Japanese military strategies in 1942
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Immediately after the fall of Singapore in 1942 certain Army circles argued that Japan should exploit her advantage and seek peace with Great Britain. The heart of this reasoning was the fact that Japan could not knock out both the United States and England, judging from such factors as national strength and geographical location.
The Soviet Army had recovered from its initial setbacks in the war with Japan's ally Germany, and had regained its feet. Under the circumstances, Japan should plan to conclude a so-called compromise peace, seizing the opportunity after attainment of her war objectives. This sentiment was held by very few people, however, and most of the military paid scant attention to it.
Planning for and prosecution of war then followed.
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[edit] March outline of war direction
On March 7, 1942, an IGHQ (Imperial General Headquarters) -Government Liaison Conference decided upon a general outline of policy for subsequent direction of the war. The basic aims of the program follow:
A. In order to bring about Great Britain's surrender and America's loss of will, Japan should continue to enlarge the scope of the war gains already achieved, and endeavor to establish an invincible structure for protracted warfare, from the standpoint of both politics and combat. B. Japan should seek to effect a self-sufficient basis, strengthening the war potential by exploiting, developing, and utilizing vital national resources.
[edit] Army resistance
Within the Army, there were certain objections to the preceding principles. Insistence was strong that Japan should not, during the second-phase operations, enlarge still further the areas already secured. Instead powerful defenses ought to be erected throughout the occupied territories.
The war potential ought to be built up as soon as possible, especially insofar as aircraft were concerned. With reinforced materiel, the third phase of the war should be entered, wherein the counterattacks of the American and British armies would be defeated. This view was especially pronounced within the Operations Bureau of the Army General Staff.
[edit] Expected counterattacks
Between February and March 1942, Imperial Japanese headquarters was anxious about the next steps which were to follow the close of the first-phase operations.
In planning second-phase operations, the most important considerations were definite forecasts of the timing and the scale of American and British counterattacks. The Army Operations Bureau estimated that counter-offensives could be expected starting in 1943. Two basic elements went into the formulation of this judgment. First, the Navy believed that it would take at least a year for the U.S. Pacific Fleet to recover from the grievous damage sustained at Pearl Harbor; the Army shared this view. Secondly the General Staff felt that the U.S. Army would undertake its projected Far Eastern operations with comparatively small forces, inasmuch as they would be concentrating the preponderance of their strength on the European front.
As for the scale of counterattack, the operations people could make no definitive estimate, because they had no basis for forecasting. Some of the staff officers thought that the counteroffensive might center around a force of several Marine Corps divisions.
[edit] Misjudgment of American response
The estimates proved overly optimistic. The American counter-assault began in the latter half of 1942. One reason why this counterattack materialized sooner than expected was the fact that the Japanese Navy had not damaged shipbuilding and repair facilities, or oil stores, during the raid on Pearl Harbor.
Two further factors underlay the Army's underestimation of the prospects of an American counterattack. First, they agreed with the Navy's view that islands are unsinkable aircraft carriers, extremely formidable in defensive strength. Secondly, the Naval High Command resented Army proposals concerning operations in the Pacific areas which lay within the defensive purview of the Navy.
[edit] Objectives considered
[edit] Capture of Hawaii
An operation which the Navy very strongly advocated was the capture of the Hawaiian Islands. This would have involved landings subsequent to the conclusion of the first stage of the war. The operations bureaus of both the Army and the Navy investigated the matter on a number of occasions. When it became apparent that the Hawaii operation was beyond the capability of the Army to carry out alone, the General Staff vigorously resisted the project, which was eventually discarded.
After the projected Hawaii landings, the next serious interservice problem arose concerning the concept of Outer Perimeter operations. The primary goal would be the strengthening of Japan's defensive posture by the capture or control of strategic sectors outside the zones occupied during the first-phase operations. It was, moreover, intended to utilize the key strategic points as springboards for offensive action, if possible.
