The japanese road to singapore japanese perceptions of the singapore naval base, 1921 41 7

Chapter The Road to Singapore 1940-41 Since Britain was included in the hypothetical enemies list of the Teikoku Kokubō Hōshin of 1936, the Operations Sections of the General Staffs began their studies for making their operational plans against Britain. From 1939 onwards, they proposed their operational plans annually to Emperor Hirohito, which included operational plans for attacking British Malaya and Singapore. However, making operational plans did not mean Japan decided to attack British Malaya and Singapore. Even though the two General Staffs presented operational plans annually, Japan did not have the intention of waging war against Britain. In fact, Japan did not examine even the possibility of opening hostility against Britain until Germany dominated continental Western Europe in the summer of 1940. On September 1939, the Second World War broke out with the German invasion of Poland. In May and June 1940, the Germany Blitzkrieg conquered the Netherlands, Belgium and France. France capitulated to Germany on 22 June 1940. Colonial masters of the Dutch East Indies and the French Indochina were in desperate straits. Norway, Denmark, the Netherlands, Belgium and France were occupied by Germany. This situation in Europe affected Japanese decision makers greatly. The Imperial Japanese Army for the first time in its history turned its eyes to the south. For the eyes of the Imperial 197 Japanese Army, Singapore appeared as the most important military target in the south. One and half years later, the Second World War in the Asia-Pacific region broke out with simultaneous Japanese attacks on British Malaya, the Philippines and Hawaii. In retrospect, it could be said, without the Second World War in Europe, Japan would not have attacked Singapore. This chapter examines the history from the outbreak of the Second World War in Europe in September 1939 to the outbreak of the war in the Asia-Pacific region in December 1941. In particular, it analyses the following four aspects. First, how did the Japanese react to the outbreak of the Second World War in Europe. Second, how did the Japanese government decide to wage war against Anglo-American powers. Third, how did the Imperial Japanese Army prepare to attack British Malaya and Singapore. Fourth, why Japan attacked British Malaya and Singapore? Influence of the European War on Japan Since the Teikoku Kokubō Hōshin (Imperial National Defence Policy) was first sanctioned in 1907, Russia (the Soviet Union) had always been the principal hypothetical enemy of the Imperial Japanese Army. The conclusion of the German-Japanese Anti-Comintern Pact in 1936 and the outbreak of the Sino-Japanese War in the following year increased tension between Japan and the Soviet Union. The Japanese turned their eyes on the Soviet Union as the backer of the Chinese Nationalists. On 29 July 1938, there occurred skirmishes between the Imperial Japanese Army (the Chosen Army of Japan, 19th Division) and the Soviet Army in Changkufeng, an area in southern Manchuria 198 that bordered both on the Soviet Maritime Province and Korea. Small-scale fighting ensued and there was a truce on 11 August in Moscow before it was enlarged. This was an insignificant event in itself but showed Japanese army’s military unreadiness.1 In 1939, there were a number of border disputes between the Soviet-backed Outer Mongolia and Manchukuo. From May onwards, they were escalated into Soviet bombing raids and Kwantung Army’s air attacks, which were not authorised by the Army General Staff, over the obscure border. At that time, general consensus of the Army General Staff was that, as long as the war in China lasted, Japan was in no position to engage in an all-out war against the Soviet Union. But adventurous middle-echelon officers of the Kwantung Army, Captain Tsuji Masanobu and Lieutenant-Colonel Hattori Takushirō, did not share this view and were eager to strike a heavy blow at the Soviet Union. On July, Japanese infantry of the Kwantung Army crossed the border into Mongolia but was checked by the Soviet forces. On 23 July, the Kwantung Army tried again but was checked again. On 20 August, the Soviet forces, led by General Zhukov, launched a massive surprise offensive known to the Soviet as the Kalkhin-Gol Battle and to the Japanese as the Nomonhan Incident. By the end of August, the Russian had completed what they described as the most impeccable encirclement of an enemy army since Hannibal beat the Roman at Cannae in 216 BC. The 23rd Division of the Kwantung Army was virtually wiped out. At least 18,000 Japanese was killed Akira Iriye, The Origin of the Second World War in Asia and the Pacific (London: Longman, 1987), pp.61-62. 199 in this battle.2 Tsuji’s act of blind courage would work well in Malaya in later days, but brought disaster to the Kwantung Army in Nomonhan. While the Kwantung Army engaged in a life-and-death struggle against the mighty Soviet Army in vast plains in the Mongolia-Manchuria border zone, news from Europe gave Japanese leaders a shock. German and the Soviet Union concluded the German-Soviet Nonaggression Pact on 23 August. For Japanese leaders, especially for the army, the German’s conclusion of the German-Soviet Nonaggression Pact was hard to comprehend, and an act of disloyalty.3 Because, until then, the army had regarded German as a partner to confront the Soviet Union. Almost overnight, the army’s plan for seeking alliance with German to confront the Soviet Union vanished in smoke, at least temporarily. Prime Minister Hiranuma Kiichirō threw up his job on 28 August with issuing the famous statement: “conditions in Europe are messed up beyond all recognition”. Until then, he was torn between conflicting demands of the two armed forces: the army advocated alliance with German to confront the Soviet Union while the navy opposed it because the navy considered it would bring Japan into conflict with the United States. General Abe Nobuyuki was appointed as the new Prime Minister on 30 August. His new government started every effort to end hostilities thought diplomatic channels. On the same day, Vice-Chief of the Army General Staff, Lieutenant-General Nakajima Tetsuzō, flied to Manchuria to rein the Sumio Hatano “Japanese-Soviet campaigns and relations, 1939-45.” in the Oxford Companion to the Second World War (Oxford: Oxford University Press, 1995), pp.634-637. Chihiro Hosoya, Ryōtaisenkan No Nihon Gaikō 1914-1945 (Japanese Diplomacy in the Inter War Period 1914-1945) (Tokyo: Iwanami Shobō, 1988), pp.142-143. 