The catastrophe at Pearl Harbor has catalyzed an underground of conspiratorial whispers and Congressional uproars. Was our Pacific outpost betrayed by criminal negligence? Did President Roosevelt himself spur the Japanese attack in order to save his administration from impending doom? The answers to both, according to Roberta Wohlsetter in probably the most massive monograph yet written on the ins-and-outs involved, is a resounding No. Yet while it is clearly established that the military and the cabinet acted in good faith, the disastrous fact remains they did misread the warning signals, did interpret the cryptograms and were caught in the thousand and one cold war crises and contingencies which to this day we have found impossible to resolve. Mrs. Wohlstetter with amazing sang froid sorts out memoirs, private papers, interviews and transcripts (Washington hearings, War Crime Trials, etc.), then illuminates unflaggingly the Honolulu Intelligence organization, the Army and Navy MAGIC code, the East-West diplomatic muddle, Yamamoto's plan, the elements of surprise attack and accidental war, and, most importantly, like a leitmotif invading everything, the built-in ambiguity of bureaucratic action. Certainly a last-word must for all historians and/or strategists.