Page:CIAdeceptionMaximsFactFolklore 1980.pdf/42

C00036554 A scheme to ensure accurate feedback increases the chance of success in deception.

The above principle is logically virtually self-evident. Such an idea has evolved independently in many disciplines. It pervades most of control theory, has a counterpart termed "the value of perfect information" in decision theory, and is a central idea in the theory of games (particularly extended games). As "Comebacks" it is jargon of the a British contribution to the espionage/covert action trade (49).

Perhaps the most dramatic example of the role of feedback in wartime deception was the intelligence provided by ULTRA, the top secret espionage and cryptographic breakthrough that enabled the British to read the German Codes. In the view of many, ULTRA information was a key element in the success of the Allied invasion of Normandy. As Lewin (SO) remarked:

"[Colonel .John] Bevan, head of LCS, and [Lt.-Col.T.A.] Robertson, head of BIa section of MIS, have jointly testified to the author that without ULTRA the great web of deception spun round the Germans could never have been devised. Yet without their efforts, OVERLORD might have been a disaster." (Emphasis added.)

Even at the simplest operational level, feedback