The Foreign Broadcast Information Service (FBIS) vacuumed the airwaves for opensource broadcast intelligence. During the Vietnam War, the enormous amount of information collected helped in understanding the propaganda war conducted by the South and North Vietnamese, and their allies. Rarely accessed as a source, The Psychological War for Vietnam, 1960-1968 relies heavily on this data to tell the story of the psychological war for Vietnam.

Example FBIS Transcript

Radio Hanoi report on John McCain capture.