Battle of Imphal

Infobox Military Conflict
conflict=Battle of Imphal


caption=Gurkhas advancing with tanks to clear the Japanese from Imphal-Kohima road [N.E. India]
partof=Burma Campaign
date=8 March - 3 July 1944
place=Imphal, Manipur, India
result=Decisive Allied Victory
combatant1=flagicon|India|British|size=24px Indian IV Corps
combatant2=flagicon|Japan|alt Japanese 15th Army
)
commander1=flagicon|UK William Slim
flagicon|UK Geoffrey Scoones
flagicon|UK Jack Baldwin (air)
commander2=flagicon|Japan|alt Renya Mutaguchi
flagicon|Japan|alt Masakasu Kawabe
flagicon|Japan|alt Kotoku Sato
strength1=4 Infantry Divisions
1 Armoured Brigade
1 Parachute Brigade
strength2=3 Infantry Divisions
1 Tank Regiment
casualties1=17,500 killed and woundedLouis Allen, "Burma: The Longest War", p. 638]
casualties2=53,879 killed and wounded

The Battle of Imphal took place in the region around the city of Imphal, the capital of the state of Manipur in North-East India from March until July 1944. Japanese armies attempted to destroy the Allied forces at Imphal and invade India, but were driven back into Burma with heavy losses. Together with the simultaneous Battle of Kohima on the road by which the encircled Allied forces at Imphal were relieved, the battle was the turning point of the Burma Campaign, part of the South-East Asian Theatre of World War II.

The situation

At the start of 1944, the war was going against the Japanese on several fronts. They were being driven back in the central and south west Pacific. In south east Asia, they had held their lines over the preceding year, but the Allies were preparing several offensives from India and Yunnan into Burma. In particular, the town of Imphal in Manipur on the frontier with Burma was built up to be a substantial logistic base, with airfields, encampments and supply dumps.

Imphal was held by the Indian IV Corps, commanded by Lieutenant-General Geoffrey Scoones. The corps was in turn part of the British Fourteenth Army under Lieutenant General William Slim. Because the Allies were planning to take the offensive themselves, the corps' units were thrown forward almost to the Chindwin River and widely separated, being vulnerable to being cut off.

*Indian 20th Infantry Division occupied Tamu. The division was untried but well-trained.
*Indian 17th Infantry Division occupied Tiddim, at the end of a long and precarious line of communication. The division, which had two brigades only, had been intermittently in action since December 1941.
*Indian 23rd Infantry Division was in reserve in Imphal. It had served on the Imphal front for two years and was severely understrength as a result of endemic diseases such as malaria and typhus.
*Indian 50th Parachute Brigade was north of Imphal, conducting advanced jungle training.
*254th Indian Tank Brigade was stationed in and around Imphal.

Japanese plan

Late in 1943, the Japanese command in Burma had been reorganised. A new headquarters, Burma Area Army, was created under Lieutenant-General Masakasu Kawabe. One of its subordinate formations, responsible for the central part of the front facing Imphal and Assam, was Fifteenth Army, whose new commander was Lieutenant-General Renya Mutaguchi.

From the moment he took command, Mutaguchi forcefully advocated an invasion of India. His motives for doing so appear to be complex.He had played a major part in several Japanese victories, ever since the Marco Polo Bridge incident in 1937 and believed it was his destiny to win the decisive battle of the war for Japan. He may also have been goaded by the first Chindit expedition, a raid behind Japanese lines launched by the British under Orde Wingate early in 1943. The Allies had widely publicised the successful aspects of Wingate's expedition while concealing their losses to disease and exhaustion, possibly misleading Mutaguchi and some of his staff as to the difficulties they would later face.

Mutaguchi planned to exploit the capture of Imphal by advancing to the Brahmaputra River valley, thereby cutting the Allied supply lines to their front in northern Burma, and to the airfields supplying the Nationalist Chinese under Chiang Kai-shek over "The Hump". Although the staff at Burma Area Army HQ and at Southern Expeditionary Army Group HQ had reservations over the scale of his proposed operation, they were eventually induced to support it when War Minister Hideki Tojo and Imperial Army HQ favoured attacking India.

