The pursuit to the Irrawaddy

War chronologies record under 5 January 1945 that the Japanese in Burma were withdrawing behind the Irrawaddy and that General Slim’s forces were in pursuit. The entry does not refer to a single battle or a single day – it sums up a process that lasted from December 1944 to mid-January 1945. The main forces of the Japanese Fifteenth Army had crossed to the eastern bank of the Irrawaddy as early as December and around the turn of the year; on the western bank, on the Shwebo plain, only rearguards remained, delaying the enemy’s advance for several more weeks. Nor was the withdrawal the flight of a broken army; it was the deliberate decision of the new Japanese commander in Burma, who had resolved to accept the decisive battle only behind the broad river.

For Lieutenant General William Slim’s British Fourteenth Army, it was the first advance into central Burma since 1942 – into the country from which, in May of that year, its predecessors had retreated to India after the loss of Mandalay. Now, half a year after the Japanese defeat at Imphal and Kohima, the Allies were coming back the same way in the opposite direction.

After Imphal

The Japanese offensive against India had ended in disaster in the summer of 1944. After the siege of Imphal was broken in June, the remnants of the Fifteenth Army retreated through the monsoon towards the Chindwin, losing thousands of men to hunger and disease; by August there were no longer any coherent Japanese forces on Indian soil, which marked the end of the Japanese invasion of India. According to the British official history, some 30,000 Japanese soldiers were killed or died in the whole operation – the Battle of Imphal and Kohima. The commander of the Fifteenth Army, Lieutenant General Renya Mutaguchi, and the commander of Burma Area Army, Lieutenant General Masakazu Kawabe, were recalled at the end of August.

Burma Area Army was taken over by Lieutenant General Heitarō Kimura, previously Vice-Minister of War in Hideki Tōjō’s government, an artilleryman and a specialist in industrial mobilisation. Tokyo hoped he would make the forces in Burma self-sufficient, relying on Burmese rice, factories and oilfields. His chief of staff was Lieutenant General Shin’ichi Tanaka, former commander of the 18th Division, which had fought the Chinese and Americans in the north. The Fifteenth Army was taken over by Lieutenant General Shihachi Katamura.

Kimura inherited a shattered army. According to British studies, his staff set a reduced strength of 10,000 men for the divisions in Burma instead of the establishment of nearly 25,000, and most divisions did not have even half that number; replacements were conscripts of lower medical categories. Anti-tank weapons, artillery and transport were all lacking. The Japanese air force in Burma (the 5th Air Division) numbered a mere few dozen aircraft against some 1,200 Allied ones. Field Marshal Hisaichi Terauchi’s Southern Army allotted several tens of thousands of replacements to Burma, but Allied raids on the Burma Railway and the port of Rangoon meant that only some of them reached the country.

Kimura’s plan: a battle behind the river

The Allies assumed that the Japanese would, as before, make their stand as far west as possible – on the Chindwin or on the Shwebo plain between the Chindwin and the Irrawaddy. Kimura, however, concluded that his weakened divisions stood no chance in open country against British and Indian armoured and motorised units and an air force that ruled the skies. He decided to give up the plain without a fight and withdraw the Fifteenth Army behind the Irrawaddy, where the broad river would halt the enemy and the Fourteenth Army’s lengthening supply lines would weaken it before the decisive battle. This operation was called Ban; in Japanese historiography the coming fighting in central Burma is known as the Battle of the Irrawaddy.

At the same time Lieutenant General Shōzō Sakurai’s Twenty-Eighth Army was to defend the Arakan coast and the lower Irrawaddy valley (Operation Kan), and the Thirty-Third Army in the north was to delay the opening of the land route from India to China by holding Bhamo and Lashio (Operation Dan). The Fifteenth Army, with the 15th, 31st and 33rd Divisions, took up positions on the eastern bank of the Irrawaddy from the Mandalay area to Pakokku; the 53rd Division formed the Area Army’s reserve. On the western bank the Japanese kept only a bridgehead in the hills at Sagaing, opposite Mandalay, and rearguards in the small towns of the Shwebo plain.

Operation Capital

On the Allied side, the shape of the 1945 campaign was determined by Admiral Louis Mountbatten’s South East Asia Command at Kandy in Ceylon. Three options were considered: an offensive confined to northern Burma to complete the Ledo Road to China; a seaborne landing at Rangoon; and finally a great land offensive by the Fourteenth Army across the Chindwin into central Burma. The landing, named Dracula, was approved by the Combined Chiefs of Staff at the Quebec Conference, but the landing ships and carriers could not arrive before the end of the war in Europe. The main operation therefore became the land offensive code-named Capital, whose objective was Mandalay and a link-up with the American and Chinese forces in the north.