200 Kwantung Army. On September, the war in Europe broke out by German invasion of Poland. The Abe Government adopted a non-intervention policy in Europe, which gave priority to settlement of the Sino-Japanese War, emphasising that Japan must aim to make third parties stop assisting the Chinese Nationalists. This policy was endorsed by the Minister of Foreign Affairs, the Minister of War and the Minister of the Navy in late 1939. On the other hand, the outbreak of the European war convinced Moscow of the need to come to an agreement with Japan. Accordingly, the Japanese Ambassador to the Soviet Union, Tōgō Shigenori, and the Soviet Foreign Minister, Molotov Vyacheslav, arranged a cease-fire that became effective on 16 September.4 By the Nomonhan Incident and the conclusion of the German-Soviet Nonaggression Pact, the army lost confidence, so that the voice of the army within the Japanese government became weaker for a while.5 Even though the army did not abandon its north-bound policy, its conviction for it lost strength.6 Some in the Ministry of Foreign Affairs and a small number of officers in the Army General Staff even explored possibility of rapprochement with the Soviet Union, but a majority view of the Army General Staff did not support it.7 The Abe Government’s non-intervention policy to European war was followed by the Yonai Mitsumasa Government, which took power in January 1940.8 Sumio Hatano “Japanese-Soviet campaigns and relations, 1939-45.” Hosoya, Ryōtaisenkan No Nihon Gaikō 1914-1945, p.143. Alvin D. Coox, Nomonhan: Japan Against Russia, 1939, Volume (Stanford: Stanford University Press, 1985), pp.1028-1032. Hosoya, Ryōtaisenkan No Nihon Gaikō 1914-1945, pp.195-215. Kiyoshi Ikeda, “The Road to Singapore: Japan’s View of Britain, 1922-41” in T.G. Fraser and Peter Lowe (eds.), Conflict and Amity in East Asia: Essays in Honour of Ian Nish (Basingstoke: Macmillan Press, 1992), p.41. 201 The German Blitzkrieg to the Low Countries in May 1940 changed the situation drastically. It dazzled the Imperial Japanese Army. Army officers, having been depressed since the debacle in Nomonhan and the conclusion of the German-Soviet Nonaggression, were rejuvenated by the new situation in Europe. One day in late in May, Chief of Army Affairs Section of the Ministry of War, Colonel Iwakuro Hideo told Chief of the Operations Section of the Army General Staff, Colonel Okada Jūichi: “For a while, it is important for the army to focus on settlement of the war in China, but the world situation drastically changed, so we have to start studies and preparations on the south just in case they become necessary. Has the Army General Staff started preparations?” On the following day, there was a discussion in the Operations Section of the Army General Staff over whether Japan should advance to the south to capture natural resources areas or not. Some claimed it would be necessary to it in order to settle the war in China. Some claimed it was not good to commence another war because it would lead Japan to dispersing its resources and forces. There was no conclusion to this discussion, but they agreed to make operational plans which would include operational plans in the Dutch East Indies.10 The Imperial Japanese Army for the first time in its history turned its eyes to the south. France capitulated to Germany on 22 June. Two days before, the French authorities in Indochina agreed to a Japanese request to stop the transit BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. (Imperial General Headquartes The Army Department, Vol. 2) (Tokyo: Asagumo Shinbunsha, 1968), pp.47-48 BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2., 47-48; Akira Iriye, The Origin of the Second World War in Asia and the Pacific (London: Longman, 1987), p.102. 10 202 of war supplies to the Chinese Nationalists. Before that, from late May to early June, a senior member of the Army Affairs Bureau of the Ministry of War, Lieutenant-Colonel Nishiura Susumu, by an order of Colonel Iwakuro drafted a plan called “Guidance Plan for War in the South”. The contents of it were: (1) The war will start with a surprise attack. (2) We make policies on the assumption that the United States and Britain are separable. We will keep an eye on the Philippines, but will not attack them unless it becomes unavoidable. (3) We will attack Singapore, and after that, will attack and occupy the Dutch East Indies. For these purposes, we will consider using French Indochina and Thailand as advanced air bases. (4) We will attack Hong Kong when necessary. (5) If possible, we will separate Britain from the Netherlands. In this case, we will not attack Singapore. We will make a surprise attack directly on the Dutch East Indies and occupy natural resources areas. (6) For these operations, we will use several divisions.11 This plan shows us three important things. First, capturing natural resources areas in the Dutch East Indies was the main purpose of the supposed war in the south. Second, to capture natural resources in the Dutch East Indies, Japan had to attack Singapore. Singapore appeared as the most important military target in the south, because Singapore was the principal military base BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2., p.48. Nishiura himself was the editor of Senshi Sōsho. This part was written on his memories. 11 203 of Anglo-Dutch powers in the region. Third, war against the United States should be avoided as much as possible unless it became unavoidable. It was reasonable to limit the number of enemies as much as possible. After Germany dominated the Low Countries and France in June, there was an illusion in Japan, especially among army officers, that the fate of Britain was like a candle before the wind. What occupied the interest of army officers was the future of European colonies in Asia. As a defeat of France became definitive, south-bound policies obtained support quickly. At a conference on 24 June, Colonel Iwakuro astonished members of the Army General Staff by suddenly presenting his view of the necessity of a surprise attack on Singapore. 