THE EMPEROR’S CODES

An account of American and British operations that broke Japanese codes during WWII.

Japan and Germany did not lose the war because of the Allied advantage in numbers and material—all the big turning-point battles occurred early on, when the Allies were outnumbered. It was stupidity that defeated the Axis, and nothing illustrates this better than the story of codebreaking. In 1943, when fighters shot down a transport carrying Admiral Yamamoto, it was publicized as a lucky accident—but, in fact, details of his flight had been broadcast by the Japanese and intercepted. Inferior American forces could not have won the key naval battle of Midway without knowledge of enemy positions given by Japanese transmissions: American submarines devastated Japanese shipping because we knew their routes and positions. Even Pearl Harbor came as a shock not through poor codebreaking, but because US intelligence concentrated on reading the Japanese diplomatic (rather than military) code. We knew their diplomats negotiating in Washington were not serious and that Japan was about to launch a war, but the details were elsewhere. British journalist Smith (Station X, not reviewed) includes a fascinating step-by-step explanation of codebreaking, but most readers will probably not be able to follow beyond the first steps. Because of their difficult language and sense of intellectual superiority, the Japanese assumed their codes were unbreakable—but they were merely difficult. The codebreakers themselves were a collection of academics, geniuses, and eccentrics assisted by a vast army of clerks (including many women). There were also plenty of small-minded bureaucrats and arrogant (mostly American) officials unwilling to share information, so progress was often unnecessarily slow.

A fine contribution to the genre: The author has done his homework well, interviewing survivors and poring over old records to tell the story of one of the greatest capers of the century.