Summary
Overview
This episode chronicles the dramatic defection of Cambridge spies Donald Maclean and Guy Burgess in 1951, examining how Kim Philby, as MI6's man in Washington, watched the investigation close in on his fellow Soviet agents. The episode details the supersecret Venona codebreaking operation that exposed Soviet penetration of Western intelligence, Philby's desperate attempts to warn Maclean while covering his tracks, and the fateful decision to use the erratic Guy Burgess as a courier - a choice that would prove catastrophic for the entire spy ring.
The Venona Project: Breaking Soviet Codes
Philby gains unprecedented access to one of the West's deepest secrets: Venona, a codebreaking operation to decrypt Soviet intelligence messages from World War II. The project, so classified that even President Truman wasn't briefed, revealed approximately 200 Soviet agents operating in the US during the war. Philby, ironically, is given a pass to Arlington Hall to watch codebreakers work - essentially allowing him to surveil the very investigation that could expose him.
- Venona was only declassified in 1995, 50 years after it began
- The Soviets made a printing error and reused one-time pads, making their supposedly unbreakable codes vulnerable
- Venona revealed approximately 200 Soviet agents operating in the US during the war, with at least five in the OSS
- Philby had a pass to Arlington Hall and could watch lead codebreaker Meredith Gardner work on Venona messages
- Messages referenced a 'Stanley' and a 'valuable London network' - actually Philby himself
" It is actually impossible. It is impossible. It's literally impossible. "
Donald Maclean's Spectacular Crack-Up
Donald Maclean, the ideological communist working at the Foreign Office, begins a spectacular mental breakdown under the pressure of espionage. His behavior becomes increasingly erratic, from barking like a dog outside his Cairo home to embarking on a 48-hour bender that culminates in trashing an American secretary's apartment - destroying her bath and flushing her underwear down the toilet. Despite these alarming incidents, he's promoted to head the America's desk for the Foreign Office.
- Maclean was the most ideologically committed communist of the Cambridge spies, a true Marxist ideologue
- In Cairo, he would bark like a dog while drunk to be let into his home
- On a 48-hour bender in May 1950, he trashed an American secretary's flat, breaking the bath and flushing her underwear
- Despite his breakdown, Maclean was made head of the America's desk in November 1950
- By spring 1951, Venona revealed Homer's pregnant wife was in New York - pointing directly to Maclean
" I think McLean is a communist. You know, he's a kind of Marxist ideologue. "
" they take a mirror and they try and smash the mirror on the bath. But the bath breaks and not the mirror, which I find a bit weird. "
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