Mutaguchi intended to cut off and destroy the Allied units in their forward positions and then capture Imphal. His plan was name U-Go, or Operation C. In detail:
*The Japanese 33rd Infantry Division under Lieutenant-General Motoso Yanagida would destroy the Indian 17th Division at Tiddim, then attack Imphal from the south.
*"Yamamoto Force", formed from units detached from the Japanese 33rd and 15th Divisions under Major-General Tsunoru Yamamoto (commander of 33rd Division's Infantry Group), would destroy the Indian 20th Division at Tamu, then attack Imphal from the east. The force was supported by the 14th Tank Regiment, equipped with 66 assorted tanks, under Lieutenant Colonel Nobuo UedaLouis Allen, "Burma:The Longest War", pp.221-224] and the 3rd Heavy Artillery Regiment under Lieutenant Colonel Kazuo Mitsui.
*The Japanese 15th Infantry Division under Lieutenant-General Masafumi Yamauchi would envelop Imphal from the north. This division was still arriving from road-building duties in Thailand and was understrength at the start of the operation.
*In a separate subsidiary operation, the Japanese 31st Infantry Division under Lieutenant-General Kotoku Sato would isolate Imphal by capturing Kohima, then exploit to Dimapur.

At the insistence of Subhas Chandra Bose, leader of the Azad Hind, the Indian National Army made a substantial contribution. (Originally, the Japanese intended using them only for reconnaissance and propaganda.)
*Units of the First Division (initially the Subhas Brigade or 1st Guerrilla Regiment, less a battalion sent to the Arakan), and later the 2nd Guerrilla Regiment, were directed along Tamu road as part of "Yamamoto Force". [Harvnb|Fay|1993|p=285]
*The Special Services Group, redesignated as the "Bahadur Group" acted as scouts and pathfinders with the advanced Japanese units in the opening stages of the offensive. They were tasked to infiltrate through British lines and encourage units of the British Indian Army to defect. British Intelligence sources confirmed that these units achieved some success in the early stages of the Japanese offensive. [Harvnb|Fay|1993|p=296]

All Mutaguchi's divisional commanders disagreed with the plan to some extent. Sato distrusted Mutaguchi's motives, and Yanagida openly derided him as a "blockhead." Yamauchi was already very ill and fatalistic. [Louis Allen, "Burma: The Longest War", p.164] Their main reservations concerned supply. Mutaguchi had assumed success within three weeks, but adequate supplies after that period could be obtained only if the Japanese captured Allied supply dumps, as the torrential rains that the spring season would inevitably bring would make supply routes from the east impossible to traverse. Gambles such as Mutaguchi was making had worked in the past, but could no longer be relied upon to work, given nearly total Allied air superiority in the area and the improvement in morale and training of British and Indian troops. Mutaguchi proposed using "Genghis Khan" rations, driving herds of buffalo and cattle across the Chindwin as meat rations on the hoof. Most of these unfortunate beasts died from lack of forage and rotted many miles from the troops they were intended to supply.

There were other weaknesses in the plan which were to be revealed as the campaign progressed. The Japanese assumed that the British would be unable to use tanks on the steep jungle-covered hills around Imphal. For the sake of ease of movement and supply, the Japanese were leaving behind most of their field artillery, their chief anti-tank weapon. As a result, the Japanese troops would have very little protection against tanks if these were in fact used against them.

Based on his experiences in the campaigns in Malaya and Singapore and in Burma in early 1942, Mutaguchi dismissed British and Indian troops as inherently inferior. The troops he had met on those occasions had generally been inadequately trained and led. The Allies had by now largely overcome the administrative and organisational problems which had crippled their early efforts in Burma, and their troops were far better trained and motivated.

Prelude to the operation

In late February, a local Japanese counter-attack was launched against Indian XV Corps in Arakan, using much the same tactics as Mutaguchi proposed to use. The attack failed when Allied aircraft parachuted supplies to cut-off troops, allowing them to stand firm while the Japanese ran out of supplies. The engagement became known to the Allies as the Battle of the Admin Box. From this point onwards, the Allies were to place increasing faith and reliance on their transport aircraft. The planning of Operation C was too far advanced to take account of these developments.

