Pacific War 3 – Preparations Before the Invasion of Malaya

Pacific War 3 – Preparations Before the Invasion of Malaya

Introduction – the Strategic Realities

Malaya had for long time been safe, but this had rapidly changed in the last decade. Japanese imperial ambitions had led them to sieze and annex Manchuria in 1931 – 1932. In 1934, Japane renounced the Washington agreements, and in 1937 invaded China. Meanwhile, tensions had been rising in Europe, with British being well aware that the policy of appeasement will only delay war, not prevent it – yet that was the time they desperately needed.

Singapore Naval Base was officially opened in February 1938., but it became clear that deploying a large fleet to it would be impossible. After the fall of France and Italian entrance to war, British had to suspend their plan to send a large fleet to Far East. Even so, decision was made to defend Singapore, which would be a British centre of gravity in the Far East. Japanese Army had been tied down in China, which meant that there would be time enough to deploy reinforcements. But the plans did not foresee direction of war in 1940. and 1941., with British suffering a defeat after defeat. As a result, no reinforcements were available when Japan attacked.

Japanese themselves exploited situation in Europe to full. After the fall of France, Japan was able to secure permission from the Vichy French government to occupy French Indochina. This greatly increased threat to Singapore, as now Japanese ground troops and air bases were in range of Singapore. At the same time, strong American reaction to Japanese expansionism meant that war was Japan’s only choice, as it could not give in to American demands.

When Germany attacked USSR in June 1941., Japan had a choice to attack either Russia or Great Britain. But several factors pushed towards the latter, most importantly the fact that Russian Far East did not have all the resources that Japan needed to support its economy. Thus, a decision was made to occupy Malaya and Dutch East Indies. Occupation of the French Indochina fulfilled a major strategic prerequisite, allowing Japan to directly threaten both Malaya and Singapore. But it also meant that Japan was locked on a war path: occupation of Indochina meant that United States, Britain and Netherlands all slapped embargo on Japan, and with no access to oil, Japan had to turn to conquest in order to secure oil supply.

Opposing Sides

The British Empire


Weakness of British air and naval forces, but also the strategic geography of the area after Japanese occupation of Indochina, meant that the primary responsibility for defence of Malaya and Singapore fell to the ground forces, organized in Percival’s Malaya Command. But this command was understrength, ramshackle affair. Percival believed he needed 48 infantry battalions and 2 armored regiments to accomplish his mission. He had no armor, and only 31 infantry battalion organized in two Indian and one Australian division. All three divisions were understrength – counting only two brigades each – and had little in terms of artillery. Two more brigades were in reserve, and two fortress brigades manned Singapore. There were also units of coastal and anti-aircraft artillery in Singapore, as well as local defense units. The total strength was approximately 88,600 personnel of which 19,600 were British, 15,200 Australian, 37,000 Indian and 16,800 local troops.

Indian troops

This was a ramshackle collection of units from all over the Empire. They had no combat experience, no time to train together, and no experience with conditions in Malaya or any training in jungle warfare. Most Indian units were manned by poorly trained recruits, and their combat value was essentially nonexistent. None of the units – Indian or otherwise – trained with tanks, or were trained in anti-tank warfare. British battalions had had no time to conduct field training, and most of their experienced personnel had been sent to replace losses in other theatres, leaving nobody available to help train new recruits. Command staffs and specialists were likewise short on manpower. Training itself was deficient on both individual and unit level, with no training for jungle and antitank warfare, or utilization of experience from other theatres. Thus it is no surprise that some units disintegrated as soon as they saw combat.


British defensive plan rested primarily on arrival of reinforcements. But while reinforcements did arrive, events elsewhere ensured that these were too little and too late to stem the Japanese tide. The primary reinforcement was the 18th Infantry Division, which was the only British division to fight in the campaign. It was well-trained and well-equipped, and the lead elements arrived to Singapore on 13 January 1942. The bulk of division arrived on 5 February, but sinking of one of the four transport ships carrying division’s equipment left its reconnaissance and anti-tank battalions without equipment. The division saw only a few days of combat, and went into captivity without having fought a single major action.

