Islands of Destiny: The Solomons Campaign and the Eclipse of the Rising Sun (40 page)

By then it was too late anyway. The New Zealand corvette
Moa
had nosed around the wreck the morning after the battle. By some accounts codebooks were taken then. On February 11, Army G-2 officers went to the site aboard
PT-65
and discovered much intelligence to exploit. Submarine rescue vessel
Ortolan
returned on the thirteenth, and divers salvaged documents including five codebooks, which were delivered to the Cactus Crystal Ball. Phil Jacobsen remembers the red-bound books, weighted with lead to be thrown overboard if necessary, and how the signals intelligence
people worked to restore the waterlogged pages. Clean sheets of dry paper were placed between each leaf and the codebooks put on a hot radio receiver whose vacuum tubes did the job. On February 15, Cactus naval base reported acquiring seven codebooks, including two in the JN-25 code. CINCPAC immediately instructed the South Pacific command to forward the material by aircraft as quickly as possible.

Some historians have objected to an estimate in a history of Japanese naval communications that the
I-1
disaster resulted in the loss of 200,000 codebooks. This is a misinterpretation. The number refers to the copies of various code publications throughout the Imperial Navy that
had to be replaced
as a result of the compromise, not to the books actually lost in the submarine. Others have minimized the importance of the windfall, arguing that the current version of the code had actually been destroyed. That observation fails to take into account how codebreaking worked. JN-25 was a “book code” of groups of letters that stand in for words—and there were thousands of words in the Imperial Navy’s fleet code. Until the
I-1
incident, Allied codebreakers never even knew what all the words were, did not know how the Japanese rendered certain technical terms, and remained free to dispute meanings. Even an old codebook settled those matters. Commander Thomas Dyer, codebreaker extraordinaire at Pearl Harbor, would later comment, “It was very useful to have a complete code, fleet vocabulary. It settled a number of arguments.” Suddenly the codebreakers had a panoramic view of JN-25’s structure.

In addition, the
I-1
yielded lists of the Imperial Navy’s geographic designators, radio call signs, short-time and area codes, and a wealth of technical data on Japanese subs. A petty officer rescued from the crew furnished supplementary detail. Equally important,
the Japanese
considered the loss an intelligence crisis of the first order. The Imperial Navy immediately declared a cryptologic emergency, changed the additive tables used with JN-25, and began compiling a new codebook with different values. But they did not change the basic codebook. After the
I-1
, Allied codebreakers were two steps ahead on JN-25 throughout the war.

The Guadalcanal intelligence bonanza burst upon an Allied intelligence community morphing into new configurations. In the works for months,
these changes created an even more dominant juggernaut. Some changes resulted from sincere efforts to improve the information that underlay operations, some from personality clashes; others could be traced to officers jockeying for position. Several strands of this story began and evolved through the first year of the war, but they came together early in 1943.

On the technology side there were two key developments. One resided in the increasing use of punch cards and mechanical sorting devices. The basic work of penetrating JN-25 and the other Japanese codes was accomplished by hand. Progress remained dependent on the ability to cross-reference possible discoveries, and there the card sorters proved critically important in accelerating the pace. The machines were not new, but the war brought great numbers of the sorters into service, and that injected fresh vigor and speed. “Radio Fingerprinting” (RFP)
was
a new development. It had long been recognized that experienced radiomen became so familiar with the circuits they monitored that, much like handwriting, over time they could recognize the “hand” of a given Japanese operator. The RFP technique capitalized on this phenomenon and regularized the process. An oscilloscope would be connected to the radio receiver, and whenever monitors overheard a new enemy operator, oscilloscope photos would be taken of his transmission, identifying his method and “hand.” Over time intelligence accumulated an extensive file of these “fingerprints,” which helped radio traffic analysts follow changes in the Japanese system. RFP helped identify the key enemy messages—which would be given to the most trusted operators for transmission—and it could reveal the character of a given ship or unit or even its identity when call signs were not available.

