In the eyes of history, Japanese intelligence in World War II has fared very poorly. However, these historians have most often concentrated on the later years of the war, when Japan was fighting a multi-front war against numerous opponents. In this groundbreaking new study, Japanese scholar Ken Kotani re-examines the Japanese Intelligence department, beginning with the early phase of the war. He points out that without the intelligence gathered by the Japanese Army and Navy they would have been unable to achieve their long string of victories against the forces of Russia, China, and Great Britain. Notable in these early campaigns were the successful strikes against both Singapore and Pearl Harbor.
Yet as these victories expanded the sphere of Japanese control, they also made it harder for the intelligence services to gather accurate information about their growing list of adversaries. At the battle of Midway in 1942, Japanese intelligence suffered its worst mishap when the Americans broke their code and tricked the Japanese into revealing the target of their attack. It was a mistake from which they would never recover. As the military might of Japan was forced to retreat and her forces deteriorated, so too did her intelligence services.

In the eyes of history, Japanese intelligence in World War II has fared very poorly. However, these historians have most often concentrated on the later years of the war, when Japan was fighting a multi-front war against numerous opponents. In this groundbreaking new study, Japanese scholar Ken Kotani re-examines the Japanese Intelligence department, beginning with the early phase of the war. He points out that without the intelligence gathered by the Japanese Army and Navy they would have been unable to achieve their long string of victories against the forces of Russia, China, and Great Britain. Notable in these early campaigns were the successful strikes against both Singapore and Pearl Harbor.
Yet as these victories expanded the sphere of Japanese control, they also made it harder for the intelligence services to gather accurate information about their growing list of adversaries. At the battle of Midway in 1942, Japanese intelligence suffered its worst mishap when the Americans broke their code and tricked the Japanese into revealing the target of their attack. It was a mistake from which they would never recover. As the military might of Japan was forced to retreat and her forces deteriorated, so too did her intelligence services.