in 1974, rose to become the KGB's rezident-designate in London - the USSR's chief spy on British soil - while simultaneously feeding Moscow's innermost thinking to British and American analysts. His intelligence helped defuse the nuclear paranoia of Operation RYAN, in which Soviet leadership under Yuri Andropov had grown genuinely convinced that NATO was preparing a pre-emptive strike.
A decade of his work reshaped Western understanding of Soviet intent at the most dangerous juncture of the late Cold War. When he was finally exposed - betrayed not by MI6, but by CIA officer Aldrich Ames, who was himself selling names to the KGB - Gordievsky escaped the USSR through Operation Pimlico, a plan involving a Safeway bag held outside a Moscow bakery as a signal that he needed immediate extraction.