Remembering the war in New Guinea - Japanese strategy

Remembering the war in New Guinea
Japanese strategy (Longer text)
Module name: Strategy (Japanese perspective)
This page was contributed by Prof Arakawa Ken'ichi (National Institute of Defense Studies)

Pre-war Japanese official strategy is made clear in the "Plan to Facilitate the Completion of War Against the US, Britain, Holland and China" (the Plan). This Plan was drafted by the General Staff of the Army and ratified by the Army and Navy at an Imperial Headquarters liaison conference in November 1941. However, disharmony existed within the Navy Department between YAMAMOTO, the Commander of the Combined Fleet, who opposed the Plan, and Naval General Staff, who agreed with the Plan's general principles. YAMAMOTO advocated a "concept of continual decisive engagements", such as was seen in the attack at Pearl Harbour that opened the war. In other words, pre-war strategies to bring about the end of the war consisted of the Plan, and an unofficial strategy, namely the risky "short term battle concept" led by YAMAMOTO. Both plans ultimately sought to remove the American will to prosecute the war - only the means of achieving this differed.

The main thrust of the Plan was to quickly secure the southern resource belt so as to attain a position of self-sufficiency. At the same time, the US Navy would be lured into battle and destroyed. However, Japan did not have the capacity by itself to defeat the US in a direct confrontation. Therefore, Japan would form an alliance with Germany to force England to yield. With England defeated, the US would lose its motivation to continue prosecuting the war. On the other hand, YAMAMOTO felt that the qualitative difference in national strength between Japan and the US was patently obvious, and that any prolonged war between the two countries could only end in defeat for Japan. Consequently, the rapid destruction of the main force of the US fleet and the strategy of continually seeking decisive engagements would weaken the morale of both the US Navy and the people, forcing the government to seek peace at the negotiation table.

To what extent was the strategy of the Navy Department of Imperial Headquarters - a strategy close in conception to the Plan - put into effect in the pre-war period? The Navy to that point had planned for short-term decisive battles, but if the US had plans for a sustained conflict, there were fears that the US fleet would not advance into the Western Pacific. A sustained conflict was therefore anticipated. Consequently, in line with the strengthening of the Plan's sustained course of action, a policy to prosecute war was adopted. The Navy Department sought the destruction of the main force of the US Fleet using the core of the Combined Fleet, while at the same time securing the southern resource belt in a plan to sustain Japan's capacity to prosecute the war. However, even the destruction of the main force of the US Fleet would in no way lead to the end of conflict. Furthermore, the Navy Department had not sufficiently researched how best to maintain a sustained strategic position in the long-term. Specifically, they were unable to determine a possible line of advance to achieve a sustained position after formulating the main characteristics of their naval strategy. The only objectives of their strategic preparations were offensives against Australia, and in the Southern Pacific to cut the line of supply between Australia and the US.

The Imperial Navy Strategic Plan was formulated as the basis for the outbreak of war. Phase one strategies clearly identify the Bismarck Archipelago as a target for offensive operations. However, it is unclear how the strategies of phase two would secure this southern front. This phase simply contains orders for a formation, based on the 4th Fleet, to defend occupied territory in the islands of the South Pacific and the Bismarck Archipelago, and to destroy enemy advance bases by surprise offensives. Explanatory text for the strategic plan contained after the strategies of phase two states the following:
The enemy has established submarine bases in Northern Australia, New Guinea and other islands in the South Pacific in order to cause difficulties to our planned trade blockade. Great efforts must be made to destroy these advance bases through surprise attacks.

Furthermore, the Chief of Naval General Staff issued Naval Directive No. 1, which was based on this strategic plan, as a separate volume. Phase two strategies for the southern front outlined standard strategic policies for the Combined Fleet. Rabaul appears as an important base central to the defence of the occupied territories. When the draft of this strategic policy was unofficially made known to the Combined Fleet, it sought clarification of what strategic position should be adopted after the completion of phase one operations.

The Navy Department of Imperial Headquarters had not conducted sufficient research. Consequently, they indicated the following enemy advance bases that they wished to be destroyed if at all possible (only sites from the south-east front are quoted):
1. New Guinea, New Britain, Fiji, Samoa, etc.,

4. Key locations north of Australia

The Combined Fleet, upon receiving this directive, and with the consent of the Navy Department, interpreted the "attack" and "destroy" contained in the strategic orders as "occupy and destroy". In short, the Navy Department of Imperial Headquarters had not given sufficient detailed consideration concerning sustaining a long-term posture at the outbreak of war.

