The Double Agent Who Won D-Day

IN The Art of War, Sun Tzu says that of the five classes of spies the most important is the “converted spy,” or double agent, because it is only through him (or her) that true “knowledge of the enemy” can be obtained. John le Carré writes that in Tinker, Tailor, Soldier, Spy—perhaps the greatest literary representation of a counterespionage operation—he wanted to capture “the sheer scale of the mayhem that can be visited on an enemy service when its intelligence-gathering efforts fall under the control of its opponent.” Few individuals without rank or office can be more pivotal in warfare than a well-placed operative who has pledged loyalty to one side but secretly serves the other. In his dramatic and entertaining new book, Stephan Talty shows how a single Spaniard, pretending to work for Nazi Germany while actually serving British intelligence, was “the linchpin” of the successful deception campaign to convince Hitler that the D-Day landing at Normandy was merely a feint for a larger arrival in Pas de Calais, a move that allowed the Allied armies to gain the foothold necessary to open up a Western Front and commence the ground war that would help end the Third Reich.