The American Magic; Codes, Ciphers and the Defeat of Japan

xv, [3], 332 pages. Footnotes. Illustrations. Maps. Appendices. Bibliography. Index. American intelligence had succeeded, even before Pearl Harbor, in penetrating the Japanese codes. George Ronald Lewin CBE (11 October 1914 6 January 1984), later known as Ronald Lewin, was a British officer, publishing editor, radio producer and military historian. Lewin did not begin writing books until the age of 54. He wrote ten books during his lifetime and was working on a one-volume history of World War II at the time of his death. His best-known book was Ultra Goes to War, an account of the cipher breaking by which the Allies intercepted and broke the coded messages that the Germans transmitted by radio during WWII. His work on Ultra was the first to be based on official documents of the intelligence operation. Historian Max Hastings said of Lewis, "He quickly established a reputation as one of the major military writers of his generation." Derived from a Kirkus review: Now it can also be told. Victory in the Pacific owed as much to deciphered Japanese Magic (diplomatic) and Ultra (military) messages as the European victory did to deciphered German Ultra signals. Lewis has of course utilized newly-declassified materials, including the actual decrypts--importantly supplemented, however, by information from "private sources." The known is amplified, often amended; the previously unknown is entered in. Thus, the first chapter brings, in fresh, dramatic detail, General Marshall's appeal to presidential-candidate Dewey not to reveal American success (before Pearl Harbor) in deciphering Japanese signals. The second spells out just how, from 1921 to 1940, those "impenetrable" Japanese Foreign Office codes and ciphers were cracked. Lewin has no patience with the "conspiracy theory" that FDR deliberately suppressed information to precipitate an attack; the illogic aside, he quotes a "remarkable document" setting out the Japanese decision "to open hostilities in December." But stiff American policy (the scrap-iron ban, etc.) reflected high-level knowledge, from Magic intercepts, that Japanese peace talk was hollow. So: should the Magic intercepts, "properly handled," have revealed Pearl Harbor as the site of the expected attack? Lewin, answering this persistent question with a firm no, persuasively cites Japanese indecision, the mass of contradictory material. Once into the war, the tale becomes one of decrypting feats and decrypt-assisted triumphs which were also threatened, the while, by "extreme" American freedom-of-information and curtailed by egotist MacArthur. The winding-down of the war brings still another controversial matter to the fore: the considerable part that knowledge of Russian intentions may have played in the decision to drop the Bomb. From first to last, a fascinating account of tremendous import. …