The siege of Imphal and the resulted failure of the Japanese to take Imphal in 1944 was to have a major impact on the war in the Far East. Imphal, along with the unsuccessful attack on the nearby garrison town of Kohima ended the Japanese drive to Delhi. The failure of the Japanese to take Imphal and Kohima also signalled the start of the Allied re-conquest of Burma.
Imphal, the capital of the state of Manipur, is some 70 miles to the west of the Burmese border. To the north of Imphal are the Naga Hills and to the south the Chin Hills - both very difficult areas to use mechanised transport. A metalled road connected Imphal to Kohima to the north and to Moreh, to the southeast, on the Burmese border. During the rainy season the road could be put out of use due to landslides or by simply being washed away. Imphal was also served by tracks used by oxen - but they were a slow mode of transport for the military. Lieutenant-General Sir Geoffrey Evans, commander of the 5th Indian Division that fought at Imphal, stated that during the monsoon season “movement to all intents and purposes ceased “.
After the Japanese attacked and conquered Burma, Imphal took on a major military importance. In May 1942, the Burma Corps, commanded by General Slim, started to arrive in Imphal. Evans described these soldiers “as mere skeletons of their former selves”. If the Japanese had moved swiftly for Imphal then the outcome that was to change the war in the region may have been very different. In fact, the Japanese success in Burma had been so quick that their supplies lines had become overstretched. As a result, they had to halt their advance to reorganise themselves. This gave the military in Imphal the time to organise themselves. The most pressing need was to improve the lines of communications to Imphal so that men and equipment could be moved forward with more ease. Roads and tracks were improved and six new airfields were constructed. Fuel and ammunition dumps were built.
Japanese intelligence concluded that the work being done in and around Imphal was in preparation for a major Allied offensive against the Japanese in Burma. They concluded that Imphal was central to this offensive and to counter it, they would attack and take Imphal. In September 1943, Lieutenant-General Mutaguchi, commander of the Japanese XV Army, was ordered to prepare for 'Operation U-Go' - the capture of Imphal. He had about 100,000 men under his command to complete the task. One month before Mutaguchi's planned attack, the Japanese attacked Arakan in an attempt to draw away some of Imphal's defenders.
On February 4th 1944, the Japanese attack on Arakan started. This put Mutaguchi's force on an effective countdown. The RAF observed Japanese troop movements on the Indian/Burmese border. Documents found on the bodies of two Japanese soldiers near the border showed that they were from a division new to the area. Intelligence photos also showed that a new road had been built to the border and that Japanese tanks been moved there.
The Japanese started their attack on the night of March 7th, as planned. Mutaguchi stirred his men with his order of the day, which was:
“To sweep aside the paltry opposition we encounter and add lustre to army traditions by achieving a victory of annihilation.”
By March 12th various British units based near the Indian/Burma border had been in combat with the Japanese. On March 13th such was the ferocity of the Japanese attacks that these units were given permission to withdraw to the Imphal Plain. General Scoones, commander of the 4th Corps, believed it was better to move his men back rather than face the prospect of them being defeated in battle and being lost to the cause. The withdrawal to the Plain took 20 days.
Allied positions in the area became so threatened that a decision was taken, supported by Mountbatten, to airlift in reinforcements and supplies. Between March 19th and March 29th, the 5th Indian Division was flown in along with artillery guns, jeeps and mules. By the time the first of the 5th's men arrived, the Japanese were only 30 miles from Imphal.
Resolute action by forces at a small hill at Sangshak had far reaching consequences for the Japanese. Though the British had to evacuate the hill on March 26th, leaving behind the wounded and equipment, the fighting done by the 50th Parachute Brigade was sufficient to significantly delay the Japanese advance on Imphal from the northwest. This threw Mutaguchi's timetable into disarray. The 50th Parachute Brigade gave Scoone's an extra two days to organise defences in Imphal. As significant, they had inflicted heavy casualties on the Japanese - far more than Mutaguchi had anticipated.
“The defenders of Sangshak had, in effect, made a valuable contribution to the outcomes of the battle, and although the battalions suffered heavily, it was not long before they were ready for action again.” (Lieutenant-General Evans)
On March 29th, the Japanese cut the Imphal-Kohima road and effectively laid siege to Imphal. The only link to the outside that the defenders had was by air.
The part played by the RAF in the successful defence of Imphal cannot be overstated. During the siege, the RAF delivered 14,000,000 pounds of rations, 1,000,000 gallons of petrol, 43,000,000 cigarettes and 1,200 bags of mail. On the return journey to their bases, RAF aircraft took out 13,000 wounded and 43,000 non-combatants. They also flew in 12,000 reinforcements.
Despite his position, Scoones was not too despondent. Documents taken from Japanese dead indicated that morale among the Japanese was starting to wane and the monsoon was due to arrive, which would make the life of the soldiers out in the open very difficult. Scoones also knew that his men were concentrated while the Japanese had their men more strung out.
However, his confidence was briefly shaken when on April 6th, the Japanese took a hill at Nungshigum, a mere four miles to the north of Imphal itself. Scoones prided himself on the intelligence system he had built up around Imphal but it had failed to detect the totally unexpected arrival of a whole Japanese infantry regiment. Fierce fighting ensued to retake the hill. This was only completed on April 13th but both sides took heavy casualties and the British lost a significant number of officers during this action.
Heavy fighting was also experienced to the southeast of Imphal where the Japanese came up against Ghurkhas and Indian troops of the 20th Division.
Ferocious fighting also occurred to the south of Imphal along the road to Tiddim. Such was the intensity of the fighting that it continued after the siege had actually been lifted. Four of the five Victoria Crosses awarded during the Imphal siege were won here.
The physical condition of the men under his command worried Scoones. They had to get used to dry rations only and this lack of nutrition was very debilitating. The only consolation Scoones had with regard to this was the fact that the very few captured Japanese prisoners that the British had clearly indicated that the Japanese were in a far worse physical state. While the Japanese had got near to Imphal, they were not in a position to actually take the city.
The defenders at Imphal were massively helped when the Japanese were defeated at Kohima as it meant that Allied soldiers based there could move south and attack the Japanese effectively in their rear. Mutaguchi responded by dismissing three of his senior officers, which did little to help morale in the Japanese Army based around Imphal simply because such action had no precedence in the Japanese Army prior to the siege.
On June 22nd British troops formally at Kohima reached men from the 5th Indian Division at a point called Milestone 107 along the Imphal-Kohima road - some twenty miles north of Imphal. It signalled the end of the siege.
On July 18th, the Japanese High Command agreed that a withdrawal was required to the River Chindwin on the Burma side of the Burma/Indian border. The Japanese had sustained 53,000 casualties while the British had lost 17,000 men killed and wounded.
“The disaster at Imphal was perhaps the worst of its kind yet chronicled in the annals of war.” Kase Toshikazu, Japanese Foreign Office official.
General Slim could concentrate his resources on the re-conquest of Burma now that the invincibility of the Japanese Army had been shattered.
“The British, Indian and Ghurkha soldiers stood up to the heavy and incessant strain, largely due to the high standards of leadership, the mutual confidence and friendship between all races and creeds in the Indian divisions, the magnificent work of the medical authorities - and by no means least, to their innate sense of humour in the most adverse circumstances.” (Evans)
Because supplying advancing troops was extremely difficult at best, both Japanese divisions (the XV and XXXI) had to carry a month's food supplies with them. However, there was no flexibility in Mutaguchi's plan. If the time scale went over the planned one month, his men would not only be short of food, but they would hit the monsoon season.