Gathering Intelligence Over the Airwaves in WWII
Gathering Intelligence Over the
Airwaves in WWII
Not So Public Radio : A Byte
out of History. Source: FBI, Washington D.C., October 13, 2004.
As far as the war effort went, 1942 was a big year for radio.
The "Voice of America" began broadcasting American-based news of the war
throughout Europe. Armed Forces Radio was launched to boost the morale of
soldiers around the world.
And, on October 9, on a small farm outside Clinton,
Maryland--some 25 miles southeast of the nation's capitol--the FBI launched its
first major radio station.
An FBI radio station? That's right. But it
didn't play the hits of Glenn Miller, Harry James, and other top recording
artists of the day. It covertly monitored and intercepted Nazi radio traffic,
gathering vital bits of intelligence that supported the Allied cause.
We'd actually been using radio monitoring stations to intercept
signals from secret Nazi radio networks for more than a year, including at the
Clinton site. But with enemy radio traffic growing by leaps and bounds (the
Clinton station alone had intercepted nearly a thousand espionage messages by
March 1942), more engineering and personnel firepower were needed.
By October 1942, the revamped station was complete.
A larger complement of FBI radio operators--both men and women--began working
24/7 to intercept any and all enemy transmissions coming from inside and outside
How did the Nazis transmit these messages?
Usually via Morse Code over "covert" Nazi stations discovered by the FBI or
other agencies. Other times by embedding secret messages in popular German radio
Once intercepted, though, the messages were handled the
same way: they were quickly sent via teletype to the FBI Lab, which
analyzed and decoded the intercepts.
It was a two-way street. Beyond picking up
transmissions, our operators also sent messages of their own: to FBI employees
connected via radio networks, of course. But also to Nazi agents. Thinking they
were talking to fellow spies, these agents were actually being used to spread
disinformation. Once, with the help of a German double agent, we sent the Nazis
over 140 bogus messages, many of which were then forwarded to the Japanese
With the success of the Clinton operation, the Bureau
built more radio facilities. By February 1943, our radio circuits
stretched from Juneau, Alaska, to Santiago, Chile, with more than a dozen
stations in between. Ultimately, nearly 30 of these radio stations were
operating in the western hemisphere.
The wartime dividends? Outing many Nazi agents
in the U.S., across South and Central America, and even in Europe; throwing the
Axis powers off course with disinformation; and providing key bits of
intelligence that were shared with the military, the State Department, and some
foreign intelligence agencies.