The 44th Indian Brigade was formed on 1 June 1941., but it had poor equipment and worse training. What little training did occur was based on the assumption that it would be deployed to the Western Desert. When it arrived to Singapore on 22 January 1942, it had it was still poorly trained, poorly equipped and with an insufficient number of officers.

The 45th Indian Infantry Brigade was also created on 1 June 1941, and had all the flaws of the 44th . Despite weak training and lack of officers, it was sent to combat immediately upon arrival to Singapore on 3 January 1942. Finding itself in the path of Imperial Guards Division on 10 January, it got reduced to 1 000 men in just three days of fighting. Losing its commanding officer on 20 January, it was routed over the next three days, disbanding on 1 February 1942.


Standard British ground combat unit was an infantry battalion. It consisted of four infantry companies, a headquarters company with mortar, machine gun and anti-tank platoons for a total strength of over 800 men. They were also well provided with heavy weapons, with some 40 Bren light machine guns and six 3-inch mortars. Three battalions made up a brigade, for a total of 2 500 men. These brigades were then formed into brigade groups, and provided with additional divisional artillery, anti-tank and anti-aircraft elements. British and Australian brigades were nationally homogenous, while Indian brigades had two Indian and one British battalion, with British officers. No tanks were available for defense of Malaya, with only some improvised armored personnel carriers and armored cars being available, none of which could counter Japanese tanks. British units did have good artillery support, including anti-tank guns (at numbers of 48 2-pounders in four batteries per division), but this made them very immobile.


The Chiefs of Staffs in London estimated that a successful defence of Malaya would require 336 modern aircraft in 22 squadrons. They were wildly off the mark – service commanders in Malaya instead recommended in October 1940 that a force of 566 aircraft in 31 squadron would be required, so as to counter a simultaneous attack from land through Thailand and from sea further south. What they had was, despite the best efforts, far from this. During 1941., Malayan command was increased from four squadrons to twelve, with another being organized. When war broke out there were 14 squadrons with 215 aircraft.

This was nowhere nearly enough. Worse, instead of high-performance modern aircraft, majority of these aircraft were either outdated or else had aircraft types significantly inferior to first-line combatants. The four fighter squadrons had only arrived in 1941., and were equipped with a very slow and very sluggish US-built Buffalo fighters, unsuited for any serious combat. Other squadrons – one night fighter, two light bomber and two reconnaissance – were much better off in terms of aircraft, but simply did not have numbers. Lastly, there were two torpedo bomber squadrons equipped with antiquated Vildebeest torpedo bombers. Their crews were not much better off, with majority of aircrews lacking fully trained, much less experienced, cadre. Airfields themselves were poorly protected. What radar units were available – six early warning radars in total – were concentrated in Singapore, leaving air fields with no early warning system. Ground-based defences of air fields were likewise lacking.

British Brewster Buffalo
Brewster Buffalo


Naval power was a key to defense of Singapore, and the primary task of both ground and air forces in Malaya was, in fact, a defense of naval base at Singapore. Yet the requirements of war in Europe meant that the Royal Navy was unable to station significant forces there in a period leading up to war. Only permanent naval presence there were three World War I era light cruisers. A modern light cruiser and five destroyers were also at the naval base undergoing repair or refit, and there were some shore gunboats available. Only the arrival of Force Z gave the British a naval force capable of disrupting the Japanese naval communications, but this force was soon destroyed as detailed in a previous article, and thus Royal Navy ceased to play a role in the campaign.

The Japanese Empire


The IJA force fielded for the Malayan campaign was likely the best led, best organized, best supported and best equipped force of the entire Pacific War. While outnumbered by the British forces, Japanese Army invasion force actually had significantly greater combat strength. It had extensive armour, artillery and engineering support, and had also trained for jungle operations. High degree of confidence, ability to operate with minimal logistical support, high degree of confidence and highly developed infantry tactics allowed it a high chance of success.

