Rep., 1982. Xv + 332 pp., photo & other plates + 2 maps. D.j., 24 x 16cm. Title on spine of d.j., typically faded ; small owner's label to foot of f.e.p., e.p.'s foxed o/w V.G.+. The story of the contribution made to the Second World War in Europe and North Africa by Ultra, the intelligence derived from the decipherment of the Germans' Enigma-coded signals, is well-known. This book, based on contemporary secret documents only 'recently' released, tells for the first time the story of the immense contribution made by signal intelligence to the war against Japan. This intelligence was of two kinds: the intelligence known as Magic, gathered from the breaking of the Japanese diplomatic signals enciphered on the machine called Purple; and the intelligence derived from the breaking of the Japanese naval and military codes, known to the Americans comprehensively as Ultra. From knowledge about Pearl Harbour to the justification of using the Atom Bomb, this subject begins and ends with controversy. Between these two episodes Magic and Ultra intervened, often decisively, at almost every naval and military struggle in the Pacific.