1. This chapter was originally prepared in Japanese by Maj. Toshiro Magari, Imperial Japanese Army. Duty assignments of this officer were as follows: Faculty, Japanese Military Academy, 7 Jul 41-10 Dec 42; Army Staff College, 10 DEC 42-31 Jul 44; Staff Officer (Operations), Thirteenth Army, 31 Jul 44-15 Aug 45. All source materials cited in this chapter are located in G-2 Historical Section Files, GHQ FEC.
3. Initial steps to combat the growing submarine menace to Japanese shipping were taken in the latter part of 1943. On 1 November, Fourteenth Army was ordered by Imperial General Headquarters to cooperate with the Navy in providing security for convoys in the waters adjacent to the Philippines by the assignment of Army aircraft to escort and patrol duty. On 15 November the Navy established the General Escort Command and launched serious study of measures to strengthen the convoy system and improve submarine detection devices. (1) U.S. Strategic Bombing Survey (Pacific), Naval Analysis Division, Interrogations of Japanese Officials, 1946. Vol. II, pp. 440-1. (Interrogation of Capt. Atsushi Oi, Staff Officer (Operations), General Escort Command; and Comdr. Kiyoshi Sogawa, Imperial General Headquarters, Navy Section.) (2) Hito Sakusen Kiroku Dai Niki (Philippine Operations Record, Phase Two) 1st Demobilization Bureau, Oct 46, p. 27. American Editor's Note: The success of American submarine "wolf-packs" in these waters was made possible largely by radio intercepts and prompt intelligence transmittal by coast-watcher teleradio stations established in the islands in increasing numbers despite severe Japanese counter-intelligence measures.
4. Hito Sakusen Kiroku Dai, Sanki Dai Ikkan Hito ni okeru Dai Juyon Homengun no Sakusen Jumbi (Philippine Operations Record, Phase Three, Vol. I: Operational Preparations of the Fourteenth Area Army in the Philippines) 1st Demobilization Bureau, Oct 46, p. 30.
5. (1) Hito Homen Kaigun Sakusen Sono Ni (Philippine Area Naval Operations, Part II) 2d Demobilization Bureau, Oct 47, P- 37. (2) Statement by Capt. Toshikazu Ohmae, Staff Officer (operations), First Mobile Fleet.
7. The various considerations which made the Philippines of central and primary importance in the formulation of Japan's defensive war plans in the summer of 1944 are set forth in the following interrogations made subsequent to the surrender by key staff officers of the Army and Navy Sections of Imperial General Headquarters:
8. (1) Daihonyei Rikugun Tosui Kiroku (Imperial General Headquarters Army High Command Record) 1st Demobilization Bureau, Nov 46, p. 210. (2) Statement by Col. Takushiro Hattori, Chief, Operations Section, Imperial General Headquarters, Army Section.
9. Slightly less probability was seen of a direct enemy invasion of Formosa or of the Ryukyu Islands, by-passing the Philippines. The homeland was rated third in order of probability, and the Kuriles last. (Ibid.)
10. (1) Hito Homen Kaigun Sakusen Sono Ichi (Philippine Area Naval Operations, Part I) 2d Demobilization Bureau, Aug 47, p. 7. (2) Statement by Col. Ichiji Sugita, Staff Officer (Operations), Imperial General Headquarters, Army Section.
12. On 29 June 1942, following the completion of the campaign to occupy the Philippines, the Fourteenth Army was removed from the command of Southern Army and placed directly under Imperial General Headquarters. Cf. Chapter VI, p. 113.
17. The labor recruiting program lagged so badly that, in the summer of 1944, President Laurel issued a proclamation reminding the Filipinos that they were obligated by the treaty of alliance with Japan to cooperate in the execution of defense measures. Despite this reminder, results remained unsatisfactory. (Statement by Maj. Mikio Matsunobe, Staff Officer (Intelligence), Fourteenth Area Army.
Ibid., Table No. 7.
21. Recent Situation in the Philippines, op. cit., pp. 7-8. American Editor's Note: These operations were carried out by clandestine sections of General MacArthur's intelligence system, i. e., the A. I. B. (Allied Intelligence Bureau) and P. R. S. (Philippines Regional Section). See G-2 Historical Section, GHQ FEC, General Intelligence Series: Vol. I, "The Guerrilla Resistance Movement in the Philippines" and Vol. II, "Intelligence Activities in the Philippines During the Japanese Occupation."
