Admiral Nimitz and the War Against the Navy BureaucracyConverted for the Web from "Battle Of Wits: The Complete Story Of Codebreaking In World War II" by Stephen Budiansky
Jump to: Doolittle's Raiders | Admiral Isoroku Yamamoto
Joseph J. Rochefort | Stealing the Japanese Code | War Against Japan
After Pearl Harbor | A Man with a Mission | War Against Bureaucracy
Ambush the Ambushers | The Battle of Midway
Denouement: Intelligence Vindicated
On March 18, 1942, they caught up at last. The order to begin "current decryption" of JN-25 went out. The war against the Japanese code makers was won. Now the war against the Washington code breakers began.
The odd and ill-defined bureaucratic relationship between Station Hypo and OP-20-G was the stuff that Washington intrigues are made of. Technically Rochefort reported to the commandant of the Fourteenth Naval District in Honolulu, a practical enough man to leave Rochefort to his own devices and let him deal directly with Captain Edwin Layton, the intelligence officer for the Pacific Fleet. But it was OP-20-G that had tapped Rochefort for the job and that loosely coordinated the division of labor among all the various intercept stations. In late January 1942, Commander Safford, Rochefort's old mentor, had been shunted aside in a Byzantine power play at Navy headquarters. Although Washington and Honolulu had established a close collaboration on JN-25, exchanging additive and code groups via a secure radio link that employed the never-to-be-broken SIGABA/Electric Cipher Machine, Rochefort and his new nominal superiors in Washington were on an inescapable collision course. Washington was now demanding central control over all code breaking and intelligence. Safford had been a firm believer in decentralization, and Rochefort insisted he was answerable only to the new Pacific Fleet commander, Admiral Chester W. Nimitz. He was also tactless enough to make it abundantly clear what he thought of Washington's meddling.
The simmering tension broke out into open warfare almost as soon as current reading of JN-25 began. Rochefort had developed a close working relationship with Layton, and the two men would speak by phone several times a day. Layton had come to respect Rochefort's reliability and caution. Both men were fluent in Japanese and Layton knew that Rochefort personally translated more than a hundred of the five hundred to a thousand messages that were being deciphered each day. Knowing that most commanders tended to dismiss intelligence reports as the work of alarmists, and knowing too that Rochefort was never one to exaggerate, Layton routinely upped Rochefort's estimates to compensate for their subsequent discounting. If Rochefort reported four enemy carriers in an area, Layton would change it to six. So when Layton's phone rang on May 14 and he heard Rochefort at the other end of the line exclaiming, "I've got something so hot here it's burning the top of my desk!" he dropped everything and headed right over to the Dungeon. The hot document proved to be a partial decrypt in which the words koryaku butai, invasion force, were followed by the geographical designator AF. Koryaku butai had appeared in orders for the invasions of Rabaul, Java, Sumatra, and Bali that Hypo had already read. AF had been tentatively identified as Midway. Rochefort argued that the clincher was an order that air base equipment was to be shipped to Saipan to be in position for the "AF ground crews." AF was obviously an island air base; it was, Rochefort insisted, a matter of simple deduction to see that it had to be Midway.
Nimitz was quickly convinced. On May 17 he ordered his three remaining aircraft carriers to return at once from the South Pacific. The following day he sent an order to Midway, via secure undersea cable, canceling previous orders to one of the U.S. submarines based there. The new instructions: BELIEVE ENEMY WILL ATTACK MIDWAY USING PLANES LAUNCHED FROM A POSITION FIFTY MILES NORTHWEST OF MIDWAY X PATROL THAT AREA UNTIL FURTHER ORDERS. That same day the Seventh Air Force, at Hawaii, was placed on a special alert; its B-17 bombers were taken off reconnaissance duty and kept loaded with demolition bombs to be ready to carry out strikes against enemy ships on a moment's notice. Other B-17s were moved in from the mainland, and plans were set in motion to fly some to Midway itself.
But then Commander John H. Redman, who had maneuvered himself into the command of OP-20-G in the January reshuffling, began to throw cold water in copious quantities. Washington, in short, rejected Midway as the target of the gathering Japanese offensive. Several weeks earlier Redman had scrawled an irritated note on a memo that had identified AF as Midway: "Comment said AF=Midway, but pointed out that comm. zone designations not identical with area designations."
On May 14, OP-20-G had sent an intelligence summary to Admiral Ernest King, the Navy Commander in Chief in Washington, concluding that the Japanese were preparing a "coordinated air and submarine attack on the Hawaiian Islands." Then OP-20-G insisted that Hypo had bungled its additive tables; the Japanese orders were not to attack AF but rather AG, Johnston Island. On May 16 and May 17 OP-20-G was warning of a second Japanese offensive, this one directed against Alaska and the Aleutian Islands. Some intelligence officials in Washington suspected the whole thing was a Japanese deception operation; the real target might even be the West Coast of the United States. A message intercepted May 19 seemed especially fishy. A Japanese seaplane unit informed the Bureau of Personnel in Tokyo that its "next address" would be Midway, presumably so its mail could be forwarded. As Army Chief of Staff George C. Marshall would later note, that seemed to lay it on just "a little bit too thick."
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Admiral Isoroku Yamamoto
Copyright © 2000 by Stephen Budiansky. All rights reserved. Converted for the Web with the permission of Simon & Schuster.
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