12 With regard to the Imperial Japanese Army, the south-bound policy was south-bound advancement to the Dutch East Indies and British possessions in Asia for capturing natural resources. There was oil in the Dutch East Indies, and rubber and scarce metals in British Malaya. To acquire natural resources in the Dutch East Indies and British Malaya, the army had to conquer their principal military bases. Accordingly, Singapore appeared as the army’s most important military target in the south. This was how Britain became the principal adversary of the Imperial Japanese Army. In the meantime, the Imperial Japanese Army also considered it would be best to readjust Japanese relations with the Soviet Union through a non-aggression pact. But the Minister of Foreign Affairs, Arita Hachirō, feared that it would result in a further deterioration of Japan’s position vis-à-vis Ichiji Sugita, Nihon no Sei-Senryaku to Kyōkun (Japanese Strategy and Lesson of It) (Tokyo: Hara Shobō, 1983), p.244; Chihiro Hosoya, “The Tripartite Pact” in James William Morley (ed.), Deterrent Diplomacy: Japan, Germany and USSR 1935-1940 (New York: Columbia University Press, 1976), p.207. 12 204 Britain and the United States. As a result, Japanese military and civilian officials concluded that the best alternative would be a treaty of neutrality between Japan and the Soviet Union. They considered political ties by a treaty of neutrality were weaker and less hostile to Britain and the United States than those by a non-aggression pact. Such an arrangement would ensure Soviet neutrality in the event Japan became involved in a conflict with the Anglo-American powers, while at the same time putting an end to Soviet assistance to China.13 However, this policy did not materialise until 13 April 1941. On July, a handful of middle-echelon officers of the Ministry of War and the Army General Staff drafted a policy, “Outline of the Main Principles”, based on the Nishiura paper “Guidance Plan for War in the South”. It revealed their impatience to take advantage of the war in Europe, and to resort to the use of force against French Indochina and, depending on the circumstances, against the Dutch East Indies also. They considered that, if Britain were defeated, or if the United States entered the war in Europe with little strength to spare in the Pacific, the great opportunity for south-bound military advancement would arise.14 This depended upon an assumption that Britain and the United States could be separated strategically. The “Outline of the Main Principles” stated that, in case of south-bound military advancement, military targets should be limited to French Indochina, Hong Kong, British Malaya and the Dutch East Indies. As for the United States, it stipulated, “A war with the United States should be avoided as much as possible, although 13 14 Iriye, The Origin of the Second World War in Asia and the Pacific, p.102. Asada, From Mahan to Pearl Harbor, p.237. 205 preparations must proceed in anticipation of a probable military clash”. It also mentioned strengthening relations with Germany and Italy.15 On the following day, there was a meeting between the two armed forces, in which the army submitted the “Outline of the Main Principles”. Representatives from the navy were pleasantly surprised by the army’s swing from its traditional Hokushin Nanshu Ron (Advance to the North, Hold in the South Policy” to Hokushu Nanshin Ron (Hold in the North, Advance to the South Policy). But the navy had to point out the crucial defect of the “Outline of the Main Principles”. It did not consider relations with the United States seriously enough. South-bound military advancement without seriously considering the possibility of waging war against the United States was too dangerous for the navy to accept. In the army’s assumption, Japanese military advancement to the south would not necessarily bring a clash with the United States, but the navy emphasised the “inseparability” of Britain and the United States.16 After the Russo-Japanese War, the Imperial Japanese Navy always regarded the United States as its principal hypothetical enemy. What the navy cared about at that time was the American Pacific Fleet, which had been stationed at Pearl Harbour since April that year, and the American naval expansion programme. The only naval force which had the capability to confront the Imperial Japanese Navy in the Asia-Pacific region was the American Pacific Fleet. BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. , pp.49-51; Nihon Kokusai Seiji Gakkai (Japanese Association of International Relations) (ed.), Taiheiyō 15 Sensō e no Michi: Bekkan Shiryōhen (The Road to the Pacific War: Supprementary Volume of Documents) (Tokyo: Asahi Shinbunsha, 1988), pp.315-318; Iriye, The Origin of the Second World War in Asia and the Pacific, p.102. Taiheiyō Sensō e no Michi: Bekkan Shiryōhen, pp.315-318; Asada, From Mahan to Pearl Harbor, p.237. 16 206 He observed that the weather of Malaya was less hot than he had anticipated, and British, Indian and Australian defence forces were not formidable. The north coasts of Singapore Island were almost defenceless, so the key to attacking Singapore was how to advance down the Malay Peninsula. The parts of the investigation that the Army General Staff appreciated most were those illustrating the sheer size of the peninsula, the number of rivers and bridges, and the narrowness of the roads which criss-crossed jungles. As the retreating enemy would certainly destroy the 250 bridges that crossed the rivers of varying sizes on the route to Singapore, it was essential to have the capacity to rebuild them quickly. Among them, how to cross Perak River, the width of which was approximately 300 metres, would be the key. In addition, on the routes to Singapore, attacking the enemy from both flanks would be difficult in view of the fact that dense jungle grew on both sides of roads. Consequently, breakthrough advancement with a sudden and overwhelming display of firepower and motorised superiority was essential.115 As the Army General Staff amassed its knowledge on the Malay Peninsula, the investigation on Malay Peninsula became more practical. The results of these investigations were reflected in the training, formation, and equipment of the Army units engaged in the Malaya Campaign. To prepare a real operational plan for war, the two General Staffs would have to make a comprehensive one. As we saw previously, in peace time, each the Army General Staff and the Navy General Staff made its Teruto Kunitake, “Marē Sakusen wa Kaku Keikaku Sareta (How did we make plans for the Malaya Campaign)” in Maru (April, 1958), 36-41; Tohmatsu, “The Imperial Army Turns South: the IJA’s Preparation for War against Britain, 1940-1941”, pp.178-179. 