* It wasn’t until January 1944 that the Australians conclusively broke the Japanese army codes, with the discovery in Cape Huon, in a bomb crater full of water, of a metal box full of Japanese code manuals, says the military historian Lex McAulay. ‘The Japanese had fled into the mountains, and the code man had received a message to destroy all code books. He said he’d done it.’When they dried out the books, the Australians realised their significance, and sent copies to London, Washington and Brisbane. ‘Macarthur just couldn’t ask for anything better,’ said McAulay. It changed the course of the war: the Allies were henceforth able to pre-empt every Japanese intention. Indeed, the invasion of the Philippines was brought forward because of the new capability to read Japanese wires.