[edit] Other objectives
Objectives which the Army High Command considered during this phase included the Aleutians, Fiji, Samoa, New Caledonia, eastern New Guinea, Cocos Island, eastern India, Colombo in Ceylon. In the face of the Army plan, the Naval High Command insisted upon occupying Australia, a desire which stemmed from their concept of pursuit operations and followed their easy conquest of the Bismarcks Archipelago in January.
[edit] Army-Navy disagreement
The Army High Command objected to the Navy scheme for two reasons:
- To take possession of Australia was so clearly beyond the limits of Army offensive strength that it would be difficult to maintain or to supply the combat forces required
- The Army possessed no extra forces to commit; yet ten divisions would be necessary to carry out the Australia operation.
The clash between Army and Navy operational planning was largely due to the differences in views concerning maneuver. Unlike the Army, the Navy does not have such great requirements for lines of communication. Reserve stocks are not imperative for naval forces, since warships can set off for their objectives loaded with enough provisions and ammunition to last them several weeks. If things turn out badly, they can easily head back for their bases.
Ground movement is not so easy, however. The greater the size of the Army forces, the greater the logistical requirements; nor can ground troops shift their axis of operations once underway. The Army accordingly finds it necessary, when large-scale operations are undertaken, to make thorough preparatory studies of logistical feasibility. Very great attention must also be devoted to the proposed axis of operations. Under the circumstances, the Army and the Navy were barely able to agree upon the following major objectives of the Outer Perimeter operations: New Caledonia, Fiji, Samoa, Port Moresby, and the Aleutians.
[edit] May assessment of Far East operations
Toward the end of May 1942, the High Command formulated estimates of the current situation in the Far East. In all of the areas occupied during the Southern Army operations, the recovery of public order and the proliferation of military government administration were going well. IGHQ's pressing intentions included the establishment of a defensive and self-sufficient footing in the southern regions as soon as possible, and the strengthening of the nation's power and war potential through improvements in discipline, redeployment of military forces, and acquisition of strategic natural resources. In order to achieve the goals of the war, however, Chiang Kai-shek and the British would eventually have to be brought to their knees, while the United States must be compelled to abandon the will to fight. Dealings with the Soviet Union were also important. In laying out future operational plans, Japan must accordingly co-ordinate timing, priorities, and methods of implementation with her national strength and surrounding circumstances.
[edit] Misjudgment of US/British forces
In devising its estimates of the situation, the Army underestimated the counteroffensive of the American and British armies. The previously cited judgments, in fact, were based not so much upon coming counterattacks by the United States and England, as upon an inclination to take it easy after winding up the first-phase operations and to evacuate almost all of the forces from the southern regions.
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The question then arose as to just how many troops should be left in the south. The Ministry of War felt that some 21 battalions would suffice, but IGHQ opposed this as being too few. Thus the High Command authorities were relaxing their outlook and evincing great confidence; they were, in short, crowing too much. It was far too late when Premier Tojo, in early 1944 (at a time when the American offensive was becoming massive) expressed his opinion of deep regret that the Army had done nothing back in 1942. The mental letdown within the High Command after the termination of the first-phase operations exerted a baleful effect upon the entire war situation thereafter.
This mental relaxation could be observed not only in Tokyo but in the Southern Army as well-which was perhaps only natural. The Southern Army, for example, united its headquarters Intelligence Section with the Operations Section after the close of the first phase of the war, alleging that the intelligence staff had lost its raison d'etre at that stage. This action of the Southern Army, ignoring the intelligence function, was taken without the approval of IGHQ and typified contempt for the combat strength of the Allies. There was consequently an inability to forecast the large-scale counteroffensives launched by the Americans and the British in the near future. Indeed, the Southern Army's Intelligence Section was not re-activated until February 6, 1944.
[edit] Redeployment in China
As a result of consultations with the War Ministry concerning the military establishment after the termination of the first-phase operations, the Army High Command decided upon certain principles of redeployment.
