Fertile subject, muzzy treatment. Deacon has written histories of the British, Russian, Chinese, and Israeli secret services: along the way, he came across Japanese espionage activities, and he's looked up references. He also has a few ideas to put forth. But, like just about everyone else, he doesn't really know much about the organization or operation of Japan's secret services at any given time. The term Kempei Tai means military police; their function in pre-WW II Japan was internal intelligence, anti-subversion, and, most notoriously (though Deacon doesn't quite say so), repression. The Army and Navy also had intelligence services. Secret societies engaged in foreign espionage. Army and Navy officers gathered intelligence. So did Japanese abroad. And thus we come to what Deacon, who can't sort all this out, does have to say: the Japanese, inherently curious, have ""a far broader, more imaginative concept of Intelligence"" than any other people; intensely patriotic too, they were willing to assume even lowly disguises to gather information. In short, anyone and everyone spied. And, under the rubric of Kempei Tai, Deacon cheers--it makes the Japanese more peaceable (i.e., they'd rather win without fighting). The content, then, consists of disparate examples of Japanese spying from the 16th century to the present--the early and late ones strained to fit. Historically, Toyotomi Hideyoshi (""The Spymaster Who Unified a Nation"") was a clever warlord/diplomat; Will Adams (""The Agent from England"") was the first Englishman to reach Japan, and a source of information. As of the last 25 or 30 years, Deacon makes the interesting assertion that the Japanese systematically substituted economic for military intelligence--not only to benefit Japan but to find ""new work for intelligence-gatherers."" In between--for the 1900-1945 period of traditional espionage--we have: intimations of how clerk-spies, shopkeeper-spies, prostitute-spies, etc. contributed to Japanese victory over Russia; sketchy data on Japanese support for Sun Yat-Sen (and, later, other revolutionaries), some of it initially sincere; word of Japan's role in the murky plot to rescue the Czar; intermittent bits on cryptography (Americans were good at code-breaking, Japanese excelled at interpretation); praise for a Japanese scheme to resettle refugee Jews in Manchuria; and accounts of a few concrete Japanese espionage activities in and around the US (a snafu, reported in Time in 1941; the Pearl Harbor coup) and in Southeast Asia (impressively, how the Japanese learned more about Singapore's defenses--or non-defenses--than the British knew). Otherwise: short on facts, and very long on speculation, supposition, and controversial opinion.