The end of the siege of Imphal

On 22 June 1944, on the road from Dimapur to Imphal in the hills of Manipur, the leading units of the British 2nd Division, coming from Kohima, met the 5th Indian Division, which had been fighting its way north out of Imphal. The meeting took place at the stone marking Milestone 109, counting from Dimapur. After almost three months of encirclement IV Corps at Imphal once again had an overland link with India, and that same day and over the following days convoys of lorries set off down the road carrying supplies that could not be delivered by air.

Popular chronologies record the relief of Imphal under 20 June, and under 22 June the end of the Battle of Kohima in a British victory. The first date is two days too early: according to British accounts the two corps linked up on 22 June. The second needs explaining. The fighting on Kohima ridge itself had ended at the turn of May and June, when the Japanese 31st Division began its retreat; British accounts nevertheless date the Battle of Kohima from 4 April to 22 June, because its aim was to open the road to Imphal – and that road was opened at Milestone 109.

The pursuit south from Kohima

The decision of Lieutenant General Kōtoku Satō, who on 31 May began withdrawing his starving 31st Division from Kohima against orders, opened the road south to Lieutenant General Montagu Stopford’s XXXIII Corps. On Kohima ridge, where the garrison had survived the April siege and the relief force had spent the following weeks prising the Japanese out bunker by bunker, nothing remained but a field cemetery and shell-ploughed slopes. The task now was to cover as quickly as possible the more than a hundred kilometres of mountain road separating Kohima from Imphal.

The British 2nd Division advanced along the road itself, while the 7th Indian Division, supplied mainly by mules and jeeps, moved across trackless country to the east to outflank the Japanese positions. They were held up by the 31st Division’s rearguard under Major General Shigesaburō Miyazaki and, further south, by the 60th Regiment of the Japanese 15th Division, which was blocking the road north of Imphal. The Japanese left small groups with machine guns and field guns at bends in the road, blew bridges and culverts, and then fell back to the next position. Each such post had to be outflanked over the forested ridges or taken with heavy artillery support.

The toughest enemy, however, was the monsoon. From the beginning of June it rained almost without pause; landslides buried the road, and jungle paths turned into channels of mud along which the mules could barely move. The men of the 2nd Division, exhausted by two months of fighting for Kohima, suffered from malaria and dysentery. Even so, the pace of the pursuit quickened by the day, because the resistance of the Japanese rearguard was weakening: its soldiers had for weeks been receiving only a fraction of their rations, and no one was bringing up ammunition any more.

Imphal in June

Inside the ring, Lieutenant General Geoffry Scoones’s IV Corps had been counter-attacking since May. Its target was the Japanese 15th Division north and north-east of Imphal – the weakest of the 15th Army’s three divisions. Lieutenant General William Slim, commander of the British Fourteenth Army, judged that if it collapsed the siege would fall apart as soon as XXXIII Corps came up from the north. From the end of May the 5th Indian Division attacked north from Sengmai along the main road through Kanglatongbi, while the 20th Indian Division moved along tracks and up the Iril river valley towards Litan and Ukhrul, threatening the enemy’s supply lines.

In June the Japanese 15th Division was ceasing to exist as a coherent force. Its soldiers were abandoning their positions to look for food in the villages and in their own rear areas. Mutaguchi relieved the mortally ill divisional commander, Lieutenant General Masafumi Yamauchi, and replaced him with Lieutenant General Uichi Shibata, but a change of commander could change nothing. As the 15th Division disintegrated, its 60th Regiment on the Kohima road found itself caught between the two advancing British corps and, according to British accounts, lost most of its strength in the fighting.

In the east, on the Shenam Pass on the road from Tamu, the 23rd Indian Division was beating off attacks by Major General Tsunoru Yamamoto’s force, which had tanks and heavy artillery but was suffering mounting losses. The fiercest fighting was again in the south, at Bishenpur. Lieutenant General Nobuo Tanaka, commander of the Japanese 33rd Division since 22 May, received reinforcements in June – a regiment from the 53rd Division and a detachment of the 14th Tank Regiment – and threw them into another attack on the positions of the 17th Indian Division. After initial success the fresh regiment suffered heavy losses from artillery fire. According to British historiography, by the end of June the 33rd Division was so bled white that it could make no further effort, and many of its battalions had been reduced to handfuls of men.