In the southern districts, only the forces required to execute the Outer Perimeter operations would be left; other strength would be transferred elsewhere. Most of the units were to be returned to the homeland, while a portion would be diverted to Manchuria and China.
In Manchuria, preparations were to be made for co-operation, at any time, with the progress of the German Army in Russian Front. In China, pressure would be intensified against Chungking, taking advantage of the strength released from the successful southern operations.
The essentials of the project were as follows:
- 1. Southern Regions: Rearrange the system of military administration in effect throughout the occupied areas. Return the 2nd Imperial Guard, 4th, and 5th Divisions to the homeland. Dispatch the 33rd Division to China, the 16th to Manchuria. Place the Fourteenth Army under the direct control of IGHQ.
- 2. China Theater: Transfer the 33rd Division from the southern regions. (This plan could not be effected in practice.) Activate one armored division and six infantry divisions (59th, 60th, and 68th through 71st).
- 3. Manchuria: Activate two Area Army headquarters, one Army headquarters, one Mechanized Army headquarters, and two armored divisions: 1st and 2nd, with headquarters at Mutanchiang and Poli, respectively. Return older troops to the homeland; rejuvenate the remaining units.
[edit] July mobilizations
On July 4, 1942, IGHQ ordered the following units activated:
- First Area Army (commanded by Lieutenant General Tomoyuki Yamashita, with headquarters at Mutanchiang).
- Second Area Army (commanded by Lieutenant General Korechika Anami,with headquarters at Tsitsihar).
- Second Army (commanded by Lieutenant General Yoshio Kozuki, with headquarters at Yenchi).
- Mechanized Army (commanded by Lieutenant General Shin Yoshida, with headquarters at Ssupingchieh).
- Homeland Area: Activate the 52nd Division. (This could not be accomplished.)
- Air Force: Set up Third Air Army Headquarters in the southern region, with about five air groups. This headquarters is to control air defense operations in key areas on Sumatra and Java, as well as handle offensive actions overseas against India and China.
The order of battle of the Third Air Army was issued on July 10, 1942. Lieutenant General Hideyoshi Obata was the commander, with headquarters at Singapore.
On June 29, 1942, IGHQ issued a set of orders to General Hisaichi Terauchi, commanding the Southern Army. The essentials follow:
- A. In order to bring the war to a successful close, IGHQ requires the maintenance of stability in vital portions of the southern regions, and the establishment of self-sufficient, impregnable foundations. Operations must, moreover, be prepared in conformity with all possible eventualities.
- B. In conjunction with the Navy, the Army Commander should endeavor to stabilize important regions in the south, and to prepare Outer Perimeter operations based upon the below-cited precepts:
The Army should seek to complete the defense of these areas, and to extend military administration throughout.
- 2. Thailand, Indo-China:
The Army will co-operate with the authorities in their defense.
IGHQ also directed the Southern Army to undertake a number of measures:
- A. Set up air bases in French Indo-China, Thailand, Burma, Malaya,
Sumatra, Java, and the Philippines. Singapore will be the hub.
- B. Expand facilities for supply and for the repair of aircraft.
C. Intensify local self-sufficiency, in order to decrease supply requirements upon the homeland.
[edit] Planned operations in Outer Perimeter
The major Outer Perimeter operations which the High Commands of the Army and the Navy had agreed to execute included, as we have seen: the seizure of strategic points on New Caledonia, Fiji, and Samoa; and the capture of Port Moresby and the Aleutian Islands.
[edit] Midway
As a direct result of the Doolittle bombing raid on Tokyo in April 1942, the Naval High Command heeded the strong recommendations of the Commander-in-Chief of the Combined Fleet and decided to initiate operations against Midway. The Navy proposed to the Army High Command that the Midway Operation be carried out, at all costs, before the commencement of action against Fiji and Samoa. The Army reached a compromise with the Navy concerning its demand; it was decided that both the Midway Operation and the Aleutians Operation would be launched simultaneously, prior to the attacks upon Fiji and Samoa.
