The April 2003 edition of THE SUBMARINE REVIEW published my article, Missing Magics Machine Material. New insights on December 7, 1941 and Relevance (or Todav ‘s Navv. This article was dedicated to the memory of a great Submariner, Captain Edward Beach, US Navy. Captain Beach was a distinguished author, writing amongst many publications Run Silent, Run Deep. and the authoritative defense of Admiral Kimmel at Pearl Harbor, Scapegoats: A Defense of Kimmel and Short at Pearl Harbor (1995). My article sought to support Captain Beach’s defense thesis by reference to data and issues associated with the Magics Machine that was exchanged by the US Navy for a British Enigma Machine from Bletchley Park. Captain Beach sadly passed away on December 1, 2002 before he could read the final transcript of my article. Readers may recall that I was limited in some key areas because the British had still not released much highly classified material with which I was familiar as a result of work done with my mentor earlier in life, Professor Sir Harry Hinsley, a critical Bletchley Park team member and later Vice Chancellor of Cambridge University. The good news is that the British have since released more data, not all by any means, but data that is very important for supporting Ned Beach’s defense thesis, and also augments my article.
A very fine Australian mathematician at Sydney University, Professor John Mack, assisted by Dr. Peter Donovan, has published an article in the Royal United Service Institution Journal in November, 2012 analyzing the newly released information. What I will do below is to summarize the new data in Professor Mack’s article, and then draw several key conclusions for both the Beach thesis and defense and also how it impacts my original article.
First, the data reveals that the British had made great strides in deciphering and using data from the main Japanese Navy code (IN-25) in 1939-1940, and then joimly with the US in 1941-42. IN-25 was not changed until July, 1944 with a new code (IN- 25N62) that was much more powerful, a code that fortunately was soon replaced by a less capable code. The genius behind the breaking of IN-25 at Bletchley was John Tiltman. Professor Mack’s article provides in considerable detail the mathematical basis for the breaking of JN-25. Key point- the British had broken the critical Japanese naval code before the exchange of the two machines.
The British National Archives house the record of all this and Professor Mack provides the references. What is most revealing is the direct connection between the British Far East Combined Bureau (FECB) in Singapore and Bletchley Park, together with two other pillars of an interconnected highly classified SIGINT consortium, the Australian SIGINT unit in Melbourne and OP-20- G in Washington DC. In June, 1939, for example, the British had already intercepted 920 Imperial Japanese Navy messages within just the first three weeks of operations. From then on a series of new special highly sensitive Codes books were produced by the brilliant team led by John Tiltman at Bletchley, working in close liaison with FECB in Singapore. For reasons Tiltman explains OP- 20-G made decisions that meant that the US Navy Station Cast in the Philippines was the only station working Jn-25. Station Hypo in Hawaii was preoccupied with another high level IJN code.
The next key point is that the British and Americans agreed in early 1941 to share information and collaborate. The Commander of the British Pacific Fleet and the British Director of Naval Intelligence authorized full and total cooperation. The British official data has been coupled with several critical oral histories- proving the great value of oral histories. Professor Mack writes, “By mid 1941 the collaboration between the FECB and Cast was in full operation, with a secure radio link used for transmitting both message intercepts and new information obtained from the code breakers.” This is a critical statement given that we are now five months from December 7, 1941 . Bear in mind too that Bletchley Park at this time was benefiting from the massive technological break-through in computing by Alan Turing at Bletchley Park. Most significant of all- the new data shows that the Japanese did not change the “B” code book of JN-25 after Pearl Harbor- ergo the British were reading the IIN IN-25 “B” code book right up to the attack on Pearl Harbor. March and May of 1942 saw the great victories at the Coral Sea and Midway- both “B” Code book JN-25 derived victories.
What then should we conclude? First of all the Japanese cryptographers, as Professor Mack observes, were incompetent. Bletchley Park and the FECB were all over JN-25. Breaking and reading the B code Book of JN-25 persisted through December 7, 1941 to May 1942 when the Japanese replaced the B code book. Much of the detailed substance has yet to be revealed. In the open archives to date we know that several thousand intercepts had been made by December 7, 1941. More may be released as the years progress. The most important observation is this: Enigma and British derived data based on the Missing Magics Machine was extraordinarily highly compartmented. Enigma data was treated like gold- with access only to a few key military and civilian leaders, in addition to the Bletchley Park, FECB and Double Cross operatives, and within the ranks of the British SIS (Ml6) and Security Service (MIS) just a very small few, with “C” himself controlling access for the chosen few in Ml6. Winston Churchill and Vice Admiral John Godfrey, the Director of Naval Intelligence, treated Enigma as their single greatest warfighting asset. Any form of compromise was regarded as disastrous. It was not until 1974 that the British first even allowed the existence of Enigma to be known by the public, several years after I had worked on data with Sir Harry Hinsley. We know that Prime Minister Churchill will have discussed the data in detail with President Roosevelt. As the clock ticked to denouement on December 7, 1941 Admiral Kimmel remained totally oblivious to all the above- kept totally in the dark. He was not read into the US-UK special programs and had no knowledge even of the existence of Bletchley Park, and the material that Op-20-G controlled. He had deployed his carriers, and his submarines were on patrol- his key assets, together with mine sweepers and airborne patrols. His battleships were in port- his single biggest oversight perhaps. However, as the losses of HMS Prince of Wales and HMS Repulse demonstrated off Malaya to Japanese dive bombers, shortly after the attack on Pear Harbor, battleships were already in large part naval dinosaurs with the exception of their naval gunfire support role. In the case of the Kriegsmarine, as commerce raiders, though all of Admiral Reader’s pocket battleships were destroyed over time by the Royal Navy- it would be the aircraft carrier and the submarine that would carry the day in the Pacific war, together with amphibious assault and the courage and fortitude of the US Marine Corps. The submarine would be the dominant asset, inflicting more damage by far than any other single naval or military asset or force, with the possible exception of the war ending strikes in August 1945. The Commander-in-Chief of the US Pacific Fleet’s critical and subsequent war winning units were at sea on the day of the attack on Pearl Harbor.
The issue has never been whether Admiral Kimmel should have been relieved and replaced by an extraordinarily capable replacement, Admiral Chester Nimitz, to reinvigorate a critical command after a major defeat, but more his personal vilification, summary reduction in rank, and almost drumhead retirement without due process or recognition. Perceived and actual failure in command by a senior Commander is the prerogative of the Commander in Chief, the President of the United States, but not outright dismissal and denigration as a scapegoat when Admiral Kimmel was clearly denied access to critical intelligence.
Captain Edward Beach took the fight to the enemy in the Pacific with great valor and distinction as a young officer, winning ten decorations for gallantry and the Navy Cross, and came through to perform outstanding service in the postwar nuclear submarine Navy. During World War Two he served aboard USS TRIGGER, USS TIRANTE (he was Executive Officer to Captain George Street who was awarded the Congressional Medal of Honor during TIRANTE’s first war patrol), and commanded USS PIPER.
We owe him a great debt for his honorable quest to search out the truth and defend the tarnished reputation of Admiral Kimmel. The above goes a little further to help what Captain Beach wrote. The full and final story has yet to unfold, and perhaps before the 100th anniversary on December 7, 2041 the public records will finally show what was fully known. I may not be here, but I feel sure that Admiral Kimmel will be finally exonerated. Captain Beach would want this.