The GRU (military intelligence) recruited the ideological agent Julian Wadleigh, who became a State Department diplomat in 1936. The NKVD's first US operation was establishing the legal residency of Boris Bazarov and the illegal residency of Iskhak Akhmerov in 1934.[5] Throughout, the Communist Party USA (CPUSA) and its General Secretary Earl Browder, helped NKVD recruit Americans, working in government, business, and industry.[citation needed]
Other important, low-level and high-level ideological agents were the diplomats Laurence Duggan and Michael Whitney Straight in the State Department, the statistician Harry Dexter White in the Treasury Department, the economist Lauchlin Currie (an FDR advisor), and the "Silvermaster Group", headed by statistician Greg Silvermaster, in the Farm Security Administration and the Board of Economic Warfare.[6] Moreover, when Whittaker Chambers, formerly Alger Hiss's courier, approached the Roosevelt Government—to identify the Soviet spies Duggan, White, and others—he was ignored. Hence, during the Second World War (1939–45)—at the Tehran (1943), Yalta (1945), and Potsdam (1945) conferences—Big Three Ally Joseph Stalin of the USSR, was better informed about the war affairs of his US and UK allies than they were about his.[7]
Soviet espionage was at its most successful in collecting scientific and technological intelligence about advances in jet propulsion, radar and encryption, which impressed Moscow, but stealing atomic secrets was the capstone of NKVD espionage against Anglo–American science and technology. To wit, British Manhattan Project team physicist Klaus Fuchs (GRU 1941) was the main agent of the Rosenberg spy ring.[8] In 1944, the New York City residency infiltrated top secret Los Alamos National Laboratory in New Mexico by recruiting Theodore Hall, a 19-year-old Harvard physicist.[9][10]