History of Soviet espionage

Coming to power as a clandestine organization, having been schooled in the secret police tactics of the Czarist Okhrana the new Soviet government of the Soviet Union tended to overestimate the degree to which the other European powers of the day, especially the United Kingdom, were plotting its destruction. With that mindset Lenin and his colleagues through the precursor agencies of the KGB, beginning with the Cheka, made serious efforts to obtain information regarding the activities and plans of the European powers, the United Kingdom, Germany, France and Italy.

As the other European powers had only rudimentary intelligence agencies, the Soviet Union soon outstripped them in obtaining information and placing agents within their governments who kept Soviet leaders informed of their military and foreign relations positions and intentions. The United States, perceived as being on the periphery of European affair received little attention until the late 1930s but during the Cold War years, together with the United Kingdom, became the main focus of attention.

Significant successes were had in the United Kingdom with the recruitment of the Cambridge Five, a ring of British spies who passed information to the Soviet Union during World War II, and up until the early 1950s. The five consisted of Kim Philby, Donald Maclean, Guy Burgess, Anthony Blunt, and John Cairncross. In the United States (and in the United Kingdom also) great success was had in the stealing of technological secrets, especially regarding the atom bomb. The State Department was also deeply compromised during the Roosevelt administration at a time the United States had no significant countervailing intelligence capacity within the Soviet Union.

In the late years of the Cold War the KGB was able to recruit moles high within the FBI (Robert Hanssen) and the CIA (Aldrich Ames).

First Chief Directorate
For most of the history of the Soviet Union there were two intelligence agencies, the First Chief (Foreign Intelligence) Directorate (FCD) of the KGB and Soviet Military Intelligence (GRU). From October 1947 to November 1951 these two agencies were briefly merged in a separate foreign intelligence agency (KI).

Codenames
The KGB in its internal communications used a system of codenames for its employees (worknames), for persons supplying information to it, for persons of interest, and for foreign leaders, agencies and locations. Codenames were assigned to a number of persons who were not spies; thus mention of a person, for example, in a message decrypted by the VENONA project does not establish that a person was a spy, only that there was a codename assigned for some purpose.