Attack on Pearl Harbor (6 page)

Damaged ships could get some help from a few tenders or an itinerant repair ship, but the Japanese did not have forward-deployed mobile dry docks. Ships with underwater damage had to go either to Singapore, back to the home islands, or (for some smaller ships) to captured American facilities in the Philippines. Ships damaged and not seaworthy enough to transit to one of these facilities were essentially lost for the duration—as the war progressed, scores of damaged warships and particularly merchantmen were anchored on whatever odd harbor they could reach, and there abandoned.

The Japanese inventory of forward-deployable repair ships was miniscule.
Akashi
was the only purpose-built repair ship in the fleet; she was joined by
Asahi
, converted in 1938 from a pre-dreadnought battleship, and
Yamabiko Maru
, converted from a 7,000-ton passenger steamer in 1941. Two other small ships added some repair capability.
Matsue Maru
, a 5,644-ton cargo ship, was converted into a “Specially Installed Construction Warship” in April of 1941, and
Urakami Maru
, a 4,317-ton cargo ship, was converted into a “Salvage and Repair Ship” in January of 1942.
⁵⁹
These ships helped with maintenance and repair, but mostly they tried to make damaged ships sufficiently seaworthy to transit to a shoreside repair facility.

Other forward bases, the “unsinkable aircraft carriers” and “unsinkable submarine tenders,” were similarly neglected prior to 1937. When given a choice between spending money on new warships or on forward bases, the Japanese placed a priority on warships. And, according to the treaties awarding control of the Mandate Islands to Japan, the islands were not to be fortified.

Even today the Japanese like to believe that the islands were unfortified. Agawa relates a story from 1937 where the American naval attaché in Tokyo sought permission to visit the Mandates but was refused, “not that [the IJN] did not want him to see installations being built in that area, but that it was afraid he might find out that there were no decent military installations at all; it wanted to leave him with the impression that some did, in fact, exist.”
⁶⁰

However, this is disingenuous.

The islands in question were Class “C” Mandated Islands under the League of Nations, where the occupying nation administered the territory under its own laws, in this case as if the islands were part of Japan. They were not allowed to fortify the islands.

However, Japan withdrew from the League of Nations without returning the Mandates, and from 1937 they ignored restrictions on military development. Japan publicly insisted that it was not fortifying the islands; however, there was brisk development of ports and airfields and associated facilities for “economic development,” facilities that certainly would have dual-use military applications in wartime. The exact extent of the development was difficult for outsiders to determine, since Japan discouraged travel to the islands, controlled entry rigorously, and guarded the sea approaches. Shipwrecked mariners were confined, closely guarded, and removed from the islands promptly. Westerners referred to them as “Japan’s Islands of Mystery.”

By June 1941, $28 million (equivalent to nearly $1 billion in 2009 dollars) had been expended throughout the Mandates, including $7 million ($250 million) on Saipan, Tinian, and Pagan in the Marianas. Facilities included airfields on Kwajalein in the Marshall Islands, Saipan in the Marianas, and Truk, along with port facilities such as piers, warehouses, and workshops. In 1939–40 seaplane tenders
Chitose
,
Kamoi
, and
Kinugasa Maru
carried construction crews and technicians to build seaplane ramps at Truk, Palau, Kwajalein, and Saipan. The tenders made several round trips to Japan to obtain additional construction supplies.

The Japanese insisted that these facilities were built for economic development. However, over the years, it was apparent that the authority controlling the location and design of coastal and island facilities shifted from civilians to the Japanese Navy. When examining the plans for such facilities as Aslito Airfield on Saipan (begun in 1934), it was found that most buildings were constructed to be bombproof and designed for easy conversion into military use, such as a facility for the assembly of aerial torpedoes. Many of these airfields, such as those on Saipan and Kwajalein, were used to launch air strikes in the opening hours of the war. The seaplane ramps facilitated operations of long-range Japanese reconnaissance flying boats such as the H8K Mavis.

