Funkspiel

Funkspiel (radio play) was the name given to a counter-espionage operation carried out by Nazi counter-intelligence during the Second World War. It consisted of using captured and "turned" (meaning forced to work for the Nazis) clandestine radio operators in France to send false messages back to the enemy (the United Kingdom in particular), and allowed the Nazi services to intercept Allied military information, transmit disinformation to the enemy and to fight resistance movements. So, Nazi counter-intelligence "played" (pretended to be) a resistance movement, with a script for the piece written by the Gestapo or the Abwehr.

The last faked message that the Nazis exchanged with London in this operation was this: "Thank you for your collaboration and for the weapons that you sent us". However, the Nazis did not know that the British intelligence services knew about the Nazi stratagem at least two weeks before this transmission. Thus, if the Nazis had been able to gain certain benefits from the operation, the strategy was later used against them and from May 1944 onwards the operation was no longer a success.

A similar funkspiel, called Operation Scherhorn, was executed by the Soviet NKVD against the Nazi secret services from August 1944 to May 1945.

Funkspiel also referred to a technique of U-boat radio operators who would synchronously vary the frequency transmission knob to confuse any Allied personnel that happened to pick up the same channel.