Even as the Japanese prepared to launch their attack, on 5 March 1944 the Allies launched the airborne phase of the second Chindit expedition. Japanese officers such as Major-General Noburo Tazoe, commanding the Japanese Army Air Force units in Burma, urged Mutaguchi to divert troops from his offensive to secure the Japanese rear areas against the Chindits. Mutaguchi dismissed these concerns, claiming that in a few weeks he would have occupied the air bases from which the Chindits were supplied.

When they received intelligence that a major Japanese offensive was impending, Slim and Scoones planned to withdraw into the Imphal plain and force the Japanese to fight with their logistics stretched beyond the limit. However, they misjudged the date on which the Japanese were to attack, and the strength they would use against some objectives.

The battle

Opening phases

The Japanese launched their troops across the Chindwin River on March 8. Scoones only gave his forward divisions orders to withdraw to Imphal on March 13.

The Indian 20th Division under Major-General Douglas Gracey withdrew from Tamu without difficulty, mainly because two of Yamamoto's battalions from the Japanese 15th Division were delayed at Indaw in northern Burma by the Chindits and were unable to intervene. Further south, the Indian 17th Division under Major-General Cowan was cut off by the Japanese 33rd Division. The Japanese 215 Regiment captured a supply dump at Milestone 109, twenty miles behind Cowan's leading outposts. The Japanese 214 Regiment seized Tongzang and a ridge named Tuitum Saddle across the only road, a few miles behind the Indian 17th Division's position.

At Tuitum Saddle, 214 Regiment were unable to dig in properly before they were hit by the Indian 48th Brigade on March 18. The Japanese suffered heavy casualties and were forced away from the road. Fighting around Milestone 109 was even more severe, but Cowan had taken steps to secure the most vulnerable point in the rear of his division, the bridge over the Manipur River. 17th Division crossed safely, demolishing the bridge behind them, and recovered the depot on March 25. They were forced to abandon large amounts of supplies, but removed most of the vehicles, food and ammunition. The Japanese were left only such items as clothing and blankets.

Scoones had nevertheless been forced to send the bulk of his only reserve, Indian 23rd Infantry Division under Major-General Ouvry Lindfield Roberts, to the aid of 17th Division. The two divisions, now supplied by parachute drops from Allied aircraft, made their way back to the Imphal plain, which they reached on April 4.

Meanwhile, Imphal had been left vulnerable to the Japanese 15th Division. The only force left covering the base, Indian 50 Parachute Brigade, was roughly handled at Sangshak by a regiment from the Japanese 31st Division on its way to Kohima. The 31st Division had also blocked the main road south of Kohima by the start of April, cutting off IV Corps. However, an earlier diversionary attack launched by Japanese 55th Division in Arakan had already failed. Slim was able to move the battle-hardened Indian 5th Infantry Division, including all its artillery and transport, by air from Arakan to the Central Front. The move was completed in only eleven days. Two of its three brigades went to Imphal, and their leading troops were in action on April 3.

On the Japanese left flank, the INA's Subhas Brigade, led by Col. Shah Nawaz Khan, reached the edge of the Chin Hills below Tiddim and Fort White at the end of March. From this position, the 2nd Battalion sent companies to relieve Japanese forces at Falam and to Hakha, from where in turn, Khan's forces sent out patrols and laid ambushes for the Chin guerrillas under the command of a British officer, taking a number of prisoners. In the middle of May, a force under Khan's Adjutant, Mahboob "Boobie" Ahmed, attacked and captured the hilltop fortress of Klang Klang. [Harvnb|Fay|1993|p=286,287] The 3rd Battalion meanwhile moved to Fort White-Tongzang area in anticipation of the destruction of Cowan's division, which would allow it to receive volunteers.

talemate

From the beginning of April, the Japanese attacked the Imphal plain from several directions:

