MI6 played a substantial role in the Cold War. The organization was able to turn Komitet Gosudarstvennoi Bezopasnosti (KGB) agent Colonel Oleg Penkovsky, who provided vital intelligence information on the Soviet Union in the early 1960s. Colonel Penkovsky smuggled photographs of some 5,000 secret Soviet documents before he was discovered and executed by Soviet authorities in 1963.
MI6 had its embarrassments as well. In 1963 one of its top agents, Kim Philby, fled to Moscow and was exposed as a Soviet spy and member of the Cambridge Five spy ring. Later it was revealed that Philby, who had been British intelligence liaison officer with the CIA, had been able in 1951 to warn another member of the Cambridge Five ring, Guy Burgess, that he was under investigation. Burgess and yet another member of the group, Donald Maclean, then fled to the Soviet Union. Another embarrassment for MI6 occurred when it sent navy diver Commander Lionel Crabb on a never-explained mission around the hull of the Ordzhonikidze, the Soviet ship that had brought Soviet leaders Nikolai Bulganin and Nikita Khrushchev to Britain on a state visit. Crabb's disappearance led to a parliamentary inquiry and the dismissal of a number of MI6 employees.
Arthur M. Holst and Spencer C. Tucker
Deacon, Richard. The Cambridge Apostles: A History of Cambridge University's Elite Intellectual Secret Society. New York: Farrar, Straus and Giroux, 1986.; Knightley, Phillip. The Second Oldest Profession. New York: Norton, 1987.; Strong, Kenneth. Men of Intelligence: A Study of the Roles and Decisions of Chiefs of Intelligence from World War I to the Present Day. New York: St. Martin's, 1972.