25. The 32d Division sailed from Shanghai in the Take convoy on 17 April together with the 35th Division destined for Western New Guinea. While the convoy was en route to Manila, Imperial General Headquarters suddenly decided to reassign the 32d Division to Second Area Army for the purpose of reinforcing Halmahera, and the division therefore did not disembark in the Philippines. On 28 April, an Imperial General Headquarters order formally transferred the 32d Division to Second Area Army and, in its place, assigned the 30th Division, then in Korea, to Fourteenth Army. (1) Imperial General Headquarters Army High Command Record, op. cit., pp. 230-1. (2) Dai Ni Homengun Dal Juyon Homengun Ido Hyo (Table of Movements of the Second and Fourteenth Area Armies).
26. (1) Nampo Gun Sakusen Kiroku (Southern Army Operations Record) 1st Demobilization Bureau, Jul 46, pp. 136-8. (2) Statement by Col. Kazuo Horiba, Chief, Operations Section, Southern Army. (3) Nampo Gun Sakusen Keikaku Taiko (Outline Policy of Southern Army Operation Plan) 1 May 44.
27. The term "area of general decisive battle" was used in a dual sense. First, it denoted Southern Army's intention to commit virtually all its strength in the Philippines in the event of enemy invasion, even at the cost of abandoning its commitments on other fronts within the Army's zone of responsibility. For the Southern Army this was considered the final decisive battle. Second, it was intended to convey the strategic concept of the Philippines as an area in which the Army and Navy would completely coordinate their forces in a general decisive battle. This latter concept became the central principle of the Sho-Go Operation plans elaborated by Imperial General Headquarters in July. (Statement by Col. Horiba, previously cited.)
28. If, prior to an attack on the Philippines, the enemy launched offensive operations on the Burma front or against the Palembang area, the main strength of the Fourth Air Army, conversely, was to be shifted to the western front to reinforce the Third Air Army. Southern Army Operations Record, op. cit., p. 137.
30. (1) Statement by Col. Horiba, previously cited. (2) Fourteenth Army, in an earlier estimate submitted to Imperial General Headquarters in March, had placed troop requirements for securing the Philippines at a minimum of seven field divisions, with 24 additional infantry battalions to maintain public order and combat guerrilla Philippine Operations Record, Phase Two, op. cit., p. 60.
31. For this purpose, Fourth Air Army headquarters was to be moved back from Menado to the Philippines to effect a reorganization of the Army's component air groups, using reinforcements to be sent out gradually from the Homeland. Southern Army Operations Record, op. cit., p. 138.
34. The east coast of Mindanao was regarded, at this time, as a probable landing point in case of enemy invasion of the Philippines. The 30th Division was therefore ordered to deploy its troops in the Surigao area when the division arrived in the latter part of May. (Statement by Lt. Gen. Gyosaku Morozumi, Commanding General, 30th Division).
36. Since early in 1944, the Navy had been preparing Tawitawi and Guimaras anchorages, in the Philippines, to accommodate major elements of the Combined Fleet in support of planned operations in the Marianas and Carolines areas. Preparations had also been started in March to establish facilities for accommodating command posts of the Combined Fleet and First Air Fleet at Davao. Philippine Naval Operations, Part I, op. cit., pp. 2-3.
39. The 26th Air Flotilla was assigned to the First Air Fleet on 5 May but did not participate in the Philippine Sea Battle of 19-20 June. Ago Sakusen ("Ago" Operations) 2d Demobilization Bureau, Aug 47, pp. 4, 20, 86-7.
42. Each air base consisted of several airfields, each of which was an integral part of the base. The advantages of this arrangement were; (a) closer and more effective coordination of defense measures; (b) more concentrated and efficient use of air strength; (c) better command and maintenance facilities. Bases varied in size from those capable of accommodating a full air division down to bases which could accommodate half a division. Imperial General Headquarters Army High Command Record, op. Cit., p. 206.
44. The 6th and 10th Air Brigades of the 2d Air Division moved forward to the Philippines in June, followed by the 7th and 13th during July and August. The 2d Air Division also assumed command of the 22d Air Brigade, already in the Philippines. Report on reinforcements sent to the Philippines, prepared by the 1st Demobilization Bureau in reply to memorandum of the United States Strategic Bombing Survey, 27 Oct 45. Submitted 14 Nov 45.
45. The 4th Air Division, upon its arrival, was assigned the primary mission of executing part of the airfield construction program. Two air reconnaissance companies, with about 20 aircraft, were assigned to the division, however, and allocated to anti-submarine patrol duty.