*33rd Division attacked from the south at Bishenpur, where they cut a secondary track from Silchar into the plain. Yanagida, its commander, was already pessimistic and depressed by the failure to trap the Indian 17th Division. He had also been rattled by a garbled radio message which suggested that one of his regiments had been destroyed at Milestone 109. He therefore advanced cautiously. By doing so, he may have lost a chance to gain success while the Indian 17th Infantry Division was resting after its retreat and Bishenpur was held only by Indian 32 Brigade (from 20th Division). Mutaguchi removed him from command.
*"Yamamoto Force" attacked the Shenam Saddle on the main road from Tamu into Imphal. The Shenam Saddle was ideal defensive terrain. Despite using heavy artillery and tanks, Yamamoto could not break through Indian 20th Division's well-sited defences. The INA's Gandhi Regiment or 2nd Guerrilla Regiment, of two battalions led by Inayat Kiyani, later joined this attack and suffered heavy casualties in the assault on Palel airfield.
*15th Division encircled Imphal from the north. Its 60 Regiment captured a British supply dump at Kangpokpi (also known as "Mission" from a church there) on the main Imphal-Dimapur road, but once again, the depot had already been emptied of food and ammunition. 51 Regiment seized the vital Nunshigum Ridge, which overlooked the main airstrip at Imphal. This was a major threat to IV Corps, and on April 13 the Indian 5th Division counter-attacked, supported by massed artillery and the M3 Lee tanks of the 3rd Carabiniers. The Japanese regiment had no anti-tank weapons, and their troops were driven from the ridge with heavy casualties.

Allied counter-attacks

By May 1, all Japanese attacks had come to a halt. Slim and Scoones now began a counter-offensive against the Japanese 15th Division. This division was the weakest of the Japanese formations, and success against it would break the siege. Progress was slow. The monsoon had broken, making movement very difficult. Also, IV Corps was suffering some shortages. Although rations and reinforcements were delivered to Imphal by air, artillery ammunition was by now rationed. The steep ridges held by the Japanese were almost impregnable.

However, the Japanese were at the end of their endurance. Neither the Japanese 31st Division which was fighting at Kohima, nor 15th Division, had received adequate supplies since the offensive began, and their troops were starving. This allowed Indian XXXIII Corps to drive the Japanese from Kohima at the end of May, and advance south.

The troops of Japanese 15th Division were forced to abandon their defensive positions to forage for supplies in local villages. Mutaguchi dismissed the mortally ill Yamauchi, but this did not change matters. After driving rearguards from the "Miyazaki Group" (an independent detachment from the 31st Division) and the Japanese 60 Regiment from their delaying positions, the leading troops of IV Corps and XXXIII Corps met at Milestone 109 on the Dimapur-Imphal road on June 22, and the siege was raised.

Although there was now no realistic hope of success, Mutaguchi (and Kawabe) ordered renewed attacks. 33rd Division had been reinforced by a regiment from the 53rd Division and a battalion from the 54th Division. Under a new forceful commander, Lieutenant-General Nobuo Tanaka, the division broke into the Indian 17th Division's positions at Bishenpur, but failed to break through. Yamamoto Force also made repeated efforts, but by the end of June both formations had suffered so many casualties that they were unable to make any progress. 15th and 31st Divisions refused to make a renewed attack on Imphal from the northeast, as they were in no condition to comply.

Towards the end of May, the INA's 1st Guerrilla Regiment had been redirected to Kohima. Khan moved north across the Japanese rear but by the time he reached Ukhrul, the Japanese had already begun to withdraw. Khan decided to attack Imphal instead. At Imphal, his unit suffered some desertions, but not in the scale as the Commonwealth forces expected. [Harvnb|Fay|1993|p=287]

End

In fact, the Japanese had realised that operations ought to be broken off as early as May. At a meeting between Mutaguchi and Kawabe on 6 June, both used "haragei", an unspoken form of communication using gesture, expression and tone of voice, to convey their conviction that success was impossible. But neither of them wished to bear the responsibility of ordering a retreat. Kawabe subsequently became ill with dysentery and perhaps physically unfit for duty. He nevertheless ordered repeated attacks, stating later that Bose was the key to Japan's and India's future. [Allen, "Burma: The Longest War, p.310]

When he realised that none of his formations were obeying his orders for a renewed attack, Mutaguchi finally ordered the offensive to be broken off on July 3. The Japanese, reduced in many cases to a rabble, fell back to the Chindwin river, abandoning their artillery, transport, and soldiers too sick to walk. The defeat at Kohima and Imphal was the largest defeat to that date in Japanese history. They had suffered 55,000 casualties, including 13,500 dead. Most of these losses were the result of starvation, disease and exhaustion. By contrast, the Allies suffered 17,500 casualties. Both Kawabe and Mutaguchi were relieved of command.