Japanese tactics compensated for IJA’s lack of firepower through usage of surprise and concealment. Landings were carried out in darkness whenever possible, and enemy shore defences were outflanked instead of being smashed into pieces as per Allied practice. Once ashore, forces pressed inland as quickly as possible instead of consolidating the landings. British had planned to preempt this via Operation Matador, by siezing landing sites in southern Thailand, but this was not carried out.

Once ashore, IJA emphasized speed and power of the attack – similar to German maneuver warfare, at least in its basics. Preferred tactics were single and double envelopment, as well as the penetration into enemy rear area. This served them well against the road-bound British forces in Malaya, which were highly vulnerable to Japanese tactics as a result of their limited mobility. When frontal attack was necessary, infiltration would locate weak spots that the main attack could exploit. Goal was to penetrate to the rear and attack command facilities, artillery and reserves. In order to maintain surprise, artillery preparation was minimal and so the attack was supported by battalion and regimental weapons. The problem was that Japanese preferred hasty attacks even against larger enemy forces in prepared defensive positions. While successful against poorly trained and ill-prepared troops early in the war, they would prove futile later in the war.


While usually infantry-heavy, for Malayan campaign IJA gave the 25th Army extensive motorization, including 1 520 trucks, 160 light and medium tanks, as well as a number of independent artillery and engineering units. Latter would prove crucial for maintaining pace of the advance.

IJA weapons were of a mixed quality. Quality of infantry weapons and field artillery pieces was comparable to the British. The infantry squad was built around the 6.5mm Type 96 light machine gun, which was supported at the battalion level by the 7.7mm Type 92 machine gun. Every IJA company had nine 5 cm Type 89 heavy grenade dischargers. Main fire support was provided by the Type 92 70mm battalion gun.

Japanese Army Type 92 battalion gun
Type 92 battalion gun

The field artillery regiment of an IJA infantry division had 2 100 men and 36 guns. The 18th Division was equipped with 36 75mm mountain guns. The 5th Division was equipped with two battalions of 24 75 mm field guns and a single 12-gun battalion of 100 mm weapons. This was also the organization of the Imperial Guards Division artillery regiment.

Tanks were seen and utilized primarily as infantry support weapons, though Malayan campaign saw some very successful cases of tank usage. The 25th Army received a large tank contignent, as the Japanese had correctly assessed that tanks would be useful in Malaya. Three tank regiments assigned to the 3rd Tank Group had a total of 85 light and 74 medium tanks. Type 97, IJA’s medium tank, had a low-velocity 57mm gun and two machine guns, 28 mm of frontal hull armour and 50 mm on the gun mantlet. This made it vulnerable to British 2 pdr anti-tank gun, but weight of 15 tons meant that it could in fact cross bridges available in Malaya. The Type 95 light tank weighted 10 tons, carried 3,7 cm gun and two machine guns. For comparison, German Panzer III had a 50 mm cannon, later upgraded to low-velocity 75 mm gun, 70 mm maximum armor and a weight of 15 tons. Panzer II had a 20 mm gun, one machine gun, and armour no more than 14,5 mm thick, and weighted 7,9 tons. In addition, there was a small number of tankettes, armed with machine guns only and only suitable for reconnaissance.

Japanese Type 97 tank
Type 97

The 25th Army had four divisions assigned for conquest of Malaya and Singapore, out of 11 divisions dedicated to operations in southern areas. Yamashita however left the 56th division in Japan for logistical reasons. Main force for the initial phase of the campaign was 5th division, which was also one of the oldest units in IJA. It had square organization, with two infantry brigade group headquarters, each having two regiments, which gave it flexibility. It also had a division reconnaissance units with a small number of tankettes. Division was motorized and trained for amphibious operations, making it ideal for the Malaya campaign, and also had combat experience in China.