The most important organizational change concerned merging different pillars of intelligence to produce “all source” data. When the Central Intelligence Agency in the 1990s trumpeted so-called “fusion centers,” it was really reviving this concept from World War II in the Pacific. Not long after Pearl Harbor, Washington began considering fusion centers, and soon after that the Marine Corps commandant suggested these be created in the field, starting with Pearl Harbor. A Washington delegation went to Hawaii to talk up the fusion concept, its Navy representative Commander Arthur H. McCallum, longtime chief of the Japan desk at the Office of Naval Intelligence. McCallum knew everybody in intel, but not Admiral Nimitz, and he was also afraid to broach the subject with Captain Edwin Layton,
CINCPAC’s fleet intelligence officer, who might feel threatened by a joint center. McCallum was right about Layton, but that turned out not to matter. Shortly before Midway, Chester Nimitz put his name to a paper accepting the concept. A week after that battle, Admiral Ernest J. King approved the creation of an intelligence center. Layton, meanwhile, was wrong about the bureaucratic threat—his job with CINCPAC was secure so long as he wanted it.

Admiral Nimitz was notorious on the subject of staffs—none could be small enough for him. When Commander McCallum first broached the intelligence center with CINCPAC, Nimitz laughed as the emissary suggested a unit of 120 people. He couldn’t fit that many on his flagship, Nimitz countered. But the realities of command across the Pacific soon forced the admiral to move CINCPAC headquarters ashore, and size became less problematic. In July 1942, seventy-six officers and men were ordered to Pearl Harbor to create the Intelligence Center Pacific Ocean Area (ICPOA), which grew like Topsy. The center absorbed Commander Jasper Holmes’s combat intelligence unit, then an Army map unit, then newly trained language officers to interrogate prisoners, and later Pearl’s photographic interpretation group. Station Hypo, reconstituted as FRUPAC, worked alongside ICPOA. At a December 1942 conference with Nimitz, despite his opposition Admiral King affirmed the decision to expand the center and have the radio spies report to it. In September 1943 the fusion took final shape, becoming the Joint Intelligence Center Pacific Ocean Area under an Army brigadier general. By war’s end 1,700 people worked there, and Admiral Nimitz appreciated every single one of them.

The codebreaking group mushroomed too, even with the transfer to ICPOA of Commander Holmes’s unit, by then a virtual FRUPAC ancillary. At the time of Midway there had been 168 persons—including radio operators—in the Station Hypo codebreaking unit, with just two cryptanalysts and three traffic analysis experts. By Eastern Solomons, FRUPAC had grown to 283 people, among them fifty-four experts in the code or traffic work or in the Japanese language, plus forty-six additional radio intercept operators in training. The Navy soon ordered FRUPAC personnel increased to 500, with seventeen more code experts and twenty-four extra language officers. Having outgrown its quarters, in early 1943 FRUPAC moved to a huge new wood frame building near CINCPAC headquarters on
Makalapa Hill. The Intelligence Center moved with it. Construction mirrored the burgeoning expansion: Before the end of the war FRUPAC had taken over the entire building, and an identical one had been built next door for the Joint Intelligence Center, which would also have an advanced echelon on a captured Central Pacific island. By then the U.S. Navy alone was operating 775 receivers across the Pacific entirely devoted to intercepting Japanese message traffic.

One man who did not make the move was Commander Joseph J. Rochefort, FRUPAC’s eccentric chief. Until the fall of 1942, Rochefort had personally handled every Ultra decrypt at Pearl Harbor. Smoking his pipe, sitting at his desk in a bathrobe, Rochefort had penciled code solutions on pads used for that purpose. In a way, what happened was a harbinger of codebreaking come of age: The exponential growth of the effort, the increasing numbers of messages in the system—tokens of Ultra success—forced a mass-production approach. Joe Rochefort was an icon of a past age, when the gentleman codebreaker held sway. But he was also a victim of envy and ambition.

The codebreakers’ head office in Washington—Station Negat in the cable addresses and Op-20-G by its Navy Department title—was headed by Captain John R. Redman and seconded by Commander Joseph N. Wenger. Redman, a communications expert, went to CINCPAC in the fall of 1942, leaving Wenger, promoted to captain, in charge. They denied Rochefort the award of the Distinguished Service Medal after Midway. Captain Wenger disliked the Hypo chief and hated the way Rochefort ignored Op-20-G directives. But Hypo had been right about Midway and Op-20-G wrong, and Rochefort saw no reason why FRUPAC should abandon work on key codes of which it had the deepest knowledge just because Wenger wanted the glory for Negat. Rochefort got Admiral Nimitz to approve a cable stating that FRUPAC worked only for CINCPAC, and only through him for Washington. Captain Layton also believed that Op-20-G harbored unduly alarmist fears of Japanese masterstrokes and counseled Nimitz to listen to Rochefort. Thus Nimitz protected Rochefort, untouchable after Midway.