Imphal itself lived throughout this time on an airlift. Admiral Louis Mountbatten, Supreme Allied Commander of South East Asia Command, had in March diverted to the front some of the transport aircraft intended for China, and for three months American and British aircraft flew in food, ammunition, fuel and reinforcements, flying out the wounded and surplus personnel. The monsoon restricted flying, rations were cut and artillery ammunition had to be husbanded, but the garrison was never in a position like that of the Japanese army on the other side of the front.

The meeting at Milestone 109

Once the last Japanese rearguards had been pushed off the road, the leading elements of the two corps closed on each other from both directions. On 22 June the forward units of the British 2nd Division met the main body of the 5th Indian Division at Milestone 109. The moment itself had nothing of a great battle about it – a few tanks and lorries, soldiers in sodden uniforms – but its significance was obvious to both sides. The Japanese 15th Army, which had set out in March to take Imphal and Kohima, cut off the British front in Assam and open the way into India, had taken neither, and had now lost even control of the road it had been blocking for three months.

For Imphal the reopening of the road meant an end to scrimping. Convoys from Dimapur brought in heavy equipment, ammunition and fuel, and thousands of wounded and sick could leave the town. For Slim it was the signal to pass from defence to pursuit: the two corps could now strike together at the broken Japanese divisions before they could withdraw behind the Chindwin.

The starvation of Mutaguchi’s army

The defeat of the 15th Army was above all a defeat of supply. Lieutenant General Renya Mutaguchi, ignoring the warnings of some of his staff officers, had planned Operation U-Go as if Imphal would fall within three weeks: his soldiers carried rations for about twenty days, and were to take the rest from British depots. Some of the supplies were to be carried by herds of cattle driven over the mountains as a living store of meat; most of the animals died or were lost along the way. When the British held Imphal and Kohima, and the monsoon cut the narrow tracks running back from the Chindwin, the divisions were left without food, medicine or ammunition.

In June this army was starving. Soldiers lived on grass, roots and whatever they could find in abandoned villages; malaria, dysentery, typhus and beriberi killed more men than combat. The wounded and sick who could not walk were left beside the tracks – the Japanese themselves called the route of the later retreat “the road of white bones”. This description is no literary exaggeration: when the Allies retook Tamu at the end of July, according to British accounts they found more than 550 unburied bodies of Japanese soldiers there, with more than a hundred seriously wounded and sick men dying among them.

The Japanese command had long known that the operation would fail. As early as the end of April the Deputy Chief of the General Staff, Lieutenant General Hikosaburō Hata, reported to Tokyo on its gloomy prospects, but Prime Minister Hideki Tōjō brushed these concerns aside. The commander of the Burma Area Army, Lieutenant General Masakazu Kawabe, met Mutaguchi on 6 June; according to accounts, both understood that success was impossible, but neither wanted to take responsibility for ordering a retreat. Kawabe, though ill with dysentery, went on ordering attacks, later explaining that the cause of Subhas Chandra Bose and his Indian National Army, whose units were also fighting at Imphal, depended on the outcome of the operation. Mutaguchi for his part ordered the 31st Division, withdrawn from Kohima, to renew the attack on Imphal from the north together with the 15th Division. Neither was capable of carrying out the order, and neither did.

Burma in the second half of June

Chronologies list an “Allied offensive in Burma” under 21 June. There was no single offensive on that date; there was, however, a series of parallel operations which in the second half of June forced the Japanese onto the defensive along the whole Burma front for the first time since 1942.

In northern Burma General Joseph Stilwell was leading Chinese divisions from Ledo down the Mogaung valley. On 16 June the Chinese 22nd Division took Kamaing. Since May he had also had under his command the Chindits – the brigades flown in behind Japanese lines in March in Operation Thursday and commanded since Orde Wingate’s death by Major General Walter Lentaigne. Stilwell used them as ordinary infantry, although they were worn out by fighting, disease and malnutrition. From the beginning of June Brigadier Michael Calvert’s 77th Brigade, later supported by a Chinese regiment from the 38th Division, was assaulting Mogaung – the railway junction linking the valley with Myitkyina. After fighting for the bridge at Pinhmi, the courthouse and the so-called Red House, British and Chinese units took the railway station on 25 June, and the next day, 26 June, the Japanese abandoned the town. The Chindits regarded Mogaung as the first town in Burma recaptured from the Japanese, although the Chinese had taken Kamaing earlier; according to its commander, the 77th Brigade lost roughly half its strength in the fighting.

