Abstract

The importance of Signals Intelligence during the Second World War has long been established. For the period of the Cold War, however, it is curiously absent from the current historiography. Thanks to recent declassification we now know that the British Signals Intelligence Agency GCHQ was intercepting a large number of police a…nd state security communications in Eastern Europe after 1945. They demonstrate the extent to which the British government was informed in detail about the Stalinization of the region.

This paper will analyse this material and argue that the intelligence it provided had a significant impact on the development of domestic policy in the field of counter-subversion. Specifically, the way the British government and intelligence community perceived and countered the Communist threat to national security was shaped considerably by the experience of the Communist take-over of Eastern Europe.