The 18th division also had extensive combat experience and was also a square division, but one infantry regiment had been detached for the invasion of Northern Borneo. This left it with three infantry regiments, an artillery regiment with 36 75 mm mountain guns and a reconnaissance unit with small amounts of armor.

Last unit was the Guards Division. This division had an infantry and artillery group headquarters which controlled the three infantry regiments (3rd, 4th and 5th Guards) and the 2nd Guards Field Artillery Regiment with 24 75mm field guns and a battalion of 12 105mm howitzers. There was also an organic reconnaissance regiment with 600 men. The division was trained for ceremonial duties and had no real combat experience, but still performed adequately in the Malayan campaign.


The attack on Singapore was supported by IJA’s 3rd Air Division. Division consisted of three air brigades, with each having two to four air regiments. Fighter regiments had 48 fighters organized into three squadrons of 16 aircraft. These included Ki-27 Nate, a highly maneuverable fighter with fixed landing gear, and Ki-43 Oscar, also highly maneuverable but with only two 12,7 mm machine guns. Still, Oscar was superior to Buffalo and comparable to the Hurricane, which arrived later in the campaign.

Nakajima Ki-43 Oscar
Nakajima Ki-43 Oscar

Bomber regiments consisted of 27 aircraft divided into three squadrons of nine aircraft. These were equipped with Ki-48 “Lily” light bomber and Ki-21 “Sally” heavy bomber. Latter was able to strike Singapore from its bases in southern Indo-China while carrying 1 000 kilograms of bombs. While Japanese Air Force did not perform true close air support, it did carry out battlefield interdiction missions, with strikes against British headquarters, artillery positions and along roads.


Imperial Japanese Navy was a key to conducting operations over vast areas of the Pacific Ocean. Since southern thrust was high priority, it was assigned a large portion of IJN’s most powerful units. Since carrier force was required for attack on Pearl Harbor, air support was provided by land-based aircraft based in Southern Indo-China. From there, these aircraft could hit Singapore and cover the South China Sea. Aircraft were drawn from the 21st and 22nd Air Flotillas and totalled 99 bombers. These were the long-range G3M “Nell” and G4M “Betty” bombers, which were capable of level bombing of land and naval targets and conducting torpedo attacks against naval units. Units deployed were specifically trained to attack warships, which will later be displayed during attacks against Prince of Wales and Repulse. Also present were 25 A6M Mitsubishi “Zero” fighters, far superior to anything British had in Malaya.

Mitsubishi A6M3 Zero
A6M3 Zero

Surface force for the southern offensive was built around a powerful force of heavy cruisers. Battleships remained in the home waters for anticipated decisive battle against the US Navy, but four fast battleships of the Kongo class were assigned to the southern operation. Still, these were inferior to Prince of Wales, and so IJN preferred to engage in any surface action at night. In such conditions, a large force of heavy cruisers and destroyers equipped with Long Lance torpedoes would have given the Japanese fleet a decisive advantage. Seven heavy cruisers assigned to the southern operation were probably the most powerful in the world, though as with other Japanese warships they tended to be top-heavy and thus unstable and vulnerable to flooding damage. Some Japanese destroyers had as many as nine torpedo tubes with reloads.

Opposing Plans

Both the British and the Japanese were aware that Singapore and Malaya were strategically inseparable – if one was lost, the other could not be held. And both recognized the only viable way of capturing Singapore was an advance down the length of Malaya, and that air power was potentially decisive.

Japanese invasion of Malaya

While Malayan peninsula is large – 400 miles long and 60 to 200 miles wide – operations themselves were restricted to the coastal areas, as center of the peninsula is taken up by a mountain range. But the coastal areas were also a very problematic terrain. North-south movement was impeded by many rivers flowing toward the sea from the central mountain range. Mangrove swamps formed around the estuaries, but the most significant terrain was dense jungle. The east coast was completely covered in jungle, with only a few roads, while on the west coast the jungle had been partly cleared for cultivation and road network was more extensive. Humid conditions meant that new troops needed a period of acclimation, and monsoons would hamper the movement during the season.

