The Army Security Agency existed from 1945, when it absorbed the
Signal Corps' Radio Intelligence Companies, until 1977, when it
was consolidated with existing military intelligence units under
the new Intelligence & Security Command. In the beginning, the
ASA set up a chain of listening posts around the Soviet Union.
These posts, which performed signals intelligence missions
against the Soviet Union and its satrapies in the Warsaw Pact,
were called field stations. (Later stations targeted other
Communist nations in Asia.) The primary chain of command for the
ASA ran outside the Army's structure to the National Security
Agency; the ASA units were part of the Army only insofar as the
Army supplied trained personnel to the field stations and took
care of their pay, supplies and (occasional) disciplinary
actions. Early in the Cold War, the primary targets of the ASA
were Morse code signals in the AM band, but the tasking later
shifted to voice communications in the FM band, non-voice
signals such as teletype and