Captains Redman and Wenger had the ear of Admiral King. Op-20-G officials saw the COMINCH almost every day. Over time Wenger convinced Ernie King the FRUPAC chief was a disruptive influence. At any rate, King got sick of the backbiting. If Rochefort had to be sacrificed to promote
comity, those were the fortunes of war. With the reorganization going on perhaps Rochefort’s departure would be more understandable. In October 1942, Admiral King summoned Commander Rochefort to Washington on temporary duty. He ended up as skipper of a floating dry dock. Jasper Holmes recorded that Rochefort “became the victim of a Navy Department internal political coup.” Commander William B. Goggins succeeded him at the head of FRUPAC. His deputy would be Jasper Holmes. In later years Negat partisans claimed that 75 percent of the biggest breaks had happened there. FRUPAC veterans insist that 80 percent of the significant breakthroughs were made at Pearl Harbor.

Behind the scenes of the codebreakers’ secret war, another conflict raged between the Office of Naval Communications and Office of Naval Intelligence (ONI) over control of the Ultra empire. John Redman’s brother Joseph, already a rear admiral, was director of naval communications. Admiral Redman coveted Op-20-G and wanted Ultra for himself. Others maintained that Negat’s function was intelligence and it should be within the ONI bailiwick. This dispute triggered continuing friction and reduced effectiveness to a degree, but since it continued past our period here, it will be noted only as a persistent problem.

As contentious as were issues between Washington and Pearl Harbor, those in General MacArthur’s command were equally thorny. MacArthur wanted primacy for his SOWESPAC G-2 staff, yet he had to contend with the Australian government, with its own intelligence services, including such special services as the coastwatchers, a Dutch special services unit, and support to guerrilla forces in the Philippines. The organizations multiplied. SOWESPAC created an Allied Translator and Interpreter Section, which specialized in reporting on captured Japanese documents, and incidentally became a major employer of Japanese-American Nisei. Also established in 1942 was the Allied Intelligence Bureau, which handled special warfare activities like support to the Filipino partisans. Commander Feldt’s coastwatcher organization Ferdinand became Section C of the Bureau. SOWESPAC also served as locus for another intelligence fusion center, the Seventh Fleet Intelligence Center (SEFIC), up and running by 1943 under Captain Arthur McCallum. Meanwhile, the Australian government’s
codebreaking unit, the Central Bureau, became yet another part of this constellation. And, of course, there was Fleet Radio Unit Melbourne (FRUMEL), officially existing since March 12, 1942.

Under Major General Charles A. Willoughby, G-2 was an Army shop, and that brought trouble with the naval codebreakers of FRUMEL. Lieutenant Commander Rudolph Fabian, its chief, crossed swords with Willoughby on numerous occasions. With Ultra, Fabian’s practice was to relate the information in decrypts but not permit access to the documents except to the top commander, General MacArthur. On one occasion, when Willoughby demanded to see a dispatch, Fabian carried a copy to the G-2’s office, took out his cigarette lighter, and burned it in front of the enraged general.

Security was a top worry for Fabian. At the time of Coral Sea, Fabian had briefed MacArthur—as he did daily—and found the general unconvinced when the FRUMEL expert informed him that the Japanese were really going to go for Port Moresby. That did not surprise Fabian much—His own notion of the enemy strategy had been that they would go for New Caledonia first, to isolate Australia. Commander Fabian launched into an explanation of the entire Ultra process, and the SOWESPAC boss ended up diverting a transport scheduled for New Caledonia to Port Moresby instead. General MacArthur seemed so excited, the Navy officer worried the SOWESPAC leader would reveal his source. Meanwhile, British codebreakers laboring as part of the Allied common effort complained that Fabian and FRUMEL were denying them appropriate access. On the Australian side, Commander Eric Nave was a big player in Royal Australian Navy codebreaking and came aboard at FRUMEL. Fabian repeatedly upbraided Nave for lax security discipline until the latter left for the Central Bureau. Commander Fabian felt relieved to see him go.