On March 30, 1951, a British cryptographer working on the Anglo-American VENONA counterespionage project cracked a coded message from Russian Intelligence which identified Donald Maclean as a Soviet agent. Maclean, son of a Liberal cabinet minister and a graduate of Cambridge University, had worked in the British embassy in Washington for four years, from 1944 to 1948, during which time he had passed to the Russians extremely valuable information on, among other things, the American atomic weapons program. After Washington he moved to the embassy in Cairo, where he suffered a nervous collapse brought on by stress and overdrinking. Nevertheless, after six months’ leave he returned to work for the Foreign Office in London, and was appointed head of the American Department. Before being exposed, he had been in the habit of telling friends that he was a Communist agent. They did not believe him, even after he had punched an acquaintance for saying that Whittaker Chambers had been right in identifying Alger Hiss as a spy. “I am the English Hiss,” Maclean declared.
Maclean the spy presented MI5 with a problem. If he were to be arrested, the Soviets might well realize that their codes had been broken. So the security service, in its almost endearingly Gilbert and Sullivanesque way, contented itself with having him followed by the Special Branch, but only when he was in London, and only during office hours, since MI5 and the Special Branch felt that the overtime that would have to be paid for round-the-clock surveillance could not be justified in the circumstances.
In the meantime, in Washington, Kim Philby, the trusted MI6 liaison officer with American intelligence, and also a Soviet agent, had been tipped off by London that Maclean was about to be exposed. In those days before cell phones and e-mail, Philby had no direct means of warning Maclean. He found a solution in the bizarre figure of Guy Burgess, who was also working in Washington, and had lived for a time there with Philby and his wife. Burgess, a leading member of the Cambridge spy ring, was rapidly falling to pieces. Like Maclean, he had for many years been telling anyone who would listen that he was a spy, but he too was not believed. In Washington, he would spend his days drinking in the bars below Capitol Hill, denouncing America and its policies. At a party at Philby’s house he insulted the wife of a senior CIA officer. In April 1951, in his pink Cadillac, he managed to pick up three drunk-driving charges in three separate states on the same day. London was not amused. Burgess was summoned home by the Foreign Office to face sacking and disgrace.
When Burgess arrived in London, the first person he sought out was Anthony Blunt, who, hearing the news about Maclean, contacted his Soviet controller in London, Yuri Modin, author of an irresistibly jaunty and, according to Miranda Carter, wholly unreliable memoir, My Five Cambridge Friends. In her new biography of …