Malayan campaign
The Malayan campaign, referred to by Japanese sources as the Malay Operation, was a military campaign fought by Allied and Axis forces in Malaya from 8 December 1941 – 15 February 1942 at the opening of the Pacific War and during the Second World War. It was dominated by land battles between British Commonwealth army units and the Imperial Japanese Army, with minor skirmishes at the beginning of the campaign between British Commonwealth and Royal Thai Police. The Japanese had air and naval supremacy from the opening days of the campaign. For the British, Indian, Australian, and Malayan forces defending the colony, the campaign was a total disaster.
The operation is notable for the Japanese use of bicycle infantry, which supposedly allowed troops to carry more equipment and swiftly move through thick jungle terrain. Royal Engineers, equipped with demolition charges, destroyed over a hundred bridges during the retreat, yet this did little to delay the Japanese. Japanese air supremacy, infiltration tactics, superior leadership, and experienced infantry units ensured an overwhelming victory over the unorganized Allied forces.
By the time the Japanese 25th Army had captured Singapore, they had suffered between 9,657 and 14,768 casualties. Allied losses were much heavier at 130,246 to 138,708, including around 7,500 to 8,000 killed, 10,000 to 11,000+ wounded and 120,000+ missing or captured. Between 20,000 and 83,000 civilians were killed in the campaign, mostly victims of the Sook Ching Massacre.
Background
Japanese
By 1941 the Japanese had been engaged for four years in trying to subjugate China. They were heavily reliant on imported materials for their military forces, particularly oil from the United States. From 1940 to 1941, following the Japanese takeover of French colonies the United States, the United Kingdom, and the Netherlands imposed embargoes on supplying oil and war materials to Japan. The object of the embargoes was to assist the Chinese and encourage the Japanese to halt military action in China. The Japanese considered that pulling out of China would result in a loss of face and decided instead to take military action against US, British and Dutch territories in South East Asia. The Japanese forces for the invasion were assembled in 1941 on Hainan Island and in French Indochina. This troop build-up was noticed by the Allies and, when asked, the Japanese advised that it related to its operations in China.When the Japanese invaded, they had over 200 tanks, consisting of the Type 95 Ha-Go light tank, Type 97 Chi-Ha and Type 89 I-Go medium tanks and Type 97 Te-Ke tankettes. In support they had nearly 800 aircraft available. Commonwealth troops were equipped with the Lanchester 6x4 Armoured Car, Marmon-Herrington Armoured Car, Universal Carrier and only 23 obsolete Mk VIB light tanks, none of which were sufficiently armed for armoured warfare. They had just over 250 combat aircraft; half of these would be lost in the first few days of combat.
When the Japanese invaded Malaya it was part of expansive attack all across the Pacific and South East Asia, stretching from Pearl Harbor and islands in the Pacific, the Philippines, Hong Kong, Burma, Singapore, Borneo, and Thailand.
Commonwealth
Between the wars, the British military strategy in the Far East was undermined by a lack of attention and funding. In 1937, Major-General William Dobbie, General Officer Commanding Malaya, looked at Malaya's defences and reported that during the monsoon season, from October to March, landings could be made by an enemy on the east coast and bases could be established in Siam. He predicted that landings could be made at Songkhla and Pattani in Siam, and Kota Bharu in Malaya. He recommended large reinforcements to be sent immediately. His predictions turned out to be correct, but his recommendations were ignored. The British government's plans relied primarily on the stationing of a strong fleet at the Singapore Naval Base in the event of any enemy hostility, in order to defend both Britain's Far Eastern possessions and the route to Australia. A strong naval presence was also thought to act as a deterrent against possible aggressors.By 1940, however, the army commander in Malaya, Lieutenant-General Lionel Bond, conceded that a successful defence of Singapore demanded the defence of the whole peninsula, and that the naval base alone would not be sufficient to deter a Japanese invasion.Bayly/Harper, p. 107 Military planners concluded that the desired Malayan air force strength would be 300–500 aircraft, but this was never reached because of the higher priorities in the allocation of men and material for Britain and the Middle East.
The defence strategy for Malaya rested on two basic assumptions: first, that there would be sufficient early warning of an attack to allow for reinforcement of British troops, and second, that American help was at hand in case of attack. By late 1941, after Lieutenant-General Arthur E. Percival had taken over as GOC Malaya, it became clear that neither of these assumptions had any real substance. In addition, Churchill and Roosevelt had agreed that in the event of war breaking out in South East Asia, priority would be given to finishing the war in Europe. The east, until that time, would be a secondary priority. Containment was considered the primary strategy in the east.