115 256 operational plan annually and submitted it to the Emperor. These Annual Operational Plans included their operations plans for each theatre. But there was no integrated operational plan which integrated operations in every supposed theatre. Also, coordination between the army’s operational plan and the navy’s operational plan were not fully adjusted. After deciding to postpone war against the Soviet Union on August 1941, the Army General Staff turned its attention to the south. The Army General Staff had already started planning to attack the south on the assumption that the United States, Britain and the Netherlands were inseparable.116 Facing the de facto oil embargo, the Army General Staff finally accepted the inseparability of the United States and Britain. To capture natural resources in the south, Japan would attack both the United States and Britain. In the meantime, the Navy General Staff also started preparing its plan to attack south after the American de facto oil embargo.117 At that time, however, there was no agreement between the two General Staffs over their supposed integrated operational plans. The Army General Staff assumed in mid-August of 1941 that operations in the south should finish by May 1942. In the first stage, it would attack Hong Kong, British Malaya, British Borneo, the Philippines and Guam simultaneously, and then, in the second stage, occupy the Dutch East Indies. The most important theatre was British Malaya and Singapore. On the other hand, the Navy General Staff supposed: for the first stage, its own air forces would attack the Philippines and army air forces would attack British Malaya to annihilate the 116 117 BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. , p.383. BBKS, Senshi Sōsho, Daihon’ei Kaigunbu, Rengō Kantai, 1: Kaisen Made (The Imperial Headquarters, Navy Combined Fleet, Vol. 1, Up to the Outbreak of Hostility), (Tokyo: Asagumo Shinbunsha, 1975), pp.551-552. 257 enemy’s air power, and then Japan would land troops first in the Philippines, second in Borneo, third in Java, fourth in Sumatra and finally in British Malaya. The army’s main forces would land in the Philippines. According to the navy’s plan, it would take five months before Japan occupied Singapore. Chief of the Operations Division of the Army General Staff, Tanaka Shin’ichi, considered that the navy’s plan which would leave British Malaya without landing Japanese forces for so long was too risky. There was a possibility that conditions in Thailand and French Indochina would become unstable during this period. In the army’s plan, to attack Singapore was the most important military objective, while in the navy’s plan, to annihilate American air power in the Philippines was the most important. In other words, Singapore’s priority was not high in the navy’s plan and it left the work to the army. The plan of attacking British Malaya and Singapore did not inspire enthusiasm in the navy, because the navy focused its attention on how to annihilate American forces in the Philippines. In addition, in the Imperial Japanese Navy, the Combined Fleet was preparing plans to attack Hawaii for itself. 118 Consequently, planning operations to attack British Malaya and Singapore was conducted principally by the Army General Staff. On 14 and 15 August, the map manoeuvre to attack the south was conducted by the Army General Staff. Staff officers from the Operations Section of the Navy General Staff also participated. It was carried out based on the army’s plan, in which they realised how they saw operations in the south BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. , pp.381-391; BBKS, Senshi Sōsho: Daihon’ei Kaigun-bu, 1. , 551-552; BBKS, Senshi Sōsho: Marē Shinkō Sakusen, pp.38-40. 118 258 differently. In addition, for both navy staff officers and army staff officers, operations in the south were subordinate parts of their supposed war. The main theatre for the navy was the Pacific Ocean while the army supposed that, after finishing operations in the south, it would re-mobilise its forces to the north in the spring of 1942. In the Army General Staff, General Sugiyama ordered his staff on 16 August to study how to mobilise forces to the north after finishing operations in the south.119 On 22 August, the Navy General Staff sent its operational plan for the south, including the plan to attack Hawaii which had been prepared by the Combined Fleet, to the Army General Staff. The Navy General Staff conducted map manoeuvres from to September. Commander Yamamoto Yūji informed to Lieutenant-Colonel Imoto Kumao of the result on 10 September. As for operations for convoying the army’s units to land on the Malay Peninsula, Yamamoto Yūji explained to Imoto that, in the first stage, the advanced units would be landed only in southern Thailand. Then, several (around five) days later, the main force would be landed in Kota Bharu.120 The Navy General Staff and the Combined Fleet judged that simultaneous landings in southern Thailand and Kota Bharu were too dangerous in view of the fact that Japanese forces would land in the face of the enemy. Kota Bharu was in British Malaya and there was an airfield on which Britain might deploy fighters and torpedo bombers. The navy could not guarantee safe landing.121 After the Imperial Conference adopted the “Essentials for Carrying Out the Empire’s Policies” on September 1941, the Army Department of BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. , pp.391-392. Ibid., pp.480-481. 121 BBKS, Senshi Sōsho, Marei Shinkō Sakusen (The Malaya Campaign) (Tokyo: Asagumo Shinbunsha, 1966), p.41. 