The end of the Japanese invasion of India

Under 22 August 1944, war chronologies record that the Japanese were “in full retreat from India”. The day was not the date of any battle or order; rather, it marks the point at which it became clear that the Japanese invasion of India was over for good. The offensive against Imphal and Kohima, launched in March under the codename U-Go, had already been called off on 3 July. In the second half of July and in August the remnants of the Japanese Fifteenth Army, worn down by hunger and disease, were falling back in the monsoon rains from the Indian state of Manipur across the mountainous borderlands towards the Chindwin river in Burma. On 12 August Imperial General Headquarters in Tokyo admitted in a communiqué that the units fighting “around Kohima and the Imphal plain” had in early August “straightened their front near the Indo-Burmese border” – a euphemism that concealed the defeat from the Japanese public.

By the end of August no coherent Japanese forces remained on Indian soil; only on the Tiddim road, south of Imphal, were rearguards of the 33rd Division delaying the pursuit in the border mountains. So ended the only major Axis land offensive of the war into mainland British India – an undertaking that the propaganda of Subhas Chandra Bose presented as the start of the “march on Delhi”, and which ended in the Japanese army’s greatest defeat on land up to that time.

An operation called off

Lieutenant General Renya Mutaguchi, commander of the Fifteenth Army, went on ordering fresh attacks on Imphal until the end of June, even though his divisions were in no state to carry them out. After the end of the siege of Imphal on 22 June the road from Kohima to Imphal was open again, and the Japanese units north and south of the plain were wasting away from hunger, malaria, dysentery and beriberi. According to Japanese studies, the commander of the Burma Area Army, Lieutenant General Masakazu Kawabe, on receiving Mutaguchi’s request to call off the operation, endorsed it to the commander of the Southern Expeditionary Army Group, Field Marshal Hisaichi Terauchi, and Tokyo – preoccupied at the same time with the fighting on Saipan – agreed. On 1 July Hideki Tōjō, Prime Minister and at the same time Chief of the Army General Staff, presented the decision to halt the offensive to the Emperor, and on 3 July the order reached the Burma Area Army: the Fifteenth Army was henceforth to stand on the defensive west of the Chindwin.

Mutaguchi still tried to save face with an attack on the airfield at Palel, but on 12 July Kawabe gave him an explicit order to break contact with the enemy. The order to retreat reached the divisions on 13 July, and the withdrawal was set for 16 July. By then the commanders of all three divisions had been relieved – the last of them, Lieutenant General Kōtoku Satō, who at the turn of May and June had withdrawn the 31st Division from Kohima against orders, was dismissed on 9 July.

Retreat in the monsoon

The Fifteenth Army withdrew from the field of the Battle of Imphal and Kohima by several routes. The remnants of the 31st and 15th Divisions came down from the hills north-east of Imphal, through the Ukhrul area, towards the Chindwin crossings; Major General Tsunoru Yamamoto’s detachment and the army’s rear services fell back through the Shenam Pass to Tamu and on down the Kabaw Valley; the 33rd Division, the most cohesive of the three, withdrew south along the Tiddim road into the Chin Hills. In the monsoon all these routes were muddy tracks, and the rivers and streams that had to be crossed were in spate.

According to the accounts of Japanese veterans and post-war studies, the retreat became a greater disaster than the offensive itself. Soldiers who had received no rations for weeks abandoned their guns, their vehicles and finally their weapons, keeping only their mess tins in case they managed to find food. They ate grass, roots and mushrooms, some of them poisonous. Men sick with malaria and dysentery collapsed on the tracks, and their bodies, decomposing rapidly in the tropical humidity, marked the way for the columns that followed – hence the Japanese name for the route: “the road of white bones” (hakkotsu kaidō). Many of the wounded and sick who could not be carried killed themselves with grenades so as not to be taken prisoner; survivors’ accounts also speak of the killing of those who could go no further, although some veterans denied such accounts. When the Allies retook Tamu at the end of July, they found there, according to British studies, more than 550 unburied bodies of Japanese soldiers.

Not every unit disintegrated in this way. Major General Shigesaburō Miyazaki, commander of the 31st Division’s covering force, fought delaying actions on the road from Kohima and, according to Japanese accounts, ordered his men to help the living they found on the track and to bury the dead. The main body of the 31st Division received its first substantial supplies only on 9 September, at Pinlebu, far beyond the Chindwin.

Mutaguchi crossed the Chindwin with his headquarters before his divisions did, and around 28 July he left with a few officers for points still further to the rear, at Shwebo, explaining that he needed to arrange food supplies. The officers and men of the divisions regarded this as abandoning the army, and their bitterness towards the Fifteenth Army’s commander outlasted the war. In Japan the defeat was long concealed: after the communiqué of 8 April announcing the capture of Kohima, Imperial General Headquarters said nothing about the operation until the communiqué of 12 August.