While the Japanese limited development of fleet support bases, they did develop outlying islands to support offensive operations by bombers, reconnaissance planes, and submarines. In the context of the original Japanese strategy, overseas bases designed for the long-term forward sustainment and repair of the fleet would not be necessary. The war was supposed to be short, so it would be unlikely that seriously damaged warships could be repaired in time to participate in further actions. The decisive battle would be close to the Empire, so forward bases might be expected to fall to the enemy in the course of the Fabian retreat or be bypassed and isolated, so even the offensive base development was limited to the bare necessities. All that would be needed in the way of forward bases would be limited facilities to service reconnaissance seaplanes, medium bombers, and submarines. For the fleet, all that would be needed would be facilities in home waters.

This strategy was exploded when it was decided to invade and hold the forward resource areas in the Greater East Asia Co-Prosperity Sphere. Now, the Navy was being asked to take
and hold
islands thousands of miles from Japan. Under these new circumstances, the other primary reason for minimizing development of remote bases came to the fore: lack of resources, coupled with a lack of priority.

The Japanese economy was under a severe strain. They had been at war with China since 1931. Japan was smaller than the United States, in land, population, and resources. Remarkably, Japan had nearly matched US military expenditures during the interwar years with an economy no more than 15% as large. However, there was little remaining slack in the economy, and few civilian production facilities left to convert to war production. The competition for resources with the Army meant that the Navy could not have everything it needed. “The IJN was hard into the stops on the nation’s total steel supply,” critical for ammunition and ship production.
⁶¹

Under those circumstances, and in accordance with their national psychology, the Japanese chose to invest in the means to attack rather than the means to defend and sustain. This makes sense on a superficial level: if the forces created to empower the attack did not succeed, any infrastructure of stores or facilities on remote bases could not reverse a setback in the Final Decisive Battle.

This logic holds only if the enemy fights the type of war that you expect, that you want him to fight. If the enemy should operate otherwise, choosing to exploit Japan’s weaknesses rather than confront its strength, then the strategy is exploded, and what was a minor weakness becomes a major handicap.

The operation to invade Midway reflected Yamamoto’s attempt to defeat the Americans’ will to fight on his terms, with Japan on the offensive. It was to force the Americans into a decisive, morale-busting battle before the flood of new U.S. construction made the force ratios impossible. Instead, the loss of four Japanese fleet carriers made a shambles of Japanese pre-war strategies.

With the defeat at Midway the Japanese became reactionary, waiting to oppose an American fleet that they expected to concentrate into one large mass, a reversion to
Zengen Sakusen
. Instead, the war became a struggle of attrition on the fringes, a war of outposts, of cruisers and destroyers and submarines and carrier raids devoid of the massive Jutland-style fleet confrontation upon which the Japanese hopes were centered. Losses were nearly equal, losses which the Americans could replace but the Japanese could not.

Eventually, after the predicted massive American reinforcements arrived, the U.S. fleets concentrated and offered the prospect of a decisive battle, but with force ratios that the Japanese had little hope of overcoming—especially after the cruisers, destroyers, and aircraft that they had built to execute Interceptive Operations and bleed the American fleet had themselves been bled white in the war of outposts. The Marianas and Leyte became American-instigated Decisive Battles on American terms, after irreparable attrition to the Japanese forces on the periphery of the Co-Prosperity Sphere.

