politician Sir Donald Maclean, was already on staff. “It's like being a lavatory attendant,” Maclean would say later of espionage; “it stinks, but someone has to do it.”
Though he worked at making friends, Cairncross was not a success in the Foreign Office. “Cairncross was always asking people out to lunch,” one of his colleagues, John Colville, remembers. “… He ate very slowly, slower than anyone I've ever known.” Colville judged him “a very intelligent, though sometimes incoherent, bore.” In 1938, Cairncross transferred from the Foreign Office to the Treasury, probably at the request of the NKVD. Cairncross's real espionage breakthrough came in September 1940, a year into the European war, when Lord Hankey, minister without portfolio in Winston Churchill's War Cabinet, appointed him his private secretary. Hankey had full access to top secret War Cabinet papers and oversight of British intelligence. He also chaired the Scientific Advisory Committee.
It was probably John Cairncross who first passed information on Anglo-American atomic-bomb research to “Henry,” the Cambridge Five's London NKVD control Anatoli Borisovich Gorsky, at the end of September 1941, when the Wehrmacht was besieging Leningrad and Igor Kurchatov was demagnetizing ships in Sevastopol. Gorsky — “a short, fattish man in his mid-thirties, with blond hair brushed straight back and glasses that failed to mask a pair of shrewd, cold eyes” according to one of his wartime agents — was “Vadim” to Moscow Center, the NKVD home office. Cairncross was probably “List.” Vadim's report, “#6881/1065 of 25.IX.41 from London,” summarized a meeting of the British Uranium Committee held on September 16. The information corresponds to information contained in the secret “Report by MAUD Committee on the Use of Uranium for a Bomb” prepared that summer for the British Cabinet and transmitted to the United States. At some time Moscow Center acquired a complete copy of the MAUD report.
“The uranium bomb may very well be developed within two years,” Vadim's report began dramatically. Measurements of U235 cross sections would be accomplished by December. The British firm Metropolitan Vickers had been commissioned to develop a twenty-stage gaseous-diffusion pilot plant, a task which had “high priority,” construction to begin “immediately.” The government had contracted with Imperial Chemical Industries (ICI) for uranium hexafluoride, the gaseous form of uranium, which the Vickers plant would process.
Some of the information in this first transmission was garbled. A second transmission sent October 3 cleared up the confusion. “It is thought that the critical mass [of U235] falls within the range from 10 to 43 kg,” the document reported. ICI had already produced three kilograms of uranium hexafluoride. “Production of U235 is realized by diffusion of uranium hexafluoride in a vaporized state through a number of membranes consisting of a grid of very fine wire.” (This configuration was German emigre chemist Franz Simon's first approximation of a diffusion “membrane” or “barrier” — he had pounded out a kitchen strainer to demonstrate the idea to his Oxford staff.) In 1939, Yuli Khariton and Yakov Zeldovich had dismissed gaseous diffusion as an impractical method of separating U235; here was information that the British considered it superior. The document reported problems, however. “Development of the separation plant design is meeting with serious difficulties.” Vadim enumerated the perverse physical characteristics that made “hex” hellish stuff — the heavy, corrosive gas destroyed lubricant, dissociated in the presence of water vapor and attacked equipment. A gaseous-diffusion plant would be huge, the British had calculated, 1,900 ten-stage units occupying a plant area of some twenty acres.
From gaseous diffusion the report then veered back to the bomb, echoing Peierls and Frisch's early realization that a weapon that derived its explosive force from nuclear fission would have unique characteristics: “It should be noted that besides the uranium bomb's tremendous destructive effect, the air at the site of the explosion will be saturated with radioactive particles capable of killing everything alive.”
September 1941 was a banner month for Soviet nuclear espionage. While Vadim was reporting from London, Morris Cohen weighed in from New York. Cohen had married a fellow Communist, Leontine Patka, known as Lona, the day Germany invaded the USSR. The invasion had depressed him, but after he had mulled it over for a few days he had revealed his affiliation to his wife and convinced her to join him in espionage work. Together they had already collected and passed along information from an engineer in Hartford on a new aircraft machine gun, even delivering a prototype of the machine gun to Morris's Soviet contact, the long barrel concealed in a bass viol case. Now Cohen reported a remarkable development. An American physicist whom he knew from Spanish Civil War days had contacted him for an introduction to Amtorg, the Soviet trading corporation in New York that clandestinely organized North American espionage. The physicist told Cohen he had been invited to work on a secret project to develop an American atomic bomb. Cohen wanted to know if he could recruit the man. Moscow Center approved.
Lavrenti Beria received these independent reports of Allied nuclear-research activity with his habitual cynicism. Anatoli Yatzkov, the NKVD's New York
Early in 1942, a new GRU volunteer began contributing to the volume of information reaching the Soviet Union. He was a refugee in England from Nazi Germany, a devoted Communist already gone underground and an exceptional young physicist and he worked for Rudolf Peierls:
I… found many problems piling up on the theoretical side, and I could not deal with all of them fast enough… I needed some regular help — someone with whom I would be able to discuss the theoretical technicalities. I looked around for a suitable person, and thought of Klaus Fuchs.
Born in 1911 in Russelsheim, in the Rhine Valley south of Frankfurt, Fuchs at thirty-one had already seen enough conflict and tragedy for a lifetime. He claimed later that he had “a very happy childhood,” but it culminated with his mother's violent suicide — she drank hydrochloric acid — when he was nineteen. His elder sister Elizabeth would also be a suicide, though her act may have been protective: a Communist who was active politically against the Nazis, she jumped in front of a train when she was about to be arrested. Fuchs's father Emil was a politically contentious parson who left the Lutheran Church when Fuchs was fourteen and became a Quaker. “My father always told us that we had to go our own way,” Fuchs remembered, “even if he disagreed. He himself had many fights because he did what his conscience decreed, even if these [sic] were at variance with accepted convention.” Klaus Fuchs would become his father's son, but he broke away from his father's philosophy, he said, over pacifism.
Fuchs joined the Socialist Party at the University of Leipzig, where he began studying physics and mathematics in 1930. After two politically active years he went on to the University of Kiel. There he quit the Socialists over the party's decision to support the presidency of Paul von Hindenburg, the conservative field marshal who would pass the chancellorship of Germany to Adolf Hitler. “At this point,” Fuchs recalled, “I decided to oppose the official policies openly, and I offered myself as a speaker in support of the Communist candidate.” He joined the Communist Party soon afterward and worked actively on its behalf in student politics, his work culminating in a strike which the Nazi leaders called in SA brownshirts to break. “In spite of that I went there every day to show that I was not afraid of them. On one of these occasions they tried to kill me and I escaped.”
After the Reichstag fire early in 1933 that gave Hitler an excuse to invoke a state of emergency and round up the opposition, Fuchs went underground:
I was lucky because on the morning after the burning of the Reichstag I left my home very early to catch a train to Berlin for a conference of our student organization, and that is the only reason why I escaped arrest. I remember clearly when I opened the newspaper in the train I immediately realized the significance and I knew that the underground struggle had started. I took the badge of the hammer and sickle from my lapel…
“I was ready to accept the philosophy that the Party is right,” Fuchs continues, “and that in the coming struggle you could not permit yourself any doubts after the Party had made a decision.” Long afterward, Rudolf Peierls would ask Fuchs how a scientist could accept Marxist orthodoxy and would be shaken by the “arrogance and naivete” of his answer. “You must remember what I went through under the Nazis,” Peierls reports Fuchs answering. “Besides, it was always my intention, when I had helped the Russians to take over everything, to get up and tell them what is wrong with their system.”