Intelligence operations
Planning for this offensive was undertaken by the Japanese Military Affairs Bureau's Unit 82 based in Taiwan. Intelligence on Malaya was gathered through a network of agents which included Japanese embassy staff; disaffected Malayans ; and Japanese, Korean, and Taiwanese business people and tourists. Japanese spies, which included a British intelligence officer, Captain Patrick Stanley Vaughan Heenan, also provided intelligence and assistance.Prior to hostilities Japanese intelligence officers like Iwaichi Fujiwara had established covert intelligence offices that linked up with the Malay and Indian pro-independence organisations such as Kesatuan Melayu Muda and the Indian Independence League. The Japanese gave these movements financial support in return for their members providing intelligence and later assistance in determining Allied troop movements, strengths, and dispositions prior to the invasion.
Through the operation of these networks prior to the invasion the Japanese knew where the Commonwealth forces were based and their unit strengths, had good maps of Malaya, and had local guides available to provide them with directions.
November 1941
In November 1941, the British became aware of the large scale buildup of Japanese troops in French Indo-China. Thailand was seen to be under threat from this build-up as well as Malaya. British strategists had foreseen the possibility of Thailand's Kra isthmus being used by the Japanese to invade Malaya. To counteract this potential threat, plans for a pre-emptive invasion of southern Thailand, named Operation Matador, had been drawn up. By the time the invasion became highly likely the British decided not to use them for political reasons.Japanese invasion of Malaya
The Malayan campaign began when the 25th Army, under the command of Lieutenant General Tomoyuki Yamashita, invaded Malaya on 8 December 1941. Japanese troops launched an amphibious assault on the northern coast of Malaya at Kota Bharu and started advancing down the eastern coast of Malaya. The Japanese 5th Division also landed at Pattani and Songkhla in Thailand, then moved south into western Malaya. French Indo-China was still under French administration, and had little option but to co-operate with the Japanese. The French authorities therefore submitted to the Japanese military using the territory's ports as naval bases, building air bases, and massing forces there for the invasion. Japan also coerced Thailand into co-operating with the invasion, though Thai troops resisted the landings in Thai territory for eight hours.At 04:00, 17 Japanese bombers attacked Singapore, the first ever air raid on the colony. It became evident to the British that Japanese bombers based in Indochina were now within range of Singapore.
The Japanese were initially resisted by III Corps of the Indian Army and several British Army battalions. The Japanese quickly isolated individual Indian units defending the coastline, before concentrating their forces to surround the defenders and force their surrender. The Japanese forces held a slight advantage in numbers in northern Malaya and were significantly superior in close air support, armour, co-ordination, tactics, and experience, having fought in the Second Sino-Japanese War. The Allies had no tanks, which had put them at a severe disadvantage. The Japanese also used bicycle infantry and light tanks, which allowed swift movement of their forces overland through terrain covered with thick tropical rainforest, criss-crossed by native paths. Although the Japanese had not brought bicycles with them, they knew from their intelligence that suitable machines were plentiful in Malaya and quickly confiscated what they needed from civilians and retailers.
A replacement for Operation Matador, named Operation Krohcol by the British Indian Army, was implemented on 8 December, but the troops were easily defeated by the Royal Thai Police and the Japanese 5th Division. Force Z of the Royal Navy had arrived right before the outbreak of hostilities. Japanese aircraft based in Indochina sank Prince of Wales and Repulse on 10 December, leaving the east coast of Malaya exposed, allowing the Japanese to continue their invasion.
Air war
Background
As a lower-priority theatre, the Allies had comparatively few modern aircraft to challenge the Japanese. In addition the Allies did not consider Japanese aircraft a significant threat. In 1941 the Allies assumed that Japan would only have a few hundred poor quality outdated aircraft. The respected Janes All the World's Aircraft for 1941 indicated that the Japanese only had a cluster of dated foreign and indigenous aircraft. Japanese pilots were also underrated, considered unlikely to make particularly good pilots.Prior to the invasion on 8 December there were 75 Allied aircraft stationed in northern Malaya and 83 in Singapore. The only fighter squadron in northern Malaya was No 21 Squadron RAAF that was equipped with 12 Brewster Buffalos. The Japanese had at least 459 aircraft available.