Agent ‘Shag’ Among Secrets Spilled in Spy Chief’s Diary

The inside story on the discovery of the “Cambridge Five” spy ring, radio-controlled carrier pigeons and a double-agent codenamed “Shag” are among secrets disclosed in the newly released diaries of a Cold War British spymaster.

Guy Liddell was deputy director-general of MI5, the internal security service, from 1945 until 1953, keeping a daily diary that remained secret until its publication today by the National Archives in London. It shows how he discussed the hunt for Soviet moles inside the British establishment with his friends Anthony Blunt and Kim Philby, both later unmasked as members of a group of communist spies recruited at Cambridge University in the 1930s.

The 10 volumes, parts of which are still redacted to protect names and operations, also show how the government was planning for a possible Russian invasion, and how MI5 cultivated “Shag,” a Soviet double-agent, who they hoped would help them catch other spies. In 1949, Shag was summoned to meet a Soviet contact.

“The man meeting him will be smoking a cigarette and have a rubber band on his little finger,” Liddell wrote, describing the arrangements as “quite fantastic.” “Shag will bring out his snuffbox and take a pinch of snuff. The visitor will then ask for a light and offer Shag a cigarette, when the latter will reply that he takes snuff. This will be the all-clear.”

‘Double Cross’

The diaries indicate that Liddell had expectations that Shag might help MI5 repeat one of British intelligence’s great World War II deceptions, the “Double Cross” operation, in which it captured and turned virtually every German spy in the U.K., using them to feed false information back to Berlin. In fact, he was the victim of a much more successful campaign by Soviet intelligence.

By January 1950, Liddell was worried about a Soviet network operating in Britain. Two weeks later, he was consulted about the possibility of prosecuting Guy Burgess, a British diplomat, for going on a drinking binge and publicly identifying U.K. agents during a 1949 visit to Gibraltar.

“My own view was that Guy Burgess was not the sort of person who would deliberately pass confidential information,” Liddell noted. “There was no doubt that drink loosened his tongue.”

In April 1951, MI5 got its first break in a two-year hunt for a mole who’d leaked documents from Washington. Information from the U.S. narrowed the suspects down to two men, one of them Donald Maclean, another diplomat. He was put under surveillance.

‘Gone Off’

By May 18, MI5 began to plan how it would interrogate Maclean. Then, on May 29, Liddell recorded that his “watchers” had lost their man over the weekend. At 11 a.m. he was told that Burgess too had disappeared.

“It seems pretty clear that the pair of them have gone off,” Liddell wrote. That evening, he consulted Blunt.

The records that follow show how Liddell gradually came to suspect his friends Blunt and Philby. At first, he wondered whether Burgess might have learned that Maclean was under suspicion by reading files on Philby’s desk in Washington, where Philby was the British intelligence representative.

By June, Liddell recorded the CIA had marked Philby as “persona non grata.” King George VI was asking questions about Blunt, who was by then a prominent art historian responsible for the royal collection. Liddell reassured the king’s private secretary, Alan Lascelles, who expressed relief, saying the queen was already horrified by Blunt’s atheism.

‘Somewhat Blacker’

By October 1951, Liddell had dropped first-name terms in his diary. “The case against Philby seems somewhat blacker,” he wrote. Still, he successfully argued against interrogating Blunt. By November, he was referring to Philby by a codename, “Peach.” At the end of the year, following a series of interrogations, MI5 told the U.S. it believed Philby was a spy, though it wasn’t able to prove it.

Burgess and Maclean reappeared in Moscow in 1956. It wasn’t until Philby’s 1964 flight to the Soviet Union that British intelligence finally confirmed he too was a traitor. Blunt was also identified as a spy, though his involvement remained secret until 1979, when he was unmasked by the press.

Liddell, who died in 1958, having been passed over for the job of director-general of MI5 in 1953, also offered insights in his diaries into the development of new secret technologies.

“Captain Caiger came to see me. He is our pigeon expert,” Liddell recorded in 1946. “He is, in fact, the nearest thing to a pigeon that I have ever seen. He talks, thinks and dreams about them. Pigeons might be able to home on an electric beam, in other words that you might have radio controlled pigeons. There is apparently a slight suspicion that a man in Scotland is already doing this.”

While Liddell made no further record of this, Chinese scientists announced in 2007 that they had developed remote-controlled pigeons, implanting electrodes in their brains.

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