[edit] Port Moresby
The Port Moresby Operation marked the outset of the Outer Perimeter project, but operational thinking had often been revamped in the interim. Originally, as we have seen, it had been intended to have the South Seas Detachment land near Port Moresby directly from the sea, before the American and Australian forces had been reinforced. The air facilities were to have been seized and consolidated as soon as possible.
On May 4, 1942, troopships bearing the South Seas Detachment set sail southward from Rabaul for Port Moresby. Three days later, however, a naval engagement appeared to be brewing in the Coral Sea; whereupon the transports immediately veered back to the north, in order to avoid combat. The Battle of the Coral Sea caused no small loss to the Fourth Fleet. Plans to land the South Seas Detachment directly at Port Moresby from the sea had to be abandoned.
IGHQ, on May 18, 1942, issued an order of battle for the Seventeenth Army, to be commanded by Lieutenant General Haruyoshi Hyakutake. An Army in name only, it was made up of several infantry regimental groups: 35th Infantry Brigade less 114th Regiment; South Seas Detachment; Aoba Detachment (built around 4th Infantry Regiment); 41st Infantry Regiment; etc. The mission of the Seventeenth Army was the capture of strategic points on New Caledonia, Fiji, and Samoa, as well as the occupation of Port Moresby-all in co-operation with the Navy.
The objective of these operations was to take possession of strategic island points, in order to intensify a cutoff in the contact between the United States and Australia, while squelching the Americans' and Australians' plans of counterattack from the same areas. Action was slated to begin about the beginning of July 1942, using the following forces:
- Bulk of the Seventeenth Army (built around nine infantry battalions)
- Second fleet Air arm built around First Air Fleet
[edit] Results of the Battle of Midway
Based upon the operational plans, Army troops were steadily making operations for combat when, on July 11, IGHQ ordered the suspension of the projected actions against New Caledonia, Fiji, and Samoa, because the Combined Fleet had failed at Midway. Reasons for the suspension of operations may be further summarized:
- The Combined Fleet had been badly hurt in the Midway battle.
- From the experience at Midway, it had been learned how difficult it was to attack an island.
- The opinion was gaining ground that it would be more advantageous to step up operations in the western Indian Ocean, in conjunction with the actions of the German Army, and to drive upon the Suez Canal.
[edit] Seventeenth Army and Port Moresby operations
With the release of the Seventeenth Army from the mission of attacking New Caledonia, Fiji, and Samoa, IGHQ assigned a new double objective: the capture and security of Port Moresby, in co-operation with the Navy; and the opportune seizure of strategic points in eastern New Guinea. Army components which were to participate in the new operations against Port Moresby included the bulk of the Seventeenth Army (about six infantry battalions, primarily); naval forces comprising the Eighth Fleet; and units built around the 25th Air Regiment. According to the plan, the main Army strength was expected to capture Port Moresby and the nearby airdromes, from the direction of Kokoda and Buna, as soon as possible. The Navy would undertake to defeat the American and Australian air forces, master the U.S.-Australian Fleet, and furnish direct support for the land operations.
An Army unit had been reconnoitering the road across the Owen Stanley Mountains, which extend north of Port Moresby. Without awaiting the reconnaissance reports, the Seventeenth Army Commander hastily landed the South Seas Detachment near Buna in mid-July 1942, and then rushed them toward Port Moresby.
The South Seas Detachment tried to get across the Owen Stanley Range, struggling with the tortuous topography, the jungles, disease, hunger. The march was literally agonizing. After defeating two battalions of Australians, the detachment pushed to within hailing distance of Port Moresby but, finally, it proved absolutely impossible to maintain supply lines forward.