A few dozen kilometres further on, the siege of Myitkyina went on. Ever since Merrill’s Marauders had seized the airfield on 17 May, the town’s Japanese garrison, reinforced across the river, had beaten off one Chinese assault after another, while the exhausted Americans were losing men mainly to disease. In the east, in the Chinese province of Yunnan, General Wei Lihuang’s Expeditionary Force, which had crossed the Salween in May, was fighting heavy battles in the mountains for the Japanese fortifications along the Burma Road, above all for Mount Songshan and the approaches to Tengchong and Longling. Only in Arakan, on the coast of the Bay of Bengal, did the monsoon halt major operations on both sides.

All these campaigns had one thing in common: the Japanese in Burma no longer had the reserves to plug every gap at once. General Masaki Honda’s 33rd Army in northern Burma had to defend Myitkyina, Mogaung and the Salween front simultaneously, while Mutaguchi’s 15th Army, which was supposed to decide the outcome of the campaign, was bleeding to death and starving in the hills of Manipur.

Place in the war

The meeting at Milestone 109 closed the Battle of Kohima, but not the Battle of Imphal. Japanese divisions were still in place at Bishenpur and on the Shenam Pass, and Yamamoto’s force even mounted two raids on the airfield at Palel in the first week of July, destroying several aircraft. Only when Mutaguchi understood that none of his divisions was carrying out orders to attack any longer did he call off Operation U-Go on 3 July. The retreat to the Chindwin at the height of the monsoon turned into a catastrophe: shattered units abandoned their artillery, vehicles and wounded, and thousands of soldiers died of hunger and disease along the way. Yamauchi and the commander of the 33rd Division, Genzō Yanagida, were relieved during the battle, and Satō at the beginning of July; in the following months Mutaguchi and Kawabe also lost their posts.

According to figures cited in British historiography, the Japanese lost 54,879 men in the battles of Imphal and Kohima, including 13,376 killed, and most of these losses were caused by hunger, disease and exhaustion; other estimates, which include those who died during the retreat, give a much higher number of dead. British and Indian losses, according to the same sources, came to about 12,600 men, more than 4,000 of them at Kohima. The Japanese also lost almost all the horses and mules of their transport columns, which paralysed several divisions the following year. It is regarded as the greatest defeat the Japanese army had suffered on land up to that time.

The defeat at Imphal changed the situation throughout South-East Asia. Japan no longer had the strength to threaten India, and Bose’s Indian National Army lost credibility as a force that would “liberate” the country. The British Fourteenth Army, which for the first time in the war had destroyed a large Japanese force in open battle, crossed the Chindwin in December 1944, and in the spring of 1945, in the battles of Meiktila and Mandalay, destroyed the main Japanese forces in Burma; on 3 May 1945 the Allies entered Rangoon. In December 1944 the Viceroy of India, Field Marshal Archibald Wavell, knighted Slim and his corps commanders – Scoones, Stopford and Philip Christison, who had fought in Arakan – at a ceremony in Imphal.

On the same day, 22 June, the third anniversary of the German invasion of the USSR, the Red Army launched Operation Bagration in Belarus – at first with reconnaissance in force, the main assault following the next day – while in the Pacific the Americans had been fighting on Saipan for a week, a few days after the Battle of the Philippine Sea. Against this background the end of the siege of Imphal was a less spectacular event, but for the war in Asia it was just as much a turning point. In the Kohima War Cemetery, laid out on the slope of Garrison Hill where the tennis court once stood, there is a memorial to the British 2nd Division bearing the inscription attributed to John Maxwell Edmonds: “When you go home, tell them of us and say, for your tomorrow, we gave our today.” In 2013, in a poll held by the National Army Museum in Britain, the battles of Imphal and Kohima were voted Britain’s greatest battle.