46. The organization of these new divisions differed from the standard Japanese infantry division in that each had two infantry brigades made up of four independent infantry battalions, with an approximate over-all strength of 10,000 troops. Rikugun Butai Chosa Hyo (Table of Army Units) War Ministry, 28 Oct 45, Part I, pp. 36-8.
49. Hito Sakusen Kiroku Dai Sanki Dai Nikan Furoku Reite Sakusen Kiroku (Philippine Operations Record, Phase Three, Vol. II, Supplement: Leyte Operations Record) 1st Demobilization Bureau, Oct 46, pp. 9-10.
51. The other major elements of the First Air Fleet at the end of June were: 22d Air Flotilla, stationed on Truk; 23d Air Flotilla, which had been transferred from the control of the Southwest Area Fleet on 5 May and was deployed in the Ceram-Halmahera area; and the 26th Air Flotilla, which was still at Davao. The 62d Air Flotilla had been organized in Japan and assigned to the First Air Fleet early in 1944. Just before the Philippine Sea Battle in June, it was transferred temporarily to direct Combined Fleet command. "Ago," Operation, op. cit., pp. 11-14.
53. Southwest Area Fleet had previously made preparations to transfer its headquarters to Kendari, in the Celebes, or to Halmahera, in order to facilitate support of operations in Western New Guinea. With the invasion of Hollandia, however, these plans were cancelled in favor of a transfer to Manila. Ibid., pp. 28-9.
62. Since 1943 some fortification work had been done on airfields within the national defense sphere. Concrete revetments had been constructed to protect fuel and ammunition and control installations. Efforts were now renewed to complete this work in the Philippines. (Statement by Col. Sugita, previously cited.)
63. The Zuikaku, of about 29,800 tons, was the only regular carrier remaining. The Chiyoda, Chitose, Zuiho and Ryuho, all with an approximate tonnage of 14,000, had been converted from seaplane and submarine tenders and were classed as light carriers. The Junyo, 27,500 tons, was a converted merchant ship. The Ise and Hyuga, converted from battleships, had no flight decks and carried only 22 aircraft which were launched by catapult. (1) Kakukan Kozokuryoku To Ichiranhyo (Table Showing Radius of Action of Naval Ships) 2d Demobilization Bureau, 19 Jul 47, p. 3. (2) Japanese Naval Vessels at the End of the War, 2d Demobilization Bureau, Apr 47, p. 2.
64. The size, structure, and armament of the Musashi and Yamato were one of the Japanese Navy's most closely guarded secrets. The five other battleships of the fleet included two old, slow-speed ships, the Fuso and Yamashiro. The Fuso had participated in naval actions since early 1944 under direct Combined Fleet command. On 10 September, it was assigned together with the Yamashiro to the Second Battleship Division. Philippine Naval Operations, Part II, op. cit., p. 37.
70. The First Air Fleet had under its command the 15th Air Regiment (Army), which was attached on 16 May 1944 to assist in long-range reconnaissance. (1) Daikaishi Dai Sambyakushichijuku-go (Imperial General Headquarters Navy Directive No. 379) 16 May 44. (2) Teraoka Nikki (Diary of Vice Adm. Kimpei Teraoka) First Air Fleet Commander.
73. Much discussion had centered around the most desirable division of operational responsibility in the Philippines. In view of the political and strategic importance of Luzon, it was decided that one Army should control that key island. On the other hand, the central and southern Philippines not only were closely interrelated topographically but also were expected to be the target of the initial Allied invasion. Decision was therefore reached to assign the responsibility for securing that sector to another Army. Finally, Imperial General Headquarters concluded that it would be desirable to have a single headquarters maintain unified command over the entire Philippine area, thus retaining maximum flexibility in the employment of ground forces and facilitating necessary coordination between the air and ground forces. To fulfill this mission it was decided forthwith to raise the status of the Fourteenth Army to that of an Area Army with additional responsibility for the direct defense of Luzon. (1) Imperial General Headquarters Army High Command Record, op. cit., pp. 278-9. (2) Philippine Operations Record, Phase Two, op. cit., pp. 63-4. (3) Philippine Operations Record, Phase Three, op. cit. Vol. I, pp. 22-3.
74. The 1st Division, stationed in North Manchuria, was reorganized on 24 July and began moving to Shanghai on 20 August, completing its movement in early September. Dai Ichi Shidan Sakusen Kodo Gaiyo (Summary of Operations, 1st Division) Home Depot Bureau, 1 Mar 47, p. 6.
