The Japanese invasion of Burma, referred to by the BIA in 1941 as the fourth Anglo-Burmese war or the war of Burmese Independence, was a series of battles fought in the British colony of Burma (present-day Myanmar) as part of the Pacific theatre of World War II. The initial invasion in 1942 resulted in the capture of Rangoon and the retreat of British, Indian, and Chinese forces. The invasion had the support of the Burma Independence Army (BIA), which fought in view of decolonisation. However, Japan installed a puppet state in Burma, which lost the support of the Burmese people.
After the invasion, from 1942 to 1945, the Allies and Japan engaged in a protracted struggle for control of the region, marked by fierce fighting in challenging terrain. The Burma campaign was strategically significant, as it was linked to the war in China and the supply routes to the Chinese Nationalists. The eventual Allied victory in 1945 played a crucial role in the overall defeat of Japan.
Background
British rule in Burma
Before the Second World War broke out, Burma was part of the British Empire, having been progressively occupied and annexed following three Anglo-Burmese wars in the 19th century. Initially governed as part of British India, Burma was formed into a separate colony under the Government of India Act 1935. Under British rule, there had been substantial economic development but the majority Bamar community was becoming increasingly restive. Among their concerns were the importation of Indian workers to provide a labour force for many of the new industries, and the erosion of traditional society in the countryside as land was used for plantations of export crops or became mortgaged to Indian moneylenders. Pressure for independence was growing. When Burma came under attack, the Bamar were unwilling to contribute to the defence of the British establishment, and many readily joined movements which aided the Japanese.
British defences
British plans for the defence of British Far Eastern possessions involved the construction of airfields linking Singapore and Malaya with India. These plans had not taken into account the fact that Britain was also at war with Germany, and when Japan entered the war, the forces needed to defend these possessions were not available. Burma had been regarded as a military "backwater", unlikely to be subjected to Japanese threat.
Lieutenant General Thomas Hutton, the commander of Burma Army with its headquarters in Rangoon, had only the 17th Indian Infantry Division and 1st Burma Division to defend the country, although help was expected from the Chinese Nationalist government under Chiang Kai-shek. During the war, the British Indian Army expanded more than twelve-fold from its peacetime strength of 200,000 but in late 1941 this expansion meant that most units were undertrained and ill-equipped. In most cases, such training and equipment as the Indian units in Burma received was for operations in the Western Desert campaign or the North West Frontier of India, rather than jungles. The battalions of the Burma Rifles which formed most of the 1st Burma Division were originally raised as internal security troops only, from among minority communities in Burma such as the Karens. They also had been rapidly expanded, with an influx of Bamar soldiers, and were short of equipment and consisted mainly of new recruits.
Japanese plans
Japan entered the war primarily to obtain raw materials, especially oil, from European (particularly Dutch) possessions in South East Asia which were weakly defended because of the war in Europe. Their plans involved an attack on Burma partly because of Burma's own natural resources (which included some oil from fields around Yenangyaung, but also minerals such as cobalt and large surpluses of rice), but also to protect the flank of their main attack against Malaya and Singapore and provide a buffer zone to protect the territories they intended to occupy.
An additional factor was the Burma Road completed in 1938, which linked Lashio, at the end of a railway from the port of Rangoon, with the Chinese province of Yunnan. This newly completed link was being used to move aid and munitions to the Chinese Nationalist forces of Chiang Kai-Shek which had been fighting the Japanese for several years. The Japanese naturally wished to cut this link.
The Southern Expeditionary Army Group under overall command of General Hisaichi Terauchi was responsible for all military operations in the South-East Asia. The Japanese Fifteenth Army, commanded by Lieutenant General Shojiro Iida, was initially assigned the mission of occupying northern Thailand, which had signed a treaty of friendship with Japan on 21 December 1941, and attacking the southern Burmese province of Tenasserim across the Tenasserim Hills. The army consisted of the highly regarded 33rd Division and the 55th Division, although both divisions were weakened for several weeks by detachments to other operations.
Burmese insurgents
As the threat of war grew, the Japanese sought links with potential allies in Burma. In late 1940 Aung San, a Burmese student activist, made contact with Suzuki Keiji in Amoy and voyaged to Japan for talks. He and several other volunteers (the Thirty Comrades) were later given intensive military training on Hainan Island. The Burma Independence Army (BIA) was officially founded in Bangkok, Thailand on 28 December 1941. It consisted initially of 227 Burmese and 74 Japanese personnel. When the army entered Burma it numbered 2,300 men. As the Japanese and the BIA entered Burma, the BIA gained support from the civilian population and were bolstered by many Bamar volunteers. By the time the Japanese forces reached Rangoon on 8 March, the BIA numbered 10,000–12,000, and eventually expanded to between 18,000 and 23,000.
Japanese capture of Rangoon
On 22 December 1941, the Japanese 55th Division based in Bangkok, led by Lieutenant-General Takeshi Koga, was ordered to cross the Burma frontier, and capture Moulmein. By 17 January, the division was in Mae Sot, preparing to advance on Kawkareik, and then onwards to Moulmein. On 22 January 1942, the British evacuated Mergui. According to Louis Allen, "By 23 January 1942, the three important airstrips in southern Tenasserim – Tavoy, Mergui, Victoria Point – were all in Japanese hands, and fighter cover could now be provided for every bombing raid on Rangoon."