British Defense Plans

Britain was in difficulty on every front, and so very few forces could be spared to the Far East. Britain had sent large numbers of tanks and aircraft to the Soviet Union after German invasion of USSR, which meant even less was available for Malaya. Churchill also believed that Japan would not attack in the Far East since it would mean going to war with the United States. He also believed that so long as the fortress of Singapore was held, this would be sufficient. Both assumptions were wrong, which was admittedly usual for Churchill whenever he went out of the area of politics.

The British Chiefs of Staffs concurred with the pre-war assessment that the only way to hold Singapore is to hold Malaya. This will have required large ground, air and naval forces to be allocated to the Far East, but these were simply not available in 1941. What forces were available amounted to third-line units as well as Prince of Wales and Repulse. Thus the entire defence scheme was a house of cards, and led to loss of two capital ships, both of which would have been better utilized in Indian Ocean or Australia later on.

Beyond complete inability to comprehend reality, British defense planning also had problem with inability to coordinate various services. RAF had built its air bases along the eastern coast to extend range of bombers against Japanese ships, but these bases could not be properly defended – available Army and Navy forces might have protected Singapore itself, but little more. Percival’s 1937 – 38 plan assumed defense of Singapore on a line some 30 miles north of the naval base. This was in fact the only realistic way of defending Singapore. But RAF displayed its traditional disregard for reality and instead demanded that its air bases strewn all across Malaya be defended at any cost. RAF got its way, and the plan for concentrated defense of Singapore was abandoned. In May 1941., Indian III Corps was established and and given the mission to defend Northern and Central Malaya. The defence of Johore was given to 8th Australian Infantry Division. Two brigades were assigned to the Singapore Fortress. A single Indian brigade was held in reserve.


In order to preempt Japanese invasion or at least push it back before it could establish a foothold, the Commander-in-Chief Far East proposed a plan to move into southern Thailand to establish defensive positions at Singora and Patani before the Japanese could land. This plan, codenamed Operation Matador, offered a real possibility of disrupting Japanese operations as Singora was the only major port in the area, and denying it would have forced the Japanese to advance south from Bangkok or conduct a risky amphibious attack at Kota Bharu. But since it violated the territory of a neutral country, London forbade the plan for fear of turning public opinion in United States against the UK. Plan may have still succeeded had local commander been given authority to move as soon as the Japanese force was spotted at sea, but that was not done either. As a result, plan was essentially dead – yet the fact that 11th Indian Infantry Division had been charged with carrying it out meant that it was not able to finish defensive positions at Jitra, which had immediate consequences on the campaign.

This and RAF’s demands forced Percival to spread his forces out. 11th Indian Infantry Division, consisting of only two brigades, was positioned to intercept invasion from Thailand. 9th Indian Infantry Division, which likewise had no reserve brigade, was deployed on the east coast to defend airfields at Kota Bharu and Kuantan. Mutual support between brigades, let alone divisions, was impossible, and Percival had earlier rejected a proposal from his chief engineer, Brig. Ivan Simson, to build a countrywide system of defences.

Overall, British actually should have had good possibility of successful defense, but any chances of victory were ruined by RAF and Percival himself. RAF spread out air bases all across the country to defend nothing in particular, and then demanded these air bases be defended. This stretched the Army all across the peninsula, and opened them up for a defeat in detail. In fact, British would likely have had a bette chance of success if Percival had told RAF to stick their demands where the sun doesn’t shine. Percival himself had neglected construction of any defences, and also allowed himself to be surprised by the timing as well as the execution of Japanese campaign. The entire plan was also flawed from the outset: idea was to defend the naval base in Singapore, but it is hard to see any benefit of the base that could not be gained by basing ships in Ceylon or Australia.

