Deciphering enemy secrets
contribute consistently and constructively to the Allied signals interception and decoding effort from 1942 to 1945, deciphering messages and analysing Japanese military strategy and movements.
Japan’s deluded war aims opened the door to precisely this manner of cryptanalysis. Japan was determined to dominate the Asia-Pacific war zones from the Aleutians to the Andamans. To communicate with its far-flung armies and navies, Tokyo relied heavily on coded radio signals. And as with grand admiral Karl Doenitz’s communications with his U-boat commanders in the North Atlantic, Allied codebreakers meticulously reconstructed messages and broke open the codes.
And like their German allies, confident that Enigma was unbreakable, Japan relied on the complexity of its changing Kana syllable clusters, its codebooks and the ambiguities of its language to prevent deciphering. The Japanese gambled mightily and lost badly.
Among the outstanding Allied codebreakers was commander Eric Nave of the RAN, who had spent years in British service in Hong Kong and Singapore. Having broken J19, the Japanese diplomatic code, it was Nave who deciphered the “Winds” message to Japanese embassies on what must be done in the wake of an outbreak of hostilities. The final warning from Tokyo was to be incorporated in a weather report.
The Australian contribution to signals intelligence — with intercept stations from Park Orchards outside Melbourne through to Townsville — along with naval analysis at FRUMEL (Fleet Radio Unit Melbourne) and the Central Bureau for the army and air force, was constantly subject to the tensions and tides of Allied co-operation.
The Americans had arrived in Australia in strength after the fall of Corregidor in The Philippines. Indeed, Collie’s chapter on Corregidor is the highlight of the book. It is possible to sense the heat and perspiration, under bombardment, of the confined spaces in the Malinta Tunnel.
However, some among the Allied codebreakers seemed to spend as much time warring with their own side as concentrating on the fight against the Japanese. Collie sheds new light on the Australian war effort, moving steadily yet missing little of significance in the Pacific, from Lae to Leyte.
There are lighter moments, as in Collies’ references to artist Donald Friend’s war, from backbreaking labour on the Brisbane docks to codebreaking.
Collie notes acidly that unless Alan Turing or Bletchley Park appear in the story, Allied codebreakers are routinely denied honour and recognition.
Perhaps, but Code Breakers wards filling this void. travels far to- is a visiting fellow at the US Studies Centre at the University of Sydney.