On August 28, the Army therefore had to order the detachment to hold up its advance. A month later, on September 23, orders were given to withdraw to the neighborhood of Buna. The detachment started to pull back from its advanced positions in the Owen Stanleys on September 25, harried by the pursuing Australian Army all along the way. Not until the end of October did the Japanese manage to struggle back to Kokoda; they eventually reached Buna toward the end of November.
[edit] Seventeenth Army and Guadalcanal operations
Fighting had meanwhile erupted on Guadalcanal Island. On August 13 the Seventeenth Army (with the Ichiki Detachment in support) was ordered to continue the eastern New Guinea Operation, while simultaneously recapturing Guadalcanal in concert with the Navy. The Seventeenth Army, however, was far too preoccupied with operations on Guadalcanal to pay much attention to eastern New Guinea.
[edit] Formation of Eighteenth Army
Under the circumstances, IGHQ (on November 16) ordered the formation of a new army - the Eighteenth - to concentrate upon the East New Guinea Operation. Lieutenant General Hatazo Adachi commanded the new army, which was built around the South Seas and the Yamagata detachments. The mission of the Eighteenth Army was to secure strategic operational points near Lae, Salamaua, and Buna; and to prepare for future campaigns by intensifying air operations, to include additional combat and liaison air fields on New Britain and New Guinea. Thus the axis of operations on eastern New Guinea veered toward Buna, Lae, and Salamaua.
The objective of the Midway Operation was the seizure of the island, including Kure, an isle lying to the northwest. The U.S. Army was thereby to be prevented from launching operations against Japan Proper from the direction of Hawaii. On the other hand, the American Fleet was to be destroyed if it appeared while the Japanese were attacking Midway.
In accordance with Naval requests, the Army decided to use the Ichiki Detachment for the projected operation. Colonel Kiyonao Ichiki, who commanded a force centering about one infantry regiment, was ordered (early in May) to capture Midway in conjunction with Navy units. The plans called for landings to be made on June 7 by an assault grouping made up of the Ichiki Detachment and the 2d Combined Special Naval Landing Force, with the support of the main body of the Combined Fleet.
[edit] Battle of Midway
Near Midway Island, fresh American Naval forces lay in wait. The Japanese Navy's carrier force suffered terrible losses on the high seas around Midway, and the outcome of the battle was decided before the Japanese landing detachments could actually invade the island. The Ichiki Detachment therefore fell back at once toward Guam, where it was removed from the command of the Combined Fleet and instead came under the direct control of IGHQ. As we have seen, the Detachment was subsequently diverted to the Guadalcanal Operation.
[edit] Implications of loss at Midway
The failure of the Midway Operation was caused by slight negligence, but the effects were so tremendous that Japanese Army operations in the Pacific were shaken to their very roots. Because of the failure, the Japanese Navy also lost its mastery forever, since a quick recovery from the smashing blow to the carrier fleet was impossible. It was difficult for Japan either to build large aircraft carriers or to train skilled airmen overnight.
A tremendous diminution in aircraft carrier strength entails loss of air supremacy; and where air power is absent, it is difficult to exercise command of the sea. In this manner Japanese forces in the South Pacific area lost all chance of gaining control of either air or sea. Inevitably the tide of war grew gradually more unfavorable for the Japanese Army in those regions, beginning in the latter half of 1942. The after-effects of the defeat at Midway were grievous for Japan.
[edit] Aleutian Islands
[edit] Assessment of Soviet intentions
Before initiating operations in the Aleutians, IGHQ studied the possible effects upon the Soviet Union, and reached the following conclusions:
- A. No hostilities would break out between Japan and Russia as long as Japanese forces did not violate Soviet territory.
- B. A problem might arise if and when U.S. military aircraft made forced landings on Russian soil.
- C. Japan must keep an eagle eye open if American military bases should be established in Soviet territory. If this event materialized, Japan should clearly demonstrate to the Russians her interpretation of the situation, well in advance; i.e., that such action would constitute a breach of the Neutrality Pact in existence between the U.S.S.R. and Japan.