Slim’s pursuit

The commander of the British Fourteenth Army, Lieutenant General William Slim, faced a choice: halt his exhausted troops until the end of the monsoon, or pursue the Japanese at once, through rain, mud and malaria. According to Japanese and British studies he decided – on the advice of the commander of IV Corps, Lieutenant General Geoffry Scoones – to give the enemy no time to recover, and around 11 July he ordered the pursuit. It was conducted by Lieutenant General Montagu Stopford’s XXXIII Corps. In August, after Tamu had been retaken, the newly arrived 11th (East Africa) Division – made up of soldiers from Kenya, Uganda, Tanganyika, Nyasaland and Rhodesia – advanced south down the Kabaw Valley, while the 5th Indian Division pushed along the Tiddim road, supplied largely from the air. The flank was covered by the improvised Lushai Brigade, made up partly of local hillmen, which harried the Japanese supply lines.

The pursuit was costly for the victors as well. According to the British official history, also cited in Japanese studies, some 47,000 men of XXXIII Corps fell sick between July and November 1944, more than 20,000 of them with malaria, despite the prophylactic use of mepacrine. Only air superiority and the evacuation of the sick by air allowed the British command to keep up the tempo of operations.

The Japanese no longer had the means to defend themselves. The 33rd Division, which had been fighting on the Tiddim road since March, fell back slowly, fighting action after action for one ridge after another; its rearguards reached the Chindwin at Kalewa only at the end of November. According to the diary of its commander, Lieutenant General Nobuo Tanaka, by the end of June the division had lost 7,000 killed and wounded and 5,000 sick; of the well over ten thousand men who had crossed the border in March, around 2,200 returned to Burma, according to Japanese studies.

The fate of the Indian National Army

Bose’s Indian National Army retreated together with the Fifteenth Army. Its 1st Division, numbering 6,000–7,000 men according to various sources – nearly the entire fighting strength of the force – had covered the flanks of the Japanese columns during the offensive and fought alongside the Yamamoto detachment at Imphal. In the retreat it was even worse supplied than the Japanese. According to estimates cited in the literature, among others by the American historian Peter Ward Fay, the division lost more than half its strength in the offensive and the retreat, and hunger and disease killed several times as many of its men as combat did; many of those who made it back to Burma ended up in hospital. In the battles of Imphal and Kohima and during the retreat nearly 1,500 INA soldiers fell into British hands, some of them deserters.

For a long time Bose refused to accept the retreat. According to the chief of staff of the Burma Area Army, when the Japanese informed him that the operation had been called off, he replied that his soldiers, having set foot on the soil of their homeland, would rather die on it than withdraw. Defeat at Imphal did not, however, put an end to his activity: from the remnants of the INA and new volunteers from Malaya and Burma he formed further divisions, which were still fighting on the Irrawaddy in 1945.

The balance sheet

Japanese losses in the offensive against India are not known precisely, because records have not survived for some of the divisions. According to the British official history, the Japanese lost 54,879 men at Imphal (killed, wounded, sick, missing and captured), including 13,376 killed in action, and a further 5,764 at Kohima; the same official history estimates the total number of killed, died of wounds and disease, and missing at 30,502. In Japan it is most commonly accepted that some 30,000 soldiers died in the operation – most of them not from bullets but from hunger and disease, many of them during the retreat. The Fifteenth Army also lost almost all the horses, mules and cattle of its columns and most of its artillery and vehicles. British and Indian battle casualties amounted, according to British figures, to some 12,600 men at Imphal and more than 4,000 at Kohima.

Place in the war

The defeat had swift consequences for the men in command. On 30 August 1944, eight days later, Mutaguchi and Kawabe were relieved of their posts and recalled to Tokyo; command of the Fifteenth Army passed to Lieutenant General Shihachi Katamura and that of the Burma Area Army to Lieutenant General Heitarō Kimura. Satō, who had wanted to accuse Mutaguchi before a court martial, was declared by doctors unfit to stand trial, and there was no trial.

For the Allies the victory opened the way to the reconquest of Burma. In the north Stilwell’s Chinese and American troops took Myitkyina on 3 August, barring the Japanese Thirty-Third Army’s way north. In the autumn the Fourteenth Army reached the Chindwin: the 5th Indian Division took Tiddim in October and in November linked up with the Africans at Kalemyo, and at the beginning of December the Allies captured Kalewa and seized bridgeheads on the east bank of the river. In December the Viceroy of India, Field Marshal Archibald Wavell, knighted Slim and his corps commanders at a ceremony in Imphal.

The plans for 1945, drawn up at the headquarters of Admiral Louis Mountbatten, provided for a land offensive by the Fourteenth Army across the Chindwin and the Irrawaddy into the plain of central Burma (Operation Capital) and – depending on the availability of landing craft – a seaborne landing at Rangoon (Operation Dracula). The offensive began in December 1944; in the spring of 1945 Slim destroyed the main Japanese forces at Meiktila and Mandalay, and on 3 May 1945 the Allies entered Rangoon. India, which had seemed under threat in 1942 after the fall of Burma and again in 1944 at Imphal, was never again the target of a Japanese offensive for the rest of the war.