The Japanese Plan

Attack into Malaya was only one part of a much larger Japanese offensive. The most important part of the plan was destruction of the US fleet at Pearl Harbor, but second important objective was capture of Singapore before it could be properly reinforced. Once that was accomplished, the entire Allied defence of Southeast Asia would be fatally compromised.

While the Navy provided surface escort, most of the air power for Malaya was provided by the Imperial Japanese Army. Ground troops themselves were limited as only 11 divisions could be allocated to the Philippines, Malaya and the Dutch East Indies. As a result, the Japanese were actually outnumbered on the ground.

Japanese started work on jungle warfare doctrine in December 1940. On 25th August the Imperial Japanese Army started preparing a plan for the attack on Malaya. As usual, the plan depended on the enemy being a bunch of idiots who followed Japanese plan to a letter. Luckily, this assumption proved true. The plan called for multiple landings along the coast of Malaya followed by an advance towards Singapore along the western coastal plain. Landings in Thailand were chosen because the Japanese knew that the Thais would not put up a defense and that the British will not advance into Thailand. Quick seizure of ports would allow the Japanese to quickly establish disembarkation and supply points, and seizure of airfields would allow the 3rd Air Division to establish bases. Once ashore, army units would advance to capture the air fields at Perak river. After 23rd December, the advance on Kuala Lumpur would commence. Landing at Kota Bharu, assigned to the 56th Infantry Regiment of the 18th Division, was intended to protect the main landing from attack by siezing three nearby airfields.

Japanese landing at Kota Bharu
Landing at Kota Bharu

Yamashita had been convinced that it was better to risk supply problems than to pause after landing to build up his forces. Thus, the 5th Division would advance to the left bank of of the Perak River as quickly as possible to create conditions for the continued advance into Malaya. The Imperial Guards division would then carry out an amphibious landing on the east coast of Malaya. This driving strategy would allow the Japanese to destroy the British forces before they could withdraw to Singapore – showing yet again how truly destructive for the British was RAF’s insistence on defense of the airfields. To maintain the speed of the advance, infantry would move along the roads until contact was made. Then, the Japanese would move through the adjoining jungle or plantations to encircle the enemy. Once the enemy was flanked, the Japanese forces would set up roadblocks to complete the encirclement.

Overall, Japanese plan was audacious to the point of recklessness, but much as with German plan for invasion of France, it was the only way for them to win: leveraging mobility and firepower against an opponent who significantly outnumbered them and had time to prepare defensive positions. The driving strategy was a complete success, keeping the British off balance and the initiative in Japanese hands.

Initial Landings

Japanese troop convoys departed on 4th and 5th of December, taking route near the coast to avoid detection. Since 3rd of December, the British had been flying search missions over the South China Sea, but not in the Gulf of Thailand. Still, Japanese convoys were noticed on 7th December at 17:30, headed toward Singora and Patani. But as this information was insufficient to confirm that the Japanese were intent on invading southern Thailand, no action was taken. But as Japanese landing started at Kota Bharu on 8th December at 00:45, the Hudsons stationed at Kota Bharu conducted moonlight attacks, sinking one and damaging two ships.

Landing at Kota Bharu was difficult due to heavy swell and prepared defences of an Indian battalion. But by 3:45 they had penetrated the line, and after an unsuccessful counterattack by two Malayan battalions, order was given to destroy the airfield. As additional Japanese troops arrived, the British forces retreated and Japanese occupied Kota Bharu. Next morning, Japanese began to infiltrate around British strongpoints, and on the 10th British surrendered the airfields at Gong Kedah and Machang. This meant that the Japanese now had a secure route of airborne resupply.

Learning of these landings, Admiral Tom Phillips decided to take battleship Prince of Wales, battlecruiser Repulse and a force of four destroyers to intercept the Japanese landing force. He was aware that naval interception was the only hope of actually stopping the Japanese invasion, but as usual, what he didn’t know was what killed him.

Continues in the Loss of Prince of Wales and Repulse

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