Double-Cross System
The wartime MI5 program that turned every German agent in Britain into a deceiver
Overview
The Double-Cross System, run by the wartime Twenty Committee, caught every German agent sent to Britain and turned them into channels of controlled falsehood. Wireless operators arrested on arrival became instruments of deception, and figures like the Spaniard Juan Pujol Garcia, codenamed Garbo, built phantom spy rings that Berlin trusted completely. The system anchored the Fortitude deception that kept German reserves away from Normandy in 1944. It is widely ranked among the most successful counterintelligence operations ever conducted. Every delivered message was crafted in London and cleared by committee before transmission.
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