Double Agent: The First Hero of World War II and How the FBI Outwitted and Destroyed a Nazi Spy Ring

Journalist Duffy (The Killing of Major Denis Mahon) recounts the first U.S. counterespionage success of WWII: the breaking of a German spy ring centered in New York. It combined “ideologues, opportunists, dupes, adventurers” and a core of agents who initially had a virtual free hand despite F.D.R.’s commitment to sustaining civil liberties. Under Republican pressure, the FBI was made responsible for internal security, and J. Edgar Hoover’s organization demonstrated a high learning curve—thanks in good part to double agent William Sebold. In 1939, Sebold, a German-born naturalized American, was approached by German intelligence, which provided him with elementary training in photography and coding. Returning to the U.S., Sebold contacted the FBI, who in turn offered observation and recording facilities. Sebold proved himself “an actor of consummate skill” in high-risk situations, and when the snare was sprung, 33 spies were arrested, 19 convicted, and the spine of Nazi espionage in the U.S. permanently broken. Hoover was lauded for his handling of the case while Sebold worked in defense plants before sinking back into obscurity. While Duffy’s digressions are distracting and Sebold’s character doesn’t quite hold the narrative together, this remains “one of the great spy missions of American history.” (Aug.)