The Fourteenth Army consisted of Lieutenant General Frank Messervy’s IV Corps (he had replaced Lieutenant General Geoffrey Scoones in December) and Lieutenant General Montagu Stopford’s XXXIII Corps. It was a multinational army to a degree rarely found on other fronts. Most of its soldiers came from the Indian Army – among them Punjabis, Sikhs, Rajputs, Dogras, Madrassis and Gurkhas from Nepal – and alongside the Indian divisions (the 5th, 7th, 17th, 19th and 20th) fought the British 2nd Division. From Africa came the 11th (East Africa) Division, made up of soldiers from Kenya, Uganda, Tanganyika, Nyasaland and Northern Rhodesia, and the 28th East African Brigade; in Arakan, as part of Indian XV Corps, the 81st and 82nd (West Africa) Divisions from Nigeria, the Gold Coast, Sierra Leone and the Gambia were fighting. British replacements were becoming ever scarcer, so in 1945 the burden of the fighting rested more and more on Indian, Gurkha and African soldiers.

In the autumn, as the monsoon was ending, the Fourteenth Army reached the Chindwin. The 11th (East Africa) Division, pursuing the Japanese down the Kabaw valley, took Kalewa at the beginning of December, and the sappers built a Bailey bridge about 350 metres long across the river there – according to British accounts, the longest bridge of its kind in the world at the time. Two divisions set out from the bridgeheads on the Chindwin: Major General Thomas “Pete” Rees’s Indian 19th Division from the northern crossings at Sittaung and Mawlaik, and Major General Douglas Gracey’s Indian 20th Division from the Kalewa bridgehead on 4 December. Both advanced quickly, almost unopposed; in mid-December, near Banmauk, the 19th Division joined hands with the British 36th Division, advancing from the north under the American Northern Combat Area Command, which for the first time linked the Fourteenth Army’s front with the northern front, where Myitkyina had been taken in August.

A change of plan

It was the very ease of this advance that worried Slim. In the second half of December he concluded that the Japanese did not intend to fight on the Shwebo plain, and that a drive by both corps on Mandalay would strike into a void and then rebound off the fortified line of the Irrawaddy. So he changed his plan in mid-operation. XXXIII Corps, reinforced by the 19th Division transferred from IV Corps, was to go on clearing the Shwebo plain, cross the Irrawaddy north and west of Mandalay and tie down the main Japanese forces in the fight for the city. IV Corps, shifted from the left flank to the right, was to move south in secret down the Gangaw valley west of the Chindwin, cross the Irrawaddy near Pakokku and seize Meiktila with a swift armoured thrust – the main rail, road and airfield hub through which supplies flowed to all the Japanese forces fighting around Mandalay. The new plan was named Extended Capital; it also covered the later pursuit to Rangoon.

Success depended on surprise. So that the Japanese would go on believing that IV Corps was heading for Mandalay, a dummy corps headquarters was left behind at Sittaung, through which all radio traffic with the 19th Division was passed. The march of the Indian 7th Division down the Gangaw valley was screened by light forces – the 28th East African Brigade and the improvised Lushai Brigade. The Japanese, deprived of air reconnaissance and ever more poorly informed by a Burmese population no longer well disposed towards them, failed to notice the shift of an entire corps.

A war of supply

The Fourteenth Army’s greatest enemy was distance. Its troops were moving hundreds of kilometres away from the railhead at Dimapur in Assam, along mountain roads that turned to mud in the monsoon; at one point, according to British studies, IV Corps’ columns stretched from Pauk all the way back to Kohima, over a distance of some 560 kilometres. The sappers surfaced the roads with strips of jute soaked in bitumen and diesel oil, and at Kalewa boats and barges were built of local teak to float supplies down the Chindwin; Slim later described this improvised flotilla with evident pride.

The principal means of supply, however, was the air. The Anglo-American Combat Cargo Task Force, flying mainly Douglas C-47s, dropped food, ammunition and fuel or flew them into field airstrips, taking the sick and wounded back on the return flight. Combat support came from No. 221 Group RAF, with Hurricane and Thunderbolt fighters, Mitchell bombers and Beaufighters. This system was fragile: in December 1944 the Americans moved two Chinese divisions from Burma to China, and on 16 December they suddenly took 75 transport aircraft away from the Fourteenth Army to save Kunming from the Japanese offensive in Guangxi, part of Operation Ichi-Go. The British brought in aircraft from the Mediterranean, but the threat of losing the American transports hung over Slim throughout the campaign. That is why the airfields on the Arakan coast were so important: supplies brought in by sea could be flown on from there to central Burma.