75. In addition to the provisions of the basic Sho-Go plan, an important amendment was inclusion of the Moluccas in the strategic scheme for the defense of the Philippines. Lt. Gen. Numata, who attended the 5 August conference, urgently recommended that this area be regarded as a vital outpost and appropriately reinforced, particularly with air contingents. This recommendation was adopted by the conference, and plans were subsequently made to furnish substantial air reinforcements to the Halmahera area. (Interrogation of Lt. Gen. Takazo Numata, Chief of Staff, Second Area Army.)
80. These missions were set forth in a separate annex to the order. The original text of this annex is not available, but the essential portions paraphrased in this volume were reconstructed from the following sources: (1) Combined Fleet Top Secret Operations Order No. 84, 1 Aug 44; Task Force Top Secret Operations Order No. 76, 10 Aug 44; Second Striking Force Top Secret Operations Order No. 1, 10 Aug 44. ATIS Limited Distribution Translation No. 39, Part VIII, 4 Jun 45, pp. 226-33; Part I, 22 APR 45, pp. 3-8; Part V, 28 May 45, pp. 5-11. (2) Philippine Naval Operations Part I, op. cit., pp. 14-19. (3) Statement by Comdr. Saku Mikami, Staff Officer (Operations), Imperial General Headquarters, Navy Section.
82. Original text of the operational outline annexed to Combined Fleet Top Secret Operations Order No. 85 is not available. The substance of this outline relating to surface force operations is given here on the same sources as listed in n. 80.
83. The outline further contained a paragraph regarding the employment of surface special attack forces. This paragraph provided that the use of such forces would be subject to direct control by Imperial General Headquarters, and that the latter would issue a special order for their employment in combat. Philippine Naval Operations, Part I, op. cit., p. 21.
85. Concurrently with these military and naval preparations, steps were taken to assure coordinated action on the political and diplomatic fronts. An Imperial conference held on 19 August called for a thorough mobilization of national strength by the end of the current year and for decisive action to improve the Empire's diplomatic position. (Statement by Col. Hattori, previously cited.)
86. The 2d Air Division had 400 planes, and the 4th Air Division (mostly base maintenance personnel) about 20. The 7th Air Division operating in the Second Area Army zone had about 70 planes. The 6th Air Division had remained inoperational since losing its last strength at Hollandia and was finally deactivated on 19 August. (1) Philippine Air Operations Record, Phase Two, op. cit., pp. 25-6. (2) Dairikumei Dai Senhyakugo-go (Imperial General Headquarters Army Order No. 1105) 19 Aug 44.
87. Principal units assigned to the 2d Air Division at the end of August were: 6th Air Brigade (65th and 66th Fighter-Bomber Regiments); 7th Air Brigade (12th and 62d Heavy Bomber Regiments); 10th Air Brigade (27th and 45th Fighter-Bomber Regiments); 13th Air Brigade (30th and 31st Fighter Regiments); 22d Air Brigade (17th and 19th Fighter Regiments); 2d Air Regiment; one squadron, 28th Air Regiment and 31st Independent Reconnaissance Squadron. Philippine Air Operations Record, Phase Two, op. cit., pp. 22-3.
89. Principal units operating under the 7th Air Division at this time were: 3d Air Brigade (13th Fighter Regiment and 75th Light Bomber Regiment); 9th Air Brigade (24th Fighter Regiment and 61st Heavy Bomber Regiment); two reconnaissance squadrons. (1) Ibid. (2) Philippine Air Operation Record, Phase Two, op, cit., p. 23.
91. (1) Ibid., pp. L-31-3. (2) Teikoku Kaigun Senji Hensei (Wartime Organization of the Imperial Navy) Navy General Staff, Vol. II, 15 Aug 44, p. 32. (3) At the same time the service units of the 26th Air Flotilla had been organized as the Philippines Airfield Unit.
99. (1) Philippine Air Operations Record, Phase Two, op. cit., pp. 5-8, 14-15, 33-9. (2) Dai Roku Kichi Koku Butai Meirei Saku Dai Roku-go Bessatsu (Supplement to Sixth Base Air Force Operations Order No. 6) 5 Sep 44. (3) Hito Homen Koku Sakusen ni kansuru Riku-Kaigun Genchi Kyotei (Army-Navy Local Agreement Concerning Philippines Air Operation) 1 Sep 44.