The lack of forward fortifications concerned the Japanese from the outset. An American move to take the Marshalls early in the war would both threaten the flank of the Japanese drive south as well as create an early breach in Japan’s planned outer defensive arc. The Japanese felt that the Marshalls were not fortified sufficiently to thwart such a move. This was one of the considerations that argued for an initial strike against the American fleet at Pearl Harbor.
⁶²

Given the attitudes that resulted in minimalist facilities, it is not surprising that the Japanese had not considered the possibility that the destruction of port facilities or fuel transportation and storage might immobilize the American Pacific Fleet at Pearl Harbor better than a strike against fleet units. Again there was mirror-imaging in their thinking, expecting the Americans to act as they would have acted. They ignored—or were not aware of—American logistics vulnerabilities, a concern they could have discovered from open-source publications such as Thorpe’s
Pure Logistics
.
Pure Logistics
featured an example problem calculating logistics requirements for a “Blue” [US] fleet of 20 dreadnoughts and 20 pre-dreadnoughts crossing a 5,000 nm ocean, with Blue having a mid-ocean base located at just about the same distance from the enemy as Hawaii.

The Japanese concentrated on destruction of the Pacific Fleet’s warships, a logical approach particularly if they were aware of the CNO’s dictum that a major offensive into the western Pacific would not be conducted until superior US forces were available. However, even with a successful strike at Pearl Harbor, the Japanese could not expect to reduce the American fleet (or, indeed, the Allied fleet, as they were to initiate hostilities with Great Britain and Holland as well the United States) to a combat power less than that of the Japanese fleet.

The objective of the attack was both material and psychological. The damage inflicted on the enemy was to support the territorial objectives of the war, and to inflict such losses was to establish the psychological state needed to allow the Japanese to win the ultimate victory at peace negotiations.
⁶³

Contradictory Strategies

Yamamoto’s strategy had a significant consequence that historians have not previously recognized. The attack on Pearl Harbor by its very nature made Japan’s overall concept for winning the war OBE. For
Zengen Sakusen
to succeed, the American fleet had to thrust west early in the war, before it was reinforced to overwhelming strength. And yet, the Pearl Harbor attack was to immobilize the American fleet for six months. These goals contradict.

With a six-month delay imposed upon the Americans, there was nothing to prevent them from waiting an additional six months when the arrival of newly constructed ships would give them the means to establish absolute material superiority. The Japanese concocted a narrative where an enraged American people would supposedly demand rapid revenge for the loss of the Philippines, forcing the fleet to move before it was reinforced. At the same time, the Japanese expected the Americans to be so indifferent to the Philippines that they would later barter it away during peace negotiations. From phase to phase the Japanese assumptions were inconsistent and contradictory. Assumptions changed to accommodate the goal of the moment.

This was a systemic problem within the Japanese high command. The Japanese never were good at formulating political goals and realistically determining the economic and military requirements to achieve them—witness their performance in China, Mongolia, and Korea.

The Japanese Decisive Battle strategy was questionable from the start. For example, what was to prevent the Americans from just turning around and refusing combat if they took too many losses during the Interceptive Operations? Of even greater concern, when testing their strategy in wargames, was that the Japanese found it impossible to locate the American fleet and execute their attrition attacks. In paper trials, Interceptive Operations and
Zengen Sakusen
could not be made to work. Perhaps as an expression of psychological avoidance, the basic Japanese plan was never given a trial in a full fleet exercise on the high seas.
⁶⁴

Japanese assumptions regarding the timing of the American counteroffensive consisted of unanswered questions and ill-founded premises. Why would the Americans move west after six months, with a force close to parity with the Japanese? Why would they not complete the salvage and modernization of ships damaged at Pearl Harbor and await the arrival of new construction reinforcements prior to moving west? Why would they continue an advance if heavy losses were sustained in the approach?

If Yamamoto’s attack on Pearl Harbor was a success it would work against the only strategy Japan had for victory. It would be a classic case of “win the battle, lose the war”—which was exactly what happened. The choices were never so dramatically illustrated than by a photograph of the battleship
Wisconsin
tied up alongside the salvaged hulk of the
Oklahoma
. The Japanese had the dilemma of either meeting
Oklahoma
at sea early in the war, or striking Pearl Harbor and sinking a few ships like
Oklahoma
, imposing a delay on the Pacific Fleet, and so later having to face the more modern and powerful
Wisconsin
and her consorts.