119 120 259 Imperial General Headquarters (the Army General Staff) formally ordered preparations for war on 18 September. Accordingly, it assigned charge to its staff. Lieutenant-Colonel Imoto Kumao, who had observed British Malaya and Singapore in 1939, took charge of drawing up operational plans for the southern theatres: British Malaya, the Philippines and the Dutch East Indies. Under him, Captain Kunitake Teruto, who had observed the Malay Peninsula earlier that year, took charge of drawing up operational plans to attack British Malaya and Singapore. Tsuji Masanobu, who had been in the Taiwan Army Intelligence Unit earlier that year, took charge of supervising logistics plans. These three officers who had a better knowledge of British Malaya and its tropical climate than other staff were directly involved in drawing up operational plan for attacking British Malaya and Singapore.122 They had already devoted themselves day and night from early September to this by integrating and refining operational plans in the “Annual Army’s Operational Plan for 1941”. They realised it was difficult to land in Mersing from Intelligence report dated in September 1941. It reported that Britain was strengthening defences on routes－ Mersing to Kluang and Mersing to Kota Tinggi－by establishing pillboxes and completing preparations for destroying roads and bridges and the Britain authorities announced on 25 February that it would place naval mines along the east coast of the Malay Peninsula between degrees, 44 minutes north latitude and degree, 35 minutes, 80 seconds north latitude, which included Mersing, Endau and the mouth of Sungai Sedili Besar. 123 By the end of September, they completed their work. On 23 122 123 BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. , pp.465-468. NIDS, Army Documents, Nansei-Zenpan-172, “Eiryō Marei Jōhō Kiroku 260 September, a member of Operations Section, Major Katō Shōhei, returned from Saigon, where the 25th Army was stationed, reporting that the 25th Army was demoralised, so that it had to reshuffle its staff officers. Officers of the 25th Army did not consider war was imminent and enjoyed their life in the tropics.124 Accordingly, after finishing his work in the Army General Staff, Tsuji was transferred to Saigon to raise morale and promote preparations by the 25th Army. He arrived in Saigon on October. The Army General Staff conducted map manoeuvres in the Army Staff College from October to October. In these map manoeuvres, Japan occupied Singapore on the 95th day after the outbreak of war.125 By the end of October, Kunitake Teruto was also transferred to Saigon as a staff officer of the 25th Army. Hence, finalisation of the operational plan for attacking British Malaya and Singapore was carried out by staff officers of the 25th Army. Meanwhile, the Navy General Staff decided to attack Hawaii on 20 October with all six aircraft carriers of the Imperial Japanese Navy.126 By this decision, it became clear that Japan should attack south without an aircraft carrier. Already in the early October, the army confiscated, rigged and armed around 126, 000 tons of merchant vessels for convoying its forces in operations in the south.127 On 29 October, the Army General Staff completed the “Imperial Army’s Operational Plan Against the United States, Britain and the Netherlands”. Around that time, the Navy General Staff also completed the (Intelligence Report on British Malaya)”, dated on 20 September 1941. BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2. , pp.482-483; Tsuji, Japan’s Greatest Victory and Britain’s Worst Defeat, pp.21-22. 125 BBKS, Senshi Sōsho: Daihon’ei Rikugun-bu, 2., pp.482-488. 126 Ibid., p.541. 127 Ibid., pp.468-472. 124 261 “Imperial Navy’s Operational Plan Against the United States, Britain and the Netherlands”. The two General Staffs jointly explained them to the Emperor on and November, and after the Imperial Conference on November, which approved the new “Essentials for Carrying Out the Empire’s Policies”, both plans were approved by the Emperor. 128 On November, Lieutenant-General, Yamashita Tomoyuki, was appointed the Commander of the 25th Army and General Terauchi Hisaichi was appointed the Commander of the Southern Army. Strategic differences between the two armed forces were adjusted on November by “The Army and Navy’s Southern Strategy Agreement”, which stated that both British Malaya and the Philippines would be swiftly attacked. The object of this military movement in the south was to destroy and occupy American, British and Dutch bases in the Philippines, Guam, Hong Kong, British Malaya, Burma and the Dutch East Indies. Main forces of the army would attack British Malaya while main forces of the navy would attack the Philippines. The army placed the highest priority on operations in British Malaya and Singapore. The newly adopted device of spare petrol-tanks enabled the Imperial Japanese Navy’s Zero fighters to fly all the way from southern Taiwan to the Philippines. The navy, because of strong demand from the army, agreed to use 27 Zero fighters and reconnaissance planes to cover the landing forces on the Malay Peninsula. In exchange, the army agreed to remove one Air Squadron from Manchuria and deploy it for operations in the Philippines.129 128 129 Ibid., pp.588-598. BBKS, Senshi Sōsho: Marei Shinkō Sakusen, pp.39-40; BBKS, Senshi 262 There were two plans for landing army troops on the Malay Peninsula. The first plan was that main forces would make a landing at the same time as the air forces started their operations. This plan was proposed by the army. Cruising radiuses of army planes were far shorter than those of the navy, so it was impossible for them to cover landings directly from airfields in French Indochina. The navy considered that this plan was too risky and too dangerous. The second plan was that the main force would make a landing after the air forces attacked the enemy’s airfields and advanced units would occupy them. This was proposed by the navy. In the end, the navy yielded to the strong assertion of the army and accepted the first plan because the navy regarded operations in Malaya as the army operations. But the navy disagreed with simultaneous landings in Kota Bharu and southern Thailand. Consequently, whether to land in Kota Bharu at the same time as in southern Thailand remained to be decided.130 On arriving in Saigon, Tsuji started his work: preparation for the forthcoming operations. He decided to construct an airfield on Phuoquok Island at his own discretion. A staff officer, Asaeda, returned from his reconnaissance in southern Thailand reporting: (1) Disembarkation on the coast in the neighbourhoods of Singora and Patani will be under strong influence of the northeast monsoon about the Sōsho: Daihon’ei Rikugun-bu, 2. , pp.598-607; Kiyoshi Ikeda, “Japanese Strategy and the Pacific War, 1941-5” in Ian Nish (ed.) Anglo-Japanese Alienation 1919-1952: Papers of the Anglo-Japanese Conference on the History of the Second World War (Cambridge: Cambridge University Press, 1982), 130; Hatano, “The Anglo-Japanese War and Japan’s Plan to ‘Liberate’ Asia, 1941-1945”, p.202. 