Rangoon was initially defended relatively successfully against Japanese air raids, by small RAF detachments reinforced by a squadron of the American Volunteer Group, better known as the "Flying Tigers". The majority of the airfields were between Rangoon and the Axis advance and as the Japanese gained use of the airfields in Tenasserim, the amount of warning the Rangoon airfields could get of attack decreased, and they became more and more untenable.
On 22 January 1942, the main body of the Japanese 55th Division began the main attack westward from Rahaeng in Thailand across the Kawkareik Pass. The 16th Indian Infantry Brigade of the 17th Indian Division guarding this approach retreated hastily westward. The Japanese division advanced to Moulmein at the mouth of the Salween River which was garrisoned by the 2nd Burma Infantry Brigade. The position was almost impossible to defend, and had the River Salween, almost 1.5 miles (2.4 km) wide, behind it. The 2nd Burma Brigade was squeezed into a progressively tighter perimeter, and eventually retreated over the river by ferry on 31 January after abandoning a large amount of supplies and equipment. Part of the force was left behind in Moulmein and had to swim the river.
Battle of Pa-an
In the early hours of 12 February, 1942, a battle was fought between three companies of the 7th battalion of the 10th Baluch Regiment (17th Indian Division), and three battalions of the 215th Infantry Regiment of the 33rd Japanese Division, at the village of Kuzeik along the west bank of the Salween River. The small town of Pa-an lay on the east bank. The Japanese crossed the river from Pa-an under the cover of darkness, on the night of 11 February, and attacked at 45 minutes past midnight.
The Baluchs (actually consisting of companies of Dogras, Punjabi Mussalmans, and Pathans) were mostly fresh recruits, trained in desert warfare, and lacking arms and ammunition. Nonetheless, they put up a stiff resistance, holding their position for several hours and engaging in much hand-to-hand combat. However, the Japanese were able to ultimately overrun the British positions by the morning of February 12, as they outnumbered the Baluchis five to one, had more prior battle experience, and benefited from attacks on the British positions at Kuzeik by Japanese dive bombers in the preceding days and hours. Less than a third of the Baluchs survived the battle.
The remnants of the British units from this battle retreated northward to the Brigade command at Thaton. This battle is mostly referred to as the 'Battle of Pa-an', and sometimes as the 'Battle of Kuzeik-Pa-an'.
Sittang Bridge
The 17th Indian Division soon fell back further northward. They attempted to hold the Bilin River (14-19 February) and other fallback lines as they did so, but had too few troops to avoid being continually outflanked. The division eventually retreated toward the bridge over the Sittang River in general disorder. The retreat was delayed by incidents such as a vehicle breaking through the bridge deck, air attacks (including, allegedly, accidental attacks by the RAF and AVG), and Japanese harassment. The delays allowed Japanese parties to infiltrate to the bridge itself, and the poorly organised defence of the bridge was in danger of collapsing. Fearing that the bridge would fall intact to the Japanese who would use it to advance on Rangoon, the divisional commander, Major-General "Jackie" Smyth, VC, ordered it to be blown up on the morning of 23 February 1942, with most of the division stranded on the enemy-held side.
Many of the men of the 17th Division who were trapped on the Japanese-held side of the river made their way across to the west bank by swimming or on improvised rafts, but had to abandon almost all their equipment, including most of their small arms. This later led some to question the decision to blow the bridge, arguing that the river itself did not offer much of an obstacle to the Japanese, and that more harm than good was achieved, as it resulted in the stranding of two brigades and delayed the Japanese capture of Rangoon by ten days at most.
Fall of Rangoon
Though the Sittang River was in theory a strong defensive position, the disaster at the bridge left the Allied forces too weak to hold it. General Archibald Wavell, the commander-in-chief of the ABDA Command, nevertheless ordered Rangoon to be held. He was expecting substantial reinforcements from the Middle East, including an Australian infantry division. On 28 February, he formally relieved Hutton (although Hutton had officially already been superseded in command by General Harold Alexander), and on the following day he sacked Smyth, who was in any case very ill.
Although the Australian government refused to allow its troops to be committed to Burma, some British and Indian reinforcements, including the British 7th Armoured Brigade (equipped with new M3 Stuart tanks) and the 63rd Indian Infantry Brigade, landed in Rangoon. Alexander ordered counter-attacks against the Japanese at Pegu, 40 miles (64 km) northeast of Rangoon, but soon realised that there was no hope of defending Rangoon. On 7 March, the Burma Army evacuated Rangoon after implementing a scorched earth plan to deny the Japanese the use of its facilities. The port was destroyed and the oil terminal was blown up. As the Allies departed, the city was on fire.
The remnants of the Burma Army faced encirclement as they retreated north from the city, but broke through the Taukkyan Roadblock as the result of an error on the part of the local Japanese commander. Colonel Takanobu Sakuma, commanding the Japanese 214th Infantry Regiment, had been ordered to block the main road north from Rangoon to Prome while the main body of the 33rd Division circled round the city to attack from the west. The retreating British and Indian troops were thrown back when they attempted to break through Sakuma's road block. Alexander ordered another attack but found the Japanese had gone. Not realising that the British were evacuating Rangoon, Sakuma had withdrawn the road block, as ordered, once the 33rd Division reached its intended positions. Had he not done so, the Japanese might have captured General Alexander and much of the rest of the Burma Army.
The Japanese Fifteenth Army claimed 930 abandoned enemy corpses and 156 POWs while suffering 178 killed and 201 wounded in the battle of Rangoon.