Defending the Imperial Fortress
In the closing days of December 1943, both sides were watching each other across the vast expanse of the Pacific Ocean. After two years the war had entered a new phase. The allies had endured the Japanese onslaught of the first months, checked it at Coral Sea and Midway and bled it to death in the Guadalcanal campaign. Both sides had suffered huge losses in men and materials, but both sides were determined to pursue their war aims to the end, notwithstanding the cost. The Japanese were still clinging to their basic assumption of limited war fought for limited objectives (in this case a negotiated settlement to save at least part, if not all of their initial conquests plus their holdings in China). While from a theoretical standpoint their war aim seemed easy and attainable, history has proven otherwise. In the end Imperial Japan was defeated, even if its position at the end of 1943 seemed much better than that of their European allies. In this article we will see how the Japanese armed forces planned to attain their goals in the second half of the war and why, from a strategic, doctrinal and planning point of view they were so utterly incapable of attaining them.
The Japanese Strategic Approach
Imperial Japan had slowly realized that its initial dream of a short victorious war was only that, a dream, and now it was locked on a strategic defensive position. Of course the imperial leadership still wasn’t ready to accept anything short of total victory. While the battles in the Solomon chain had claimed a huge number of ships, airplanes and soldiers the empire was still holding the majority of its conquests, especially the resources’ rich Dutch East Indies. In addition the bulk of the fleet, the traditional shield of the nation, was still untouched and available. They were sure that time and space was on their side. After all the latest American offensive action, the landing at Tarawa had shown how dangerous opposed landings were, and any drive toward Japan would have had to accomplish scores of these operations, clearing Japanese troops one island bastion at time, or worse, slugging with them in the heavily forested major island as was happening in New Guinea. In support of these strategic considerations there were also some geographical ones. The area was clogged of Japanese bases many of them capable to support major fleet operations, in addition Japan had the obvious military advantage of enjoying a central strategic position, enabling them to quickly reinforce every point of the frontline quicker than the allies could support each others’ drives.
So the Japanese strategy was one of attrition where the external defenses had to bleed the attackers until they were weak enough to allow the mass of the Combined Fleet to sortie and deliver a knock out blow to the Americans. After that they were sure that negotiations would have followed allowing a favorable settlement for Japan. It was the old Japanese naval doctrine rejected by Admiral Yamamoto with his daring and overambitious plans in the first year of the war. The basic defensive plan consisted of two areas, an outer perimeter, where the Americans would have been weakened by air and submarine forces in support of the island garrisons, and an inner one where, in addition to these elements, the main fleet would have sortied to wage the crucial decisive battle. While on paper it was a good plan, designed to exploit the strength of the Imperial forces while not exposing themselves to risks, it surrendered the initiative to the Americans and their ANZAC allies and depended on a slow methodical approach on their part. The decision to garrison atolls and islands everywhere was gambling and, as usual in Japanese military, a gross underestimation of the required logistical support for these bastions. In addition, the strategy put an unshakable faith in the power of land based air assets in the theater. For the strategy, to work the attackers had to be subjected to attrition by the aircraft placed on the outer islands and those aircraft had to be able to patrol the stretch of water between the various atolls to provide an unbroken “frontline”.
Basically it was a sound assumption and based on very real precedents in the war, Midway and Guadalcanal. In those battles the enemy airbases had proven to be a unsinkable carriers and had demonstrated to the Japanese admirals and generals the superior resilience of land based aircraft opposed to carrier based ones. If at Midway the atoll had been subjected to only one (albeit massive) air raid Guadalcanal had been pounded from the air and from the sea countless times, but it had always survived in a more or less operational shape. The Imperial Navy reasoned that the only way for the allies to neutralize the land based air forces was to seize every air base. In addition the reverse was also true; while the land based aircraft were still operational, no enemy naval force would have enjoyed freedom of movement. But some of the basic tenets of the strategy were too centered on the Japanese sides of the previous battles. Mainly the inability of carrier based airpower to deal with fixed airbases. Both at Midway and Guadalcanal the Japanese were unable – for their own force structure, technical limitations and doctrine – to mount a prolonged effort to neutralize these fixed bases so they were assuming that their opponents were working under the same restrictions; the following battles would have been instrumental to validate these underlining tenets.
The operational and tactical approach
Below the strategic approach, fully in accordance with the strategic priorities of Japan, the operational and tactical approach was entirely different. To implement a resolute strategic defensive concept, the Imperial Navy was counting on its time-honed predilection toward offensive action and decisive engagement.
If the strategic approach, agreed with the army, was based on a strategy of attrition, on the operational and tactical side, attack was the keyword. The land based air groups were expected to attack the allied naval forces, the land garrisons were expected to attack the enemy landing sites and reinforcements were supposed to execute counter-landing operations. And in the end the combined fleet was expected to sortie and defeat the enemy naval formations. While they were fighting a defensive war they hadn’t renounced to the primacy of the offensive described in their doctrine.
The Japanese Imperial Navy had entered the war with a basic doctrine centered on the decisive battle of annihilation This basic tenets were so ingrained in the Imperial Japanese Navy way of thinking that everything else had been sacrificed to them. Aircraft were designed to be well armed and maneuverable at the expense of protection and safety, the same for the warships. Japanese warships of every sized were capable of greater speed and punch than the majority of their counterparts, but were also more prone to internal fires, magazine explosion and other unpleasant surprises.
So it is not surprising that the navy was still nailed to these principles even with the current strategic situation.
This didn’t mean that the Japanese naval leadership was unaware of the disparity of forces in the theater, on the contrary, it was counting on the basic assumptions of its strategic plan to give to the combined fleet a tactical superiority sufficient to prevail in the field.
We have already seen how the admirals and generals in Tokyo were counting on the outer perimeter outposts to wear down and disperse part of the enemy forces then, while the American assault fleet was pushing deeper inside the empire the combination of land based airpower, submarines and garrisons would have acted in concert with the combined fleet to deliver a single knock out blow to the US Navy. Again, like during the centrifugal offensive, Midway and Guadalcanal, the plan depended on full coordination of different, often widely scattered, and independent elements to work.
A formation of Mitsubishi G4m bombers; the links between the various strongpoint of the perimeter were to be assured by massed formations of these aircrafts attacking American Task Forces
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