130 BBKS, Senshi Sōsho: Marei Shinkō Sakusen, pp.40-41. 263 middle of November. Seas approximately three metres high break against the shore. Because of the danger the local fishing craft not put to sea, and if we decide to use these beaches we must make up our minds to accept some sacrifice as inevitable. (2) There are scarcely any Thai troops defending the coast and the authorities not appear to be anxious. Fixed defences consist of a skirmishing line only, without wire entanglements, and there are no pillboxes in the neighbourhood of our proposed disembarkation points. (3) The Singora and Patani airfields are poor, crude and in no way comparable with the enemy’s airfields at Kota Bharu and in Kedah Province. It will therefore be of the utmost importance to seize the enemy’s airfields as soon as possible. (4) The road from Patani which passes through Betong to the upper Perak River valley is not good and can be used by motor transport only with difficulty. It will, however, be suitable for conduct of operations by a detachment of all arms of the service with one infantry regiment as nucleus.131 On 20 and 22 October, Tsuji conducted aerial reconnaissance. He was impressed by British airfields in northern British Malaya: “Comparing these well-developed airfields with the miserable airstrip at Singora was like comparing adults to children. Obviously our enemies would be able to deploy all their available air strength on these airfields. Even if, after disembarkation, 131 Tsuji, Japan’s Greatest Victory and Britain’s Worst Defeat, p.24. 264 we were to stop in the neighbourhood of Singora for a month, waiting for the rear troops to arrive, the idea of our air forces having to operate from the Singora airstrip against enemy forces based on this group of large airfields seemed to hold out little chance of success. There was therefore no other way for us to win except by rushing in immediately to attack Kedah Province by any means whatsoever as soon as we made a landing, in order to seize the enemy’s airfields. At any sacrifice, we had, first of all, to capture the enemy’s airfields at Kota Bharu and Alor Star, for use by our own air forces.”132 Based on Tsuji’s judgement, the 25th Army strongly advocated the necessity of simultaneous landing in Kota Bharu.133 On 10 November, General Terauchi and Admiral Yamamoto Isoroku, the Commander-in-Chief of the Combined Fleet, agreed on a “Tokyo Agreement” based on “The Army and Navy’s Southern Strategy Agreement”, which co-ordinated operational plans in the south between the army and the navy “under friendly atmosphere, without any conflict”134. The 25th Army consisting of 5D, 18D and Imperial Guards Division would attack British Malaya and Singapore. The Southern Force of the navy commanded by Vice-Admiral, Ozawa Jizaburō, would support the army landing on the Malay Peninsula. However, there was no complete understanding between the two armed forces in the “Tokyo Agreement”. Yamashita and Ozawa had to agree with what their superiors and staff officers in Tokyo disagreed. What was good for them was that Ozawa did not 132 133 134 Ibid., p.40. BBKS, Senshi Sōsho: Marei Shinkō Sakusen, p.42. Ibid., p.78. 265 share a strong hatred towards the army, which not a small number of naval officers had. On 18 November, Yamashita and Ozawa agreed to the “Saigon Agreement”. Ozawa accepted Tsuji’s assertion that airstrips in southern Thailand were too small, so it was impossible to secure command of the air by using them. Ozawa agreed with Tsuji that it was necessary to capture airfields in northern British Malaya, otherwise, it would become difficult for Japan to secure command of the air. In addition, Ozawa had intelligence that the British fleet, including capital ships, was in Ceylon and would advance to Singapore. In order to protect the convoy of the army’s reinforcements, it was necessary to secure command of the sea as soon as possible. If the Japanese landed in Kota Bharu, the British Fleet would definitely attack Japanese forces. It was good to invite the British fleet out into the South China Sea and annihilate it. Ozawa concluded that it was reasonable to agree with the army.135 According to Tsuji, when Yamashita referred to the difficulty associated with simultaneous disembarkations at Singora, Patani and Kota Bahru, Ozawa said: “I shall everything possible if the army desires it so much. I will be responsible for protection of the convoy of ships and of the disembarkation at Kota Bharu”136. This was the moment the two Commanders overcame the rivalry between the two armed forces. BBKS, Senshi Sōsho: Marei Shinkō Sakusen, p.43. Tsuji, Japan’s Greatest Victory and Britain’s Worst Defeat, p.48. This sentence was a translation from original text in Masanobu Tsuji, Shingapōru: Unmei no Tenki (Singapore: The Turning Point of History) (Tokyo: Tōzai Nanbokusha, 1952), p.62. 