In fact, phase one operations proceeded much as expected after the outbreak of war. On the Papua and New Guinea front, Rabaul was invaded and occupied by Japanese forces in January 1942. From this point forward, however, Navy Department strategy diverged from the strategy of the Army as made clear in the Plan. The Navy Department of Imperial Headquarters (Naval General Staff) directed the Combined Fleet on 29 January 1942 to attack Lae and Salamaua, as well as Tulagi and Port Moresby (Navy Directive No. 47). The purpose of the operation was to attack key locations in the east of British New Guinea and the Solomons and to blockade the supply routes between the region and Australia. There were suggestions of an aggressive strategy concerning the south-east region over and above a simple defence of Rabaul. Namely, a position of sustained self-sufficiency was conceived for the occupied territories after the completion of phase one operations from the Plan. The Army at this stage were braced against attack from Russia and wished to redeploy troops to the north. The Navy Department began detailed research for phase two after the completion of the operations in the south, and considered attacking Australia. However, the Army did not want to be involved. (The Navy could not attack Australia by itself and sought the deployment of several Army infantry divisions. Their request, however, was flatly refused.) The Fiji-Samoa (FS) Operation was subsequently considered (operation to blockade Australia--US supply lines). Related to this operation was the determination to construct an airfield on Guadalcanal.

Navy and Army troops suffered heavy damage from Allied air attacks after the completion of their landing operations at Lae and Salamaua in the first half of March 1942. Despite this, various airfields and townships were occupied without significant loss of troops.

The "Outline of Future War Leadership" was formulated in March 1942. It planned an "active policy stance that recognises the opportunity to prepare a position of sustained victories to expand results achieved to date". This Outline, in accord with the Plan, did not make clear how the transition would be made from defence to self-sufficiency, or how to expand and continue aggressive operations.

Combined Fleet Headquarters was originally in a position to carry out the policies adopted by Imperial Headquarters. As mentioned previously, however, Commander YAMAMOTO's independent ideas were at odds with Imperial Headquarters (Naval General Staff) war planning. Even so, YAMAMOTO tried to implement his ideas without explanation to Naval General Staff or subordinate units. Consequently, the war strategy (war leadership policy) that was ultimately adopted by the Imperial Navy was the product of an exchange of ideas between Commander YAMAMOTO and Naval General Staff at Imperial Headquarters. Even the success in the opening operations in Hawaii were by any measure the result of the influence of YAMAMOTO's ideas on Naval strategy. Commander YAMAMOTO Isoroku had a war strategy to "press for short engagements by thoroughly assertive operations". The commander was aware of domestic conditions in Japan and the US and judged that the military capability of the US was greater. If war with the US did eventuate, the risk of being dragged into a sustained war was great because of the strategic policy of defensive ambush adopted by the Navy up to that point. Therefore, the plan he considered leant toward a short war that destroyed the US will to fight in one fell swoop through an independent, aggressive operation. This plan targeted the US, the most powerful of the Allied countries, with a surprise attack on Hawaii to destroy the main force of the US Fleet. It was thought that this would force the US to break from other Allied countries and to seek an end to the war, even while yielding to certain conditions. YAMAMOTO ordered his General Staff on 9 December, the day after the start of the war, to begin preparatory planning for further attacks on Hawaii and Ceylon. YAMAMOTO wished to proceed immediately with the offensive against Hawaii. However, he felt suppression of the US air strength at Hawaii, given the current Japanese air strength, would be difficult and that attacks were therefore unwise at that time. During the time needed to build the required air strength, a position of operational preparedness on the western front would be obtained through strategic operations against Ceylon. Efforts could then be concentrated on Hawaii.

Offensive operations against Ceylon, prepared and proposed by the Combined Fleet in the period prior to the realisation of the operation against Hawaii, were rejected by the Army and not adopted. For this reason, the Midway operation against US carriers was proposed somewhat as a stopgap measure. The Navy Department of Imperial Headquarters perceived a threat from Australia which had been established as a base for Allied counter-offensives, so wished to pursue operations in that region. The subsequent operational plan for the Combined Fleet in March confirmed the following:
Early May: offensive operations against Port Moresby (orders issued late January 1942)
Early June: Midway operations
Early July: FS operations (Fiji, Samoa)-- attack and destroy
October: proceed with preparations for offensive operations against Hawaii.

The offensive operations against Port Moresby in this plan were to be conducted by sea. The operations commenced as planned with the departure of the invasion force from Rabaul on 4 May. From 7-8 May, the first ever carrier-based air battle over sea took place. Losses on the Japanese side in the Battle of the Coral Sea amounted to one light carrier, with heavy damage to regular carriers, and the loss of numerous aircraft and crew. The Port Moresby invasion was stopped forcing the postponement of the operation until July. In June, the Navy suffered a defeat at the Battle of Midway resulting in a heavy loss for the Japanese. This defeat of the Japanese Navy was, among other things, a heavy setback for the short-term decisive engagement strategy of YAMAMOTO. Even so, the concept of a blockade of supply between the US and the Allied base of counter-attack in Australia was still foremost in the minds of the Naval General Staff. It had been stalled by the FS operation, but not as yet cancelled.