[edit] Strategic objectives
After conducting intensive deliberations as to where to draw a line during the projected Aleutian Operations, IGHQ decided to settle for the mere occupation of territory rather than wage a campaign of destruction. The objective would accordingly be the seizure of American offensive bases aimed at Japan Proper.
[edit] Planning
Meteorological conditions would have to be taken into consideration in launching the operations, for it was reported that large-scale ground action was extremely difficult around Attu and Kiska islands because of storms, coldness, and dense fog. Such operations appeared feasible during five months only: March, April, May; September and October.
The Army therefore decided to dispatch the North Seas Detachment to the Aleutians. Major Matsutoshi Hozumi, in command of this Detachment, possessed a force built around one infantry battalion. His mission was to occupy the islands of Attu, Kiska, and Adak, in conjunction with naval units.
[edit] June landings
On June 7, 1942, the North Seas Detachment landed on Kiska, and the next day upon Attu, without meeting resistance. No landings were made, in Adak and the mission of occupying that island was canceled on June 25.
IGHQ (on October 24) reinforced the North Seas Detachment and also changed its name to the North Seas Garrison Unit. Commanded by Major General Juichiro Mineki, the force was primarily composed of three infantry battalions and was under the operational control of the Commander-in-Chief of the Fifth Fleet.
The American Army constructed air bases at both Adak (about the end of August 1942) and at Amchitka, near Kiska (around February 1943). On March 26, 1943, a naval battle occurred near the Komandorski Islands, within Soviet territorial waters, but neither side suffered serious losses.
[edit] American counterattack
About a month and a half later (on May 12) about one division of American troops began landings on Attu, under cover of powerful aerial and naval forces.
Despite careful study of the possibilities of reinforcement and recapture of Attu, IGHQ could take no positive action because of the lack of both naval and air power. Isolated and helpless, the Attu Garrison Unit (over 2,000 men) fought bravely with ever dwindling forces. The difference in strength (especially in fire power) was far too great, however, and severe losses were sustained under incessant bombardment by warships. Finally, on the night of May 29, the unit commander, Colonel Yasuyo Yamazaki, ordered a last attack by his remaining troops.
[edit] Decision to withdraw
Previously, on May 20, an IGHQ Conference had been held at the Imperial Palace, attended by the following individuals: the Chiefs of General Staff of the Navy and the Army; the Deputy Chiefs; the heads of the Operations Bureaus; the Chiefs of the Operations Sections; the Ministers of War and of Navy; and the Senior Aide-de-Camp to the Emperor. In the Imperial Presence, the problem of changing the Northern operational plan was closely examined.
The Conference frankly acknowledged that island operations without command of the air and the sea face no alternative but self-destruction. It was decided to pull out the Kiska force; that very day, the Commander of the Northern Army(Kiichiro Higuchi) was ordered to attempt to extricate the western Aleutian units.
Plans were drafted to withdraw the troops from Kiska on warships. The evacuation proceeded smoothly, without interference from the Americans. All personnel reached Etorofu Island in the Kurils on July 31 and August 1. IGHQ now commenced to strengthen the defenses of the Kuril Islands in earnest.
[edit] Guadalcanal
On Guadalcanal, several hundred Japanese marines and about 2,000 construction men were building an air field. Not until August 7, 1942, however - when American troops landed on the island - did the Army High Command first become aware of the fact that an air base was being constructed and that naval forces were involved. The Americans simultaneously came ashore at Tulagi.
[edit] US seizure of airfield
Immediately after effecting landings on Guadalcanal, one division of U.S. Marines seized the airstrip which was under construction. If the airdrome had only been completed and the Japanese Air Force had commenced operations, the New Hebrides and New Caledonia, as well as Australia and New Zealand themselves, would have been exposed to the threat The American Marines therefore sought to capture the air base before the Japanese could put it into operation.