135 136 266 Conclusion Since Germany dominated the European Continent in May and June 1940 by defeating the Low Countries and France, both the Imperial Japanese Army and the Imperial Japanese Navy advocated south-bound military advancement. But there was no consensus between them. The army advocated war against Britain and the Netherlands while the navy emphasised the inseparability of Britain and the United States. For the Imperial Japanese Army, the purpose of south-bound advancement was to cut down supply routes to the Chinese Nationalists and capture natural resources in Southeast Asia, which were required for settling the war in China. The army advocated that war against the United States should be avoided. It was reasonable for the army to limit the number of enemies as much as possible. The most important military base of Anglo-Dutch powers in Southeast Asia was the Singapore Naval Base. Consequently, it became the most important military target in the south. The army supposed that, without attacking Singapore, it could not capture natural resources in Southeast Asia. On the other hand, the Imperial Japanese Navy emphasised the inseparability of the United States and Britain, and did not regard Singapore as so important. For the navy, the only power which had the capability to confront it equally and bombard the Japanese Islands was the United States. The American Pacific Fleet had been stationed in Pearl Harbour since April 1940 and there were air bases in the Philippines. Compared with American threats, British and Dutch fleets in the Asia-Pacific region, which did not possessed a capital ship, were negligible. In addition, even though there was 267 the naval base in Singapore, it was too far to bombard Japan by aeroplanes. It was reasonable for the navy to focus its attention on the United States. For the navy, the army’s plans which did not regard the United States as a threat as seriously as the navy did were too risky to accept. Furthermore, the United States was strengthening its navy. To counter the United States Navy, the Imperial Japanese Navy also had to strengthen its armaments, otherwise it could not wage war against the United States. Unless it built up its armaments enough to engage in naval battles with the United States Navy, the navy wanted to avoid war as far as possible. However, it could not unequivocally express this. It was afraid that the army would say, “If the navy can’t fight, give us your matériel and budget”, because the navy required war matériel and a larger budget to strengthen its armaments. Preparations for war became a convenient justification for this. Consequently, it advocated the necessity of war preparations and stressed the inseparability of Britain and the United States. Viewed in this context, the navy’s belligerent stance towards the United States was a verbal show of strength without determination for war. For the Imperial Japanese Navy, preparations for war and policies for avoiding war were compatible. The outbreak of the German-Soviet War on 22 June 1941 altered the situation drastically. The army’s traditional Hokushin Ron, (North-bound policy) was quickly revived. Within the army, some advocated war against the Soviet Union, and others advocated advancing to both the north and the south － war against the Soviet Union and south-bound military advance into Southeast Asia－because a supposed war against the Soviet Union needed the natural resources areas of Southeast Asia to secure a continued supply of war 268 materiel. The army required war in the south in order to conduct war in the north. But the course of the German-Soviet War was unclear, so that the army mobilised its force and kept it in a state of preparedness against the Soviet Union. To counter the army’s north-bound advance, the navy advocated south-bound advance more strongly than before, otherwise it feared that the army would snatch its materiel and budget. In this situation, Japan decided to advance its forces to southern French Indochina. Japan advanced its forces to promote preparations for war against Anglo-American powers without a clear determination for war. The Japanese needed air bases in southern French Indochina to attack British Malaya and Singapore. However, when they advanced, they had not yet made decision for war against the Anglo-American powers. Facing Japanese south-bound advances, the United States imposed a de facto oil embargo. But most Japanese naval and army officers did not expect a strong American reprisal. Japanese officers were much too absorbed in discussions between themselves over where Japan should advance, without seriously considering an American reaction. Facing the American de facto oil embargo, most middle-echelon naval officers regarded this as a belligerent act. They came to realise that war against Anglo-American powers was inevitable. On the other hand, the Army General Staff concluded on August 1941 that it would be impossible to go to war against the Soviet Union by the end of 1941 and postponed the decision as to whether or not it would go to war until the following spring. It also considered that it was a great opportunity to conduct war in the south during the coming winter for the purpose of capturing natural resources needed for conducting war against the Soviet Union in the next spring. The Army Department of Imperial General Headquarters (the Army 269 General Staff) formally ordered preparations for war in the south on 18 September 1941. In this way, Japan drifted toward war against the Anglo-American powers without a clear determination for war and unified national policy. The Japanese government after many twists and turns finally decided to provoke war against the Anglo-American powers on 26 November. After June 1940, the Imperial Japanese Army, especially the Operations Section, promoted preparations for attacking British Malaya and Singapore. Even the army and the navy disagreed over their adversaries, the navy did not interfere in the army plans to attack British Malaya and Singapore until the autumn of 1941. The navy left it to the army and concentrated its attention on the United States. Consequently, the army could promote preparations to attack British Malaya and Singapore on its own initiative. It sent its officers to gather information and establish the Taiwan Army Intelligence Unit to study how to fit its forces for combat in a tropical zone. In September 1941, after the United States imposed a de facto oil embargo and the Army General Staff decided to postpone war against the Soviet Union, the Army General Staff drew up its war plans, including operational plans to attack British Malaya and Singapore, by refining the “Annual Army’s Operational Plan for 1941”. As war against the Anglo-American powers became imminent, the navy started interfering with the army’s operational plans to attack British Malaya and Singapore. The Navy General Staff and the Combined Fleet judged that simultaneous landings in southern Thailand and