I finished Ben Macintyre’s book, Operation Mincemeat last week. Operation Mincemeat was the World War II operation carried out by the British Intelligence to deceive the Germans about the planned Allied invasion of Sicily.
Macintyre talks about the top-secret Twenty Committee, which was in charge of the exploitation of double agents (real and fictional), and the suitably named Double Cross System (XX System).
What i found quite extraordinary is this:
“…of the several hundred enemy (German) spies dropped, floated, or smuggled into Britain, all but one was picked up and arrested: the exception was found dead in a bunker after committing suicide. The Germans did not have an intelligence operation in Britain.”
But the Germans did not know that.
Nor did the British know the extent of their success, until after the end of WWII.
The British used this Double Cross System to fool the German Intelligence (Abwehr) into believing they were receiving valuable and reliable information from British double agents, real and fictional. Abwehr even stopped sending more agents after a certain point of the war and became completely reliant on these double agents.
The most famous of whom was Agent Garbo, who established an entire network of 27 fictitious(!) agents who were supposedly providing intelligence to the Germans.
“Garbo’s agents had nothing in common except for the fact that they did not exist”
In fact, Graham Greene based his classic novel Our Man in Havana on Agent Garbo.