[edit] Seventeenth Army ordered to retake Guadalcanal
Upon learning of the American landings on Guadalcanal, IGHQ - on August 10 - ordered the Ichiki Detachment and the Aoba Detachment (then undergoing training with the Fourteenth Army) to join the Seventeenth Army under General Hyakutake. Three days later, orders were issued to recapture both Guadalcanal and Tulagi, in addition to carrying out the Port Moresby Operation.
It is over 1,000 kilometers from Port Moresby to Guadalcanal. IGHQ nevertheless assigned two simultaneous area missions to the Seventeenth Army, because there were no other units to employ in the area immediately. IGHQ's outlook regarding the recapture of Guadalcanal was far too optimistic.
[edit] Sea battles
Many sea battles broke out near Guadalcanal. In the first battle of the Solomons (on the night of August 8), the Japanese Navy achieved good results because of its sudden attack. The second battle (on August 24) was fought between aircraft carriers, and only slight losses were suffered by either side. In the engagement off Savo, during the night of October 11, the U.S. Navy took the initiative and the Japanese fleet was badly damaged. From October 25 through the night of the 26th, both sides incurred considerable losses during sea battles in the South Pacific. The third battle of the Solomons (which lasted from November 12 until the night of the 14th) resulted in comparatively great total success for the Japanese Navy. In addition, Japanese warships often threw American positions near the landing site into confusion, or bombarded the U.S. defenses from the sea.
Because the Japanese Navy was short of strength required to secure mastery of the air or the sea, it was necessary to fight most of the naval battles at night. Since neither the sea nor the air could be controlled, moreover, the transportation of supplies to Guadalcanal was gradually severed entirely, and some of the garrison eventually starved to death.
[edit] August assault
The bulk of the Ichiki Detachment, transported in haste by destroyers from Guam, landed on Guadalcanal during the night of August 18. Since the destroyers could haul only small quantities of weapons and ammunition besides troops, the Detachment's fire power was accordingly very weak. In the course of attacks against the air field from the night of August 20 to the morning of the 21st, the Japanese suffered terrific losses from the dominant artillery and armor of the Americans, because of insufficient assault preparations. On the 21st, moreover, American light aircraft were already using the air strip.
[edit] Attempt to reinforce
After the dispatch of most of the Ichiki Detachment to Guadalcanal, the remainder of that force, plus part of the Kawaguchi Detachment, were shipped in. En route to the island, however, they were attacked by American aircraft (on August 28) and were never heard from again.
On August 29, IGHQ transferred the 2nd Division (commanded by Lieutenant General Masao Maruyama, then on Java) to the order of battle of the Seventeenth Army. At the same time the army was ordered to devote priority to the mission of recapturing the Solomons. (Until then, the Seventeenth Army had had the primary mission of conducting the Port Moresby Operation, and the secondary task of retaking the Solomon Islands; the emphasis was now reversed.)
[edit] September assault
By September 4 the bulk of the Kawaguchi Force (including the Aoba Detachment's three infantry battalions from the 2nd Division) had landed on Guadalcanal. On the night of the 13th a second assault was launched against the air strip, involving the main force of the Kawaguchi Detachment (about five infantry battalions) and the remainder of the Ichiki Detachment (about 100 men). The Japanese bravely attacked, and the decision remained in doubt for several hours while chaotic confusion gripped the fighting lines. Part of the Detachment once penetrated a corner of the air field, but could not hold on to its gains because American reserves were thrown into the battle and a furious enemy bombardment was unleashed. As a consequence, the second Japanese attack also ended failure.
[edit] Doctrinal changes as result of losses at Guadalcanal
The Army High Command, after studying the methods of attack in practice till then, decided to change the operational principles, on September 18. The old rough-and-ready ways of attack meant that troops would be rushed into an assault with insufficient strength. This concept was changed, so that frontal assaults would be staged only after all reinforcements had arrived and careful offensive preparations had been completed. The combined power of both Army and Navy elements would thereby be exploited fully.