Kota Bharu were too dangerous because the Japanese would land in the face of enemy. On the other hand, the army considered simultaneous landings were necessary to 270 capture airfields in northern British Malaya. Several meetings held in Tokyo between the army and the navy could not overcome this disagreement. But finally, Yamashita and Ozawa overcame Japanese sectionalism between the two armed forces on 18 November 1941 in Saigon. Ozawa considered the army’s assertion of simultaneous landings was reasonable to secure command of the air. In this way, the personal initiative of two commanding officers overcame sheer rivalry between their two armed forces. The British “Singapore Strategy” was a naval strategy and the Singapore Naval Base was a naval base. Whether Britain could send a fleet to Singapore or not was of great concern for Australians and New Zealanders. But ironically, Japanese plans for attacking Singapore were designed as the army’s operational plans. In fact, the Imperial Japanese Navy did not regard Singapore as an important military target. The navy regarded the United States Navy as the only naval power which had the capability to confront it. In the end, Japan plunged into the war without a complete co-ordinated plan between the two armed forces. In other words, Japan had no grand strategy. However, the Imperial Japanese Army had a sound operational plan to attack British Malaya and Singapore from the land side. On December 1941, the Imperial Japanese Army landed in Singora, Patani, and Kota Bahru. Singapore fell into Japanese hands on 15 February 1942. 271 [...]... In the summer of 1940, the army considered it would attack Singapore in concert with German landings in Britain By the spring of 1 941, however, the army came to realise that it was not easy for the Germans to land and conquer Britain From the summer of 1940 to the spring of 1 941, Japanese south-bound military policies were greatly influenced by events in Europe The Road to the War In Germany on 27 December... survival of the nation and the acceleration of the build-up of its war potential.59 Wenneker also visited Kondo to urge the Imperial Japanese Navy to attack Singapore, but Kondo’s answer was the (Tokyo, 1962), pp. 271 - 272 ; Haruo Tohmatsu, The Imperial Army Turns South: the IJA’s Preparation for War against Britain, 1940-1 941 in Ian Gow, Yoichi Hirama and John Chapman (eds.), The History of Anglo -Japanese. .. perplexed by the situation They wanted to promote preparations for military advancement to the south, 68 Kimitsu Sensō Nisshi, Jō, p. 97 69 Ibid., pp. 97- 98 Ibid., p.105 70 231 including preparations for attacking Singapore, but it was too early to carry them out What they chose was to use the “Outline of Policy toward the South”, which was an agreement between the War Guidance Office of the Army General... minutes of 8 August 1940 and 15 August, and the Chief of Staff report on the defence of Singapore and the Far East dated 31 July 1940 Aware of the importance of these documents, the commanding officer of Atlantis, Captain Rogge, sent them to the German Naval attaché in Tokyo, Real-Admiral Paul Wenneker, by a seized Norwegian tanker Ole Jacab Wenneker received the documents on 5 December He sent the originals... navy’s interests, by which they could claim more war matériel and a larger budget However, should they implement them, it meant war They were not ready for war In the process of making the “Outline of Policy toward the South”, the War Guidance Office made a large compromise with the navy The reason why the War Guidance Office could do this was the diminishing of the likelihood of 54 55 Ibid., pp.85-86... Asada, From Mahan to Pearl Harbor, p.242 37 38 2 17 establish policy from the Operations Division From then onwards, the War Guidance Office had the authority to establish Army General Staff’s policy, working under the direct supervision of the Vice-Chief of the Army General Staff Colonel Arisue Yadoru was appointed Chief of the War Guidance Office.40 Major Imoto Kumao returned from China to the Operations... decision of the Operations Division and the South China Army without any order coming down the chain of command The navy, which disagreed with the use of force, was infuriated by this act.38 The United States responded quickly They saw it as a prelude to Japanese further advancement in Southeast Asia.39 On 27 September, it embargoed the export of scrap iron to Japan On the same day, Japan signed the Tripartite... originals to Berlin by courier, radioed a summary of their contents, and telegraphically asked for permission to hand over copies of them to the Japanese Copies of them were delivered to the Vice-Chief of the Navy General Staff, Vice-Admiral Kondō Nobutake, on 12 December 47 The British documents portrayed an extremely pessimistic evaluation of Far Eastern defence, in which the British Chiefs of Staff... opposition to the Tripartite Pact－its enactment was promoted by the Imperial Japanese Army and the Ministry of Foreign Affairs while the navy had opposed to it the navy gained precedence over the army in the materials mobilisation programme As a punishment for disorders the Operations Division of the Army General Staff War caused within the Japanese government by advancing the army units into northern French... November 1940 to February 1 941, it discussed its plan with related bureaux, divisions and sections of the Ministry of War and the Army General Staff, especially the Operations Division and its Operations Section On 6 February, it presented its proposed plan “Outline of Policy toward the South” to them The points were: (1) The purpose of policy towards the south is to establish self-support Japanese economic . 1 97 Chapter 4 The Road to Singapore 1940 -41 Since Britain was included in the hypothetical enemies list of the Teikoku Kokubō Hōshin of 1936, the Operations Sections of the General. always been the principal hypothetical enemy of the Imperial Japanese Army. The conclusion of the German -Japanese Anti-Comintern Pact in 1936 and the outbreak of the Sino -Japanese War in the following. assisting the Chinese Nationalists. This policy was endorsed by the Minister of Foreign Affairs, the Minister of War and the Minister of the Navy in late 1939. On the other hand, the outbreak of the