The disastrous defeat at Midway which followed the initial setback in the Coral Sea had great influence upon Japanese war planning. The Japanese Navy was compelled to revise its planning drastically: strategically from the offensive to the defensive. Its long-contemplated plan of invading New Caledonia, Fiji, and Samoa, and also of launching offensives against Hawaii through Midway, thus aiming to challenge and destroy the American Fleet while still maintaining its favorable strength ratio to the American Navy, eventually came to naught. While the Japanese Navy had just started strengthening its new strategical position after switching from an active concept of operations to a passive concept, it was completely surprised by the sudden landing of the American forces on the vulnerable Guadalcanal Island in the Solomons.
The fifth volume of Dr. Morison’s “History of United States Naval Operations”* covers the developments around the Solomons Islands from this period until the evacuation of the Japanese forces from Guadalcanal Island. Having served during this period as a staff officer in charge of operations of the local supreme naval command in that theater and having had numerous daily experiences with all the problems involved in the area, I am deeply impressed by the thoroughness of the book even in describing the accounts of the Japanese side, the description of which had to be based upon relatively few available materials and documents. Dr. Morison’s penetrating approach, his objectivity, and his criticisms are all laudable.
I would like to lake this opportunity to analyze some of the contributing causes for the failure of the Guadalcanal campaign, to explain the meaning of the developments which took place in that area, and at the same time make it clear how the operational concept of the Japanese Navy changed in the course of the campaign.
First of all, a word on the plans the Japanese Navy entertained before the war concerning this corner of the world. The traditional strategical policy to be employed by the Japanese Navy in case of war was, as often stated in the name of Yogekisa-Kusen, based on the idea of an all-out decisive battle with the American Fleet in which its transoceanic movement would be intercepted in the Western Pacific. When the war games were held for a few days in September, 1941, at the Staff College in Tokyo, members for the Fourth Fleet (whose principal mission was to defend the Inner South Seas Area) suggested the invasion of Rabaul and Kavieng to be followed by the invasion of Tulagi and Deboyne Island. In the study session appraising the results of the war game, however, the Headquarters Staff of the Combined Fleet made it clear that they were not in accord with that idea of the Fourth Fleet’s operational planning. The invasion of Rabaul, however, was considered necessary not only for facilitating the decisive sea battle in which the Japanese fleet would be launched from Truk area bases, but for defending Truk itself. It was concluded that the invasion should be launched at an appropriate time, but only after the early operations had progressed smoothly. Neither the Naval General Staff nor the Combined Fleet had at that time any intention of expanding their operations into the Solomons and Papua. Even the Japanese Navy, which was burdened with defending the eastern front of the Pacific almost independently, did not pay much attention to this corner of the world; the Japanese Army showed even less interest in it.
After the war started, the Fourth Fleet, as a result of a series of studies to cope with the situation as the theater command, considered it essential to advance as far south as Lae and Salamaua in eastern New Guinea and to Tulagi in the Solomons to defend the advance air base in Rabaul. On January 8, 1942, it sent, therefore, a recommendation telegram to that effect to the Naval General Staff and the Combined Fleet headquarters. Put it was not adopted at this time on the ground that even the advance of only a few elements of the naval air force to the Rabaul area would require the limited land-based air forces to deploy too widely.
As the southern invasion operations into Malaya and Dutch East Indies progressed so smoothly, much more favorably than previously thought, a sudden change was brought about in the operational policy of the Southeast Area, i.e., the Solomons and Papua. With the big success of the southern operations, the illusion that the United States and Great Britain were not worth being afraid of began to prevail among the Japanese Army and Navy from the top down. The caution heretofore exercised in operational policies suddenly disappeared. The Naval General Staff’s order issued on January 29 went so far as to instruct the invasions not only of Lae, Salamaua, and Tulagi, but even of Port Moresby. This order even surprised the Fourth Fleet, which had previously advocated offensives into that area.
What’s more—and this is noteworthy— not more than a handful of reinforcements were sent to carry out this new mission; the Fourth Fleet had to rely almost solely upon the forces it had on hand at the time. Hence the strength had to be spread out so widely that defense was ineffective, and construction of defense facilities and air bases was ignored. Not until late June was an advance survey group sent to Guadalcanal Island to build an air strip in the Tulagi area, although the invasion had been ordered in late January. It was not occupied until early May and at that time there were no construction units available to the Fourth Fleet. It was only after the Midway defeat that the 11th and 13th Construction Units, originally slated for Midway Island, were transferred to that fleet, but it was not until early July that construction work commenced on Lunga air strip. Moreover, there were no operational air strips in the intermediate 600 miles between Rabaul and Guadalcanal Island, a fact which later proved to be bitterly expensive to the Japanese.