100. This Table of Assignments specified the types of Army and Navy aircraft to be employed for different purposes. Against enemy carriers, the Army Air force was to use only the Type IV bomber, while the Navy was to employ both land-based and carrier-borne bombers, torpedo planes and fighters. Against enemy transports, a variety of Army as well as Navy planes was to be used. Philippine Naval Operations, Part I, op. cit., pp. 15-6.
102. The 3d Carrier Division was reorganized on 10 August to consist of the carriers Chiyoda, Chitose, Zuiho and Zuikaku, with the 634th Air Group. The 4th Carrier Division was assigned the Ise, Hyuga, Junyo and Ryuho, with the 654th Air Group. Ibid.
103. Battleships were armed with 120 25-mm automatic cannons, cruisers with 80, and destroyers with 40. These numbers represented an increase of six to ten times the numbers of automatic cannon mounted on combat vessels during operations in the Solomons in 1942. Ibid., p. 37.
104. Transports carrying one infantry battalion of the 26th Division and one infantry battalion, three tank companies, and three artillery batteries of the 2d Armored Division were sunk by submarine attack during these movements. Philippine Operations Record, Phase Three, op. cit. Vol. I, p. 78 (chart).
107. Responsibility for the defense of Batan Island was assigned to Southern Army on 1 September. Prior to that date, the operational boundary between the Southern Army and the Formosan Army ran between the Batan and Babuyan Islands, only the latter falling within Southern Army's zone. Dairikumei Dai Senhyakujuyon-go (Imperial General Headquarters Army Order No. 1114) 26 Aug 44.
110. This represented a modification of earlier estimates by Fourteenth Area Army. Strong probability was previously seen of a direct invasion of Luzon by American forces advancing from Saipan. (Interrogation of Col. Kobayashi, previously cited.)
112. At the end of September, the status of the major airfield projects in the central and southern Philippines was as follows: The base at Bacolod, on Negros Island, was already completed, but because of poor drainage, its use could not be depended upon in the rainy season. The projected fields at Burauen, on Leyte, were about 90 per cent completed, while those at Davao and Del Monte, on Mindanao, were about 70 and 80 per cent completed, respectively. Ibid., pp. 9-10.
115. When the 16th Division was assigned to the Leyte-Samar area in April, headquarters and two battalions of the 9th Infantry Regiment were stationed on Samar. In July the regimental headquarters and one battalion were ordered back to Leyte, leaving only one battalion on Samar. 2d Battalion/9th Infantry Operations Order No. 97, 22 Jul 44. ATIS Bulletin No. 1656, 28 DEC 44, p. 13.
116. At the time he assumed command, Lt. Gen. Suzuki estimated that the most probably target of the enemy's initial assault would be Davao, with the beaches along Leyte the next most likely landing spot. Philippine Operations Record, Phase Three, op. cit. Vol. II Supplement, pp. 7, 21-2.
120. These coastal defenses consisted of a series of strong points built at strategic points along the coast between Palo and Abuyog. Lt. Gen. Makino,16th Division commander, ordered key emplacements to be constructed strongly enough to resist 15-cm howitzer shells.
121. This overall tonnage was broken down as follows: 300 rounds per rifle; 20,000 rounds per machine gun; 10,000 hand-grenades per division; 300 rounds per "knee" mortar; 1,500 rounds per 7.5 cm artillery piece. (Statement by Col. Ryoichiro Aoshima, Staff Officer (Line of Communications), Fourteenth Area Army.)
122. (1) Philippine Operations Record, Phase Three, op. cit. Vol. II Supplement, pp. 25-6. (2) Fourteenth Area Army Operations Orders. Published in XXIV Corps ADVATIS Translation XXIV CAET No. 7, 12 Nov 44. (3) Thirty-fifth Army Operations Orders. XI Corps ADVATIS Translations No. 38, 14 Jan 45.
123. The 166th Independent Infantry Battalion of the 100th Division, stationed around Cotabato, was not pulled back to Davao, but was transferred to 30th Division command and remained in the vicinity of Cotabato. (Statement by Col. Muneichi Hattori, Chief of Staff, 100th Division.)
124. The 55th Independent Mixed Brigade moved first from Luzon to Cebu, re-embarking there for Jolo. The last elements of the brigade reached Jolo on 5 October. (Statement by Maj. Tokichi Temmyo, Commander, 365th Battalion, 55th Independent Mixed Brigade.)