In an age of dime-a-dozen spy thrillers, it’s easy to forget the historic impact that real-life espionage can have. Take Operation Fortitude, the MI5 plot that effectively misled the Nazis into prepping for Allied attacks at Calais and Norway instead of Normandy in 1944 (and into postponing the dispatch of German troops to Normandy once the invasion began). As British historian Ben Macintyre relates in Double Cross, Fortitude was the work of some smart but eccentric British intelligence officers and a ragtag band of double agents who seem to have sprung from the cast of a particularly silly European farce. These London-based recruits included a fast-talking Polish ex–fighter pilot, a BMW-driving Serbian playboy, a bisexual Peruvian party girl, a chicken-farming Spaniard given to outrageous flights of fancy, and a temperamental Frenchwoman who nearly sabotaged the whole operation out of pique after the Allies lost her beloved terrier-poodle mix, Babs.
As in his earlier best-sellers about WWII-era spycraft, Agent Zigzag and Operation Mincemeat, Macintyre writes with novelistic flair (MI6 assistant chief Claude Dansey had ”a bristling white mustache and the eyes of a hyperactive ferret”). He clearly relishes the quirkier aspects of his story, like an elaborate plan to introduce double-agent carrier pigeons into the enemy’s lofts. But Macintyre never loses sight of the main plot — and British intelligence’s remarkable triumph in building a grand deception that boosted the success of D-Day. Not only did MI5 control every single agent the Germans thought they had working in England, but the agency managed another bureaucratic coup: collecting all the payments sent to the enemy’s vast network of supposed spies. Yes, the Nazis helped underwrite the operation that led to their undoing. A-