The 8th Fleet headquarters, which was advanced to Rabaul on July 30, just ten days before the American landing on Guadalcanal Island, worried about the situation and immediately set about to remedy it. On investigating this problem at the time, I was greatly surprised to learn: (1) that thus far no suitable places had been found for air strips in the intermediate area, and (2) that since the Japanese naval air force was reduced in strength, it intended to send only a small, temporary force to Guadalcanal. Not only that, but this force was to be sent after the completion of the air strip and then only when it was deemed necessary.
Such being the circumstances surrounding the initial problem on Guadalcanal, the Japanese as a matter of course failed to repulse the first American offensive against the island. The Japanese consequently were compelled to resort to piecemeal tactics which resulted in a delaying war of attrition, in which the Japanese Navy lost most of its highly skilled land-based air force—an irreplaceable fighting outfit. Thus stripped of its main fighting strength with which to stem the tide of American offensives, Japan was left with natural barriers wide open. This was one of the major causes for the defeat of Japan in the Solomons.
The next problem has to do with the fact that countermeasures taken by the Japanese against the American landing on Guadalcanal Island on August 7 lacked thoroughness owing to an underestimation of American fighting strength. The Japanese, therefore, lost an excellent chance to turn the tide of battle. That Vice Admiral Mikawa lacked the determination to deliver a fatal blow against the enemy in the Savo Island sea battle, that lie also planned to retake the island with a mere handful force of only 450 men under his command and that the Ichiki Detachment of the Army met the doom of being annihilated in its attempt against the island, all these suffice to show that the-Japanese were then suffering from the so-called “victory disease.”
Admiral Yamamoto, C-in-C of the Combined Fleet, at that time wrote to Vice Admiral Mikawa, 8th Fleet Commander as follows: “The situation on Guadalcanal Island is very serious; much more serious than that the Japanese confronted in the Russo-Japanese War when they had to occupy Port Arthur before the approach of the Baltic Fleet to Far Eastern waters.” He also revealed that unless a major operation was rapidly launched with at least three more divisions, grave consequence would follow. Even this opinion from Admiral Yamamoto was ineffective in the face of the prevailing optimistic view entertained throughout the Army and Navy. That the Japanese needed to deliberate for an entire month before reaching a decision on the policy of shifting emphasis to the Solomons was due entirely to the strong opposition offered by members of the Japanese Army who entertained over-optimistic views.
Regardless of whether they liked it or not, the successive battles fought around Guadalcanal turned out to be exercises in serious attrition for the Japanese forces. The Japanese Navy lost most of its once-powerful carrier borne air forces in the Midway sea battle; the further loss of its skilled land-based air forces, upon which the Japanese Navy placed such great hope, was indeed a fatal blow since there was little chance of replenishing these forces.
While the Japanese naval air forces fought desperately in this area, the Japanese army air forces were idly stationed on the continent and in the southern districts, offering the Navy no co-operation and no help. So slow were they to turn their attention to this district that it was not until the middle of
December—by which time the pattern of defeat on Guadalcanal was so obvious that evacuation problems were already under discussion—that a handful of the army air force arrived in the theater. The principal reason for this was the Japanese Army’s stand that they would not shake loose from their preparations for eventual war with Soviet Russia, so the Navy had to bear the responsibility for the eastern front in the Pacific. This was quite enough to show that the Japanese Army and Navy lacked a coordinated and long-term policy of how to direct the war as a united effort.
The outstanding feature in the Guadalcanal campaign in the field of tactics was the employment of radar by the United States, which completely reversed the Japanese Navy’s traditional superiority in night engagements. It was after the Esperance sea battle on October 11 that the Japanese Navy confirmed the use of effective fire control radar by the United States. The fact that the Japanese lost confidence in night engagements, which had hitherto been considered their most effective means of compensating for inferior air power, was a bad influence upon the morale of the men as well as upon the subsequent operations of the Japanese Navy. With the middle of September as its turning point, the once high morale of the Japanese destroyer crews participating in the so-called “Tokyo Express” for transports to Guadalcanal Island soon suffered a letdown. This lack of confidence in night engagements resulted in disclosing physical and mental defects of the Japanese naval forces which participated in the Guadalcanal sea battle fought from 12th to 14th November. In consequence, the Japanese force sustained great losses which had a decisive significance. As a result, there remained little hope of remedying the already dwindling situation of provisions and ammunitions on the island, much less of turning the tide of the campaign there. Mounting losses due to the adverse condition of the night engagement, especially the rapid increase of destroyer losses, made it almost impossible to meet even the army’s minimum demand of supply transport.