Air Operations at Imphal

By mid-1944, the Allied air forces enjoyed undisputed air supremacy over Burma. The last major effort by the Japanese Army Air Force had been over the Arakan in February and March, when they had suffered severe losses. During the Imphal and Kohima battles, they were able to make barely half a dozen significant raids.

IV Corps enjoyed close air support from fighter-bombers and dive bombers. Allied fighter bombers and medium bombers shot up and bombed enemy concen­trations, supply dumps, transport, roads and bridges all the way to the Chindwin river. The monsoon in no way diminished their activity. The Third Tactical Air Force (TAF) increased their sortie rate to 24,000 sorties during the worst four months of the monsoon, nearly six times the figure of the previous year’s record.

However, the most important contribution to the Allied victory was made by both British and American transport aircraft. The Allies could fly men, equipment and supplies into the airstrips at Imphal (and Palel also, until the onset of the monsoon rains) so although cut off by land, the town was not without a lifeline. Allied aircraft could also parachute ammunition, rations and even drinking water to surrounded units.

Several thousand mules, many shipped from the Argentine, were used to carry food ammunition, and light guns to outlying outposts, for example 17th Indian Division up the Bishenpur trail. During the siege animal fodder also had to be flown in.

At the start of the battle, South East Asia Command had 76 transport aircraft (mainly C-47 Skytrain) available, but many others were dedicated to supplying the Nationalist Chinese under Chiang Kai-Shek, or to establishing USAAF bomber bases in China, via "the hump". Not even Lord Mountbatten, the Commander-in-Chief, had the authority to commandeer any of these aircraft, but at the crisis of the battle in the middle of March he nevertheless did so, acquiring 20 C-46 Commando. He was supported by American officers at SEAC and the American China-Burma-India Theater headquarters. [Louis Allen, "Burma: The Longest War", p.243]

By the end of the battle the Allied air forces had flown 19,000 tons of supplies and 12,000 men into Kohima and Imphal, and flown out 13,000 casualties and 43,000 non-combatants.

War Cemetry

After the war, the Commonwealth War Graves Commission set up cemetries in Imphal and Kohima to commemorate the memories of the British and the Indian soldiers who died during the Second World War. [http://www.wikimapia.org/#lat=24.8227348&lon=93.9463824&z=18&l=0&m=a&v=2]

Bibliography

* Jon Latimer, "Burma: The Forgotten War", London: John Murray, 2004. ISBN 978-0719565762
* William Slim, "Defeat Into Victory", London: Cassell, 1956.
* Don Moser and editors of Time-Life Books, "World War II: China-Burma-India", (1978), Library of Congress no 77-93742
* Louis Allen, "Burma: The longest War", Dent Publishing, 1984, ISBN 0-460-02474-4
*Harvard reference
Surname1 = Fay
Given1 = Peter W.
Year = 1993
Title = The Forgotten Army: India's Armed Struggle for Independence, 1942-1945.
URL =
Publisher = Ann Arbor, University of Michigan Press.
ISBN = 0472083422 .

Notes

External links

* [http://www.burmastar.org.uk/Imphal-map.gifBurma Star Association] Map
* [http://www.burmastar.org.uk/imphal1.htm Burma Star Association ] Japanese invade India
* [http://www.remuseum.org.uk/corpshistory/rem_corps_part16.htm#india2 Royal Engineers Museum] Engineers at Imphal and Kohima
* [http://www.national-army-museum.ac.uk/pages/Second-war/far-east.html National Army Museum] War in the Far East
* [http://www.aircraftresourcecenter.com/Fea1/701-800/Fea747_Hurricane_Rao/fea747.htm No. 1 Squadron, Royal Indian Air Force, Imphal, Assam, 1944]
* [http://www.psywarsoc.org/timeline/japanese.php British leaflet dropped post-Imphal in Burma]