January on the Shwebo plain and in Arakan

At the beginning of January 1945 XXXIII Corps was clearing the Shwebo plain of Japanese rearguards. The fighting was brief but fierce – the Japanese delaying detachments defended villages and road junctions to the last man, giving their main forces time to organise the defence behind the river. The Indian 19th Division reached the outskirts of Shwebo on 7 January and took the town on 9 January; some accounts, among them the history of the British 2nd Division, which was approaching from the west, give 11 January as the date of its capture. The Indian 20th Division fought a harder battle for the river port of Monywa on the Chindwin, taken on 22 January. The Japanese held on only to the bridgehead at Sagaing.

Before the whole plain had been cleared, the 19th Division put its first units across the Irrawaddy: on 14 January at Thabeikkyin, and the next day at Kyaukmyaung, about 65 kilometres north of Mandalay. The river was narrower there than in its lower course. For the following weeks the reinforced Japanese 15th Division tried in vain to drive both bridgeheads into the water – which was just what Slim wanted, since every Japanese regiment drawn to Kyaukmyaung would be missing later at Meiktila.

On the Arakan coast, Lieutenant General Philip Christison’s Indian XV Corps was advancing for the third year running on the island and port of Akyab (Sittwe), with its important airfield. The two West African divisions, moving down the Kaladan and Kalapanzin valleys, threatened the Japanese supply lines, while the Indian 25th Division came down to the tip of the Mayu peninsula. The Japanese evacuated Akyab on 31 December 1944, and on 3 January 1945 the 3rd Commando Brigade landed on the island unopposed. Further landings followed: on 12 January on the Myebon peninsula, on 21 January on Ramree Island (the Battle of Ramree Island lasted six weeks) and on 22 January at Kangaw, where commandos and Indian troops fought some of the hardest battles of the campaign for a week.

People and politics

The Irrawaddy campaign was fought in a country whose people were less and less well disposed towards the occupier. In 1942 many Burmese had welcomed the Japanese as liberators from British rule. But the formally “independent” State of Burma under Ba Maw and Aung San’s Burma National Army remained under Japanese control, and requisitions, forced labour and poverty had alienated the population. Aung San was already in contact with Thakin Soe’s communists and preparing to turn against the Japanese; at the beginning of 1945 he approached the British organisation Force 136, which had earlier supported the guerrillas among the Karens. Also fighting on the Japanese side was Subhas Chandra Bose’s Indian National Army, made up of former prisoners from the Indian Army and volunteers from among the Indians living in Malaya and Burma; some of its units fought doggedly in 1945, while others surrendered or went over to the Allies.

The civilian population paid a high price for the campaign: the towns and villages of central Burma, the rearguards defending them and the communication hubs were targets of Allied air raids and shelling, and both sides requisitioned food and draught animals. The number of civilian victims of this phase of the war in Burma is unknown.

Place in the war

The pursuit at the turn of 1944 and 1945 was the prelude to the most successful British operation of the war against Japan. Kimura’s decision to fight only behind the Irrawaddy was sensible given the weakness of his army, but it made it easier for Slim to change his plan: instead of a frontal assault on a prepared river line, the Fourteenth Army could pin the Japanese down in battle around Mandalay and strike at their rear. In mid-February the 20th Division crossed the Irrawaddy west of Mandalay, and the 7th Division at Nyaungu and Pagan, in a crossing that Slim later called the longest opposed river crossing attempted in any theatre of the Second World War. The 17th Division, with the 255th Armoured Brigade, passed through the 7th Division’s bridgehead and took Meiktila at the beginning of March. The Japanese counter-attacks on the town broke down, on 20 March British and Indian troops took Fort Dufferin in Mandalay, and the remnants of Kimura’s army fell back south. On 27 March Aung San’s Burma National Army turned against the Japanese, and on 3 May 1945, in the last days before the monsoon broke, the Allies entered Rangoon – taken from the sea in Operation Dracula a few days after the Japanese had left it.

In the north, meanwhile, the land link with China was being completed: in January 1945 the first convoy set off along the Ledo Road, and at the end of the month the joined-up road, named after General Joseph Stilwell, was opened; this coincided with the end of the Salween offensive. Kimura, promoted to full general in 1945, was tried after Japan’s surrender by the International Military Tribunal for the Far East; he was found, among other things, to share responsibility for the treatment of prisoners of war in Burma, and was hanged on 23 December 1948. Slim described the campaign in his memoir Defeat into Victory (1956), regarded as one of the finest accounts by a commander of that war. For the soldiers of the Fourteenth Army – called “the Forgotten Army” because its battles remained in the shadow of the European fronts – January 1945 was the moment when, after three years of retreat and defence, they at last advanced deep into the country lost in 1942.