Related to this was the decision and subsequent preparations to establish an airfield on Guadalcanal. Oddly enough, even though the FS operation had been abandoned, construction of the airfield continued. In early August, after the completion of the airfield, US marines landed on Guadalcanal with the aim to retake the island. A war of attrition waged on and around the island between Japanese and US forces for the following six months. At the same time, Japanese forces launched an overland offensive aimed at Port Moresby (see the 1942 section for the Japanese Army occupation of Papua and New Guinea).

The Japanese Army continued to commit forces to the Guadalcanal campaign. Gradually, the army came to place more emphasis on the front in the South Pacific (Papua and New Guinea front) with respect to the overall war. To that point, they had adopted a stance of grudging co-operation with the Navy. However, they started to consider the great significance of the effect of the battles in the region on the overall war effort. Consequently, with the defeat of the 2nd Division in their attempt to retake Guadalcanal, the 18th Army, active on the Papau and New Guinea front, was reorganised on 9 November 1942. The 17th Army, to that point responsible for both the Solomons and New Guinea campaigns, was ordered to concentrate on the Solomons, while the 18th Army was reorganised and placed in command of the New Guinea front. The Emperor was presented with a strategic plan concerning the war on the South Pacific front by the Commanders of the Navy and Army on 18 November. According to this plan, "the purpose of the operations in the South Pacific remains the securing of key locations in the Solomons Islands and New Guinea area and thus maintaining our supremacy in the South Pacific region." Two days prior to the presentation of this plan, however, the transportation of the 38th Division as reinforcements to Guadalcanal had failed, and Allied forces had landed in the Buna area. These two circumstances, the destruction of the convoy carrying the bulk of the 38th Division, and enemy landings in Buna, forced a significant change of direction in Japanese military strategy in the South East Area. The construction of Allied air bases continued into December, as the difference in air strength between the Japanese and Allies increased. US forces on Guadalcanal continued to be well supplied, while the Japanese found it increasingly difficult to supply its forces. Further, US and Australian forces continued to press on Japanese garrisons at Basabua, Giruwa, and in the Buna area. With no possibility of reinforcement, the garrisons at Basabua and Buna fell. Japanese troops at the central position of Giruwa greeted 1943 in isolation.

Achieving the strategic objectives in the South Pacific in the plan presented by the Commanders of the Army and Navy on 19 November had become problematic. The Combined Fleet had secured eastern New Guinea in late November, and in the Solomons area, began to seek a change in strategic focus towards the central Solomons after abandoning Guadalcanal. Army commanders had come to place great emphasis on the region in the above-mentioned plan. Fierce debate erupted between the Army commanders and the Ministry of the Army who refused a request for an increase in sea transport required for the campaigns on the grounds of maintaining overall national strength. A temporary compromise was reached, but this resulted in the transfer of the heads of the Strategy Bureau and Strategy Office. By the end of December, the Army had abandoned even Guadalcanal and placed its strategic focus on New Guinea.

The adjustment of strategy in the South Pacific area was approved by the Emperor at a meeting on 31 December. The main points of this are as follows.

1. Withdraw from Guadalcanal, and maintain a line north of New Georgia and the Isabel Islands.
2. In the New Guinea area, withdraw units from Buna, maintain operations in key areas of eastern New Guinea by intensifying operations based on Lae, Salamaua, Madang and Wewak, and begin preparations for renewed operations against Port Moresby.

The Japanese in 1943 tried exhaustively to break the Allied advance northwards, all the while attempting to build military capacity with raw materials gained in the south without decreasing the general standard of living. In order to achieve their war objectives, they had to balance the contradiction between military operations and production.

The Allies had strengthened their land resistance at Salamaua, and had landed fresh units at Nassau Bay at the end of June. Further, they had recommenced offensives in the Solomons in late June with landings on Rendova Island. Ultimately, Japanese forces decided to abandon the central Solomons in August, and orders were issued to retreat from the Lae and Salamaua areas.

In September 1943, the Japanese forces determined an "absolute line of national defence", thus reforming the entire strategic leadership policy. Sections of this relating to the South East Area are as follows.
No. 1 strategic objective: to attack invading forces in key locations in the area, and by efforts of utmost persistence, pave the way for future operations.
According to No. 2, these key locations are the Bismarck Archipelago with a focus at Rabaul, key locations in the Bougainville area, both sides of the Dampier Strait, and key locations on the north coast of New Guinea.

It is possible to see the end of Japanese military strategy in the Papua New Guinea campaigns with the formation in September 1943 of the absolute line of national defence. Allied attacks after this time were focused on the Marshall and Gilbert Island areas. Australian and US forces continued to pressure Japanese forces north along the New Guinea coast. Landings were made in Aitape and Hollandia in April 1944, and on Biak Island in May. This so-called "island hopping" campaign bypassed Japanese strongholds rendering them impotent. From that time, the focus of the war moved on to the Marianas and the Philippines. Papua and New Guinea receded into the background.

Printed on 12/20/2018 01:41:59 AM