United Kingdom China Empire of Japan Unknown tanks destroyed or damaged[7] 1941 1942 Second Sino-Japanese War Taishō period Shōwa period Asia-Pacific Mediterranean and Middle East Other campaigns Coups The Japanese invasion of Burma was the opening phase of the Burma campaign in the South-East Asian theatre of World War II, which took place over four years from 1942 to 1945.

[19] 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.

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.

[21] 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.

In late 1940 Aung San, a Burmese student activist, made contact with Suzuki Keiji in Amoy and voyaged to Japan for talks.

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.

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.

"[24] 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 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.

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[26] The Baluchis (actually consisting of companies of Dogras, Punjabi Mussalmans, and Pathans) were mostly fresh recruits, trained in desert warfare, and lacking arms and ammunition.

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.

[32] 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.

[31] 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.

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.[33] 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)[34] and the 63rd Indian Infantry Brigade, landed in Rangoon.

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.

They also brought in large numbers of captured British trucks and other vehicles, which allowed them to move supplies rapidly using southern Burma's road network, and also use Motorised infantry columns, particularly against the Chinese forces.

Unopposed Japanese bomber fleets attacked almost every major town and city in the Allied-held part of Burma, causing widespread destruction and disorder.

The flow of refugees began soon after the bombing of Rangoon in late December 1941 and increased to a "mass exodus" in February 1942 as the Indian (and Anglo-Indian and Anglo-Burmese) population of Burma fled to India, fearing both the Japanese and hostile Burmese.

Middle-class Indians and mixed-race refugees could often afford to buy tickets on ships or even planes, while ordinary labourers and their families in many cases were forced to make their way on foot.

[37] The commander of Burma Corps, Lieutenant General William Slim, tried to mount a counter-offensive on the western part of the front, but his troops were repeatedly outflanked and forced to fight their way out of encirclement.

The Japanese tried to cut off Burma Corps by sending troops by boat up the Chindwin River to seize the riverside port of Monywa on the night of 1/2 May.

[38] The majority of the refugees at Myitkyina were forced to make their way to India via the unhealthy Hukawng Valley and the precipitous forested Patkai Range.

Many died on the way, and when they reached India, there were several instances in which civil authorities allowed white and Eurasian civilians to continue while preventing Indians from proceeding, effectively condemning many to death.

The Chinese 38th Division however, commanded by Sun Li-jen, fought its way westward across the Chindwin, arriving at Imphal on 24 May, substantially intact although with heavy casualties.

[52] The Japanese advance in Arakan ended just south of the Indian frontier, prompting the British military and civil authorities in and around Chittagong to implement a premature "scorched earth" policy which contributed to the Bengal Famine of 1943.

[56] After the failure to take India, the British launched Operation Capital in December 1944 that led to the Battle of Meiktila and Mandalay in 1945 and the end of the Burma campaign.