1. Kohima-Imphal March 8-July 8, 1944
Strategic Context
As the Japanese run amok across the Pacific attacking Allied forces, the British are thrown out of Burma twice in two years. While the Americans begin rolling back the Japanese in the Pacific, the British still stand on the defensive in India. The Japanese 15. Army is much larger and advancing more quickly than the British expected. However, the self-proclaimed invincible Japanese outrun their supply lines and must now capture British supplies before pushing further into India. Joseph Stillwell defeats the Japanese 28. Army in the north at Arakan, freeing up reinforcements for William Slim’s 14. Army, which must survive until they can be brought into battle.
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Stakes
+ A Japanese victory would capture enough British supplies for a thrust into India while closing the Burma Road, therefore cutting off material aid to China indefinitely.
+ A British victory would remove the threat to India while reopening the Burma Road, increasing material aid to China.
By Jonathan Webb, 2009

2. Kohima-Imphal, 1944 Strength
Japanese 15. Army
Well
British 14. Army
Well
Renya Mutaguchi
William Slim
100,000
155,000
By Jonathan Webb, 2009

3. East Asia & Pacific c. Nov 1943

4. British 14. Army Japanese 15. Army
The battlefield features dense, swampy jungle and constant changes in elevation. Movement is especially restricted travelling east-west as most of the major rivers and ridges run north-south, the most significant obstacle being the Chindwin River. The only open, flat areas are just east of the Chindwin River and the Imphal Plain. The most significant urban features are Kohima and Imphal, the objectives of the Japanese. The real key terrain though is Dimapur to the northwest, which sits along on the vital railroad for supply.
British 14. Army
(Slim)
Pheru River
Naga Hills
Dimapur
Kohima
Imphal
Yu River
Imphal Plain
Chindwin River
Irang River
Tengnoupal Ridge
Manipur River
Kabaw Valley
Tuivai River
Japanese 15. Army
(Mutaguchi)

5. Japanese 15. Army British 14. Army
Mutaguchi deploys his three divisions behind the Chindwin River; he plans to besiege and capture Kohima with the 31st Infantry Division (ID) and Imphal with the 15th and 33rd IDs. Slim expects only a regiment-sized attack on Kohima and only places the 50th Parachute Brigade (Bde) there. Slim plans to lure Mutaguchi into a battle of attrition on the Imphal Plain where British superiority in tanks, artillery and airpower can annihilate the lighter-equipped Japanese. He places the Indian 17th, 20th, 23rd IDs, and the 254th Tank Bde there. Meanwhile, the Indian 5th ID is being airlifted to the battle and is expected shortly.
The Japanese supply situation is miserable at best and so Mutaguchi’s subordinates vainly call for a withdrawal, unimpressed by their commander’s orders to “fight with their teeth” if no bullets are available. Yanagida and Yamauchi are sacked for their insistence to withdraw while Sato, commander of the 31st ID plainly disobeys orders and begins to retreat. Mutaguchi claims Sato has lost the battle for him but the reality is clear: the Japanese have far reached the end of their supply lines. Sato’s withdrawal allows Slim to reopen the Kohima-Imphal road with two divisions and pump enough supplies into Kohima and Imphal to prepare for a counterattack.
The fresh British 2nd ID finally breaks the siege of Kohima after more bitter fighting but the Japanese forces are literally starved of supplies such as food and ammunition. The British have plenty of all supplies and even have the air capacity and complete air superiority to transport another division, the Indian 7th ID to Kohima. Meanwhile, a seesaw battle continues on the Imphal Plain where the Japanese make progress before being pushed back. The fighting is heavy but the Japanese are taking severe casualties from superior British tanks, artillery, and punishing strafing attacks.
The Japanese 31st ID completely surrounds Kohima instead of capturing the British supply junction at Dimapur, which is undefended and within striking distance. The 161st Indian Infantry Bde is quickly flown in to break the encirclement but is outnumbered and so camps outside Kohima. The Japanese 15th and 33rd IDs meanwhile block all the roads out of Imphal, which forces Slim to supply Imphal solely by air. Both sides take heavy casualties fighting on the Imphal Plain as Slim intends but the situation in both cities is desperate. Slim’s fortunes rise when the entire British 2nd and Indian 5th IDs arrive by air to Dimapur and Imphal respectively.
Mutaguchi advances against Imphal with the 33rd ID from the south and the 15th ID from the east. Although Slim fails to immediately recognize the Japanese main attack as such and withdraw to the Imphal Plain, the Japanese (barely) fail to destroy the Indian 17th and 20th IDs where they stand as planned. Slim saves his two divisions by sending the Indian 23rd ID to cover their withdrawal to defensive positions. Meanwhile, Slim is disturbed by the fact that the Japanese 31st ID – a full division, not a regiment – has cut the road connecting Kohima and Imphal.
Slim counterattacks from his strong positions against the disheartened and weakened Japanese forces. The Indian 20th and 23rd IDs strike and pursue the Japanese 15th ID while the Indian 17th ID strikes and pursues the Japanese 33rd ID. The Indian 7th ID must merely chase the Japanese 31st ID back across the Chindwin River. The Japanese suffer the majority of their casualties during this rout from malnutrition and disease.
British 14. Army
(Slim)
Landmarks
Pheru River
161st
Naga Hills
Subordinates
2nd
7th
Dimapur
31st Division
31st Division
Indian XXXIII Corps (Stopford)
50th Indian Parachute Brigade – Browning
161st Indian Infantry Brigade – Warren
254th Indian Tank Brigade – Scoones
2nd Infantry Division – Grover
5th Indian Infantry Division – Briggs
7th Indian Infantry Division - Messervy
17th Indian Infantry Division – Cowan
20th Indian Infantry Division – Gracey
23rd Indian Infantry Division - Roberts
Kohima
50th para
31st
31st
British 14. Army Japanese 15. Army
Infantry division Infantry division
Infantry brigade
Tank brigade
33rd
254th
7th
161st
254th
15th Division – Yamauchi
31st Division – Sato
33rd Division – Yanagida
Indian IV Corps (Scoones)
5th
23rd
Imphal
Yu River
Imphal Plain
Chindwin River
15th
20th
Irang River
Tengnoupal Ridge
Manipur River
17th
Kabaw Valley
Tuivai River
33rd
Japanese 15. Army
(Renya Mutaguchi)
100,000
British 14. Army
(William Slim)
155,000
Symbol guide
Subordinates
Japanese 15. Army
(Mutaguchi)

6. Kohima-Imphal, 1944 Casualties & Aftermath
Japanese 15. Army:
British 14. Army:
53,000 or
53%
17,500 or
11%
The Japanese 15. Army was virtually destroyed. By failing to capture British supplies during an anticipated rout, the Japanese could no longer effectively supply themselves, especially during the monsoon season. Nonetheless, the Japanese 15. Army was rebuilt and formed a strong barrier to British advances beyond the Chindwin Valley and deep into Burma in As the British prepare to invade Malaya in July 1945, the Japanese surrender following the atomic bombings of two of its cities.
By Jonathan Webb, 2009

7. The Art of Battle: Animated Battle Maps
By Jonathan Webb, 2009