- 129 - Pacific War - The Japanese Defeat at Imphal and Kohima , May 7-14, 1944

Last time we spoke about the remarkable success of Operation Reckless and Persecution.  Colonel Oliver Newman led the drive towards Hollandia's airfields, encountering scattered opposition and discovering large undefended Japanese supply dumps. General MacArthur was forced to postpone future plans until May 21st. Meanwhile, Allied submarine interceptions disrupted IJN troop movements, and Task Force 58's airstrikes neutralized Truk. Within Burma, General Stilwell's offensive faced challenges from Japanese resistance and heavy monsoon rains. Despite setbacks, the 22nd Division aimed to capture Inkangahtawng while Chinese forces engaged the enemy along various fronts. Chindits continued Operation Thursday, facing logistical hurdles and Japanese attacks. Colonel Kinnison's Marauders encountered strong resistance near Tingkrukawng, while Colonel Hunter's force successfully surprised the Japanese at Myitkyina. 

This episode is the Japanese Defeat at Imphal and Kohima

Welcome to the Pacific War Podcast Week by Week, I am your dutiful host Craig Watson. But, before we start I want to also remind you this podcast is only made possible through the efforts of Kings and Generals over at Youtube. Perhaps you want to learn more about world war two? Kings and Generals have an assortment of episodes on world war two and much more  so go give them a look over on Youtube. So please subscribe to Kings and Generals over at Youtube and to continue helping us produce this content please check out www.patreon.com/kingsandgenerals. If you are still hungry for some more history related content, over on my channel, the Pacific War Channel you can find a few videos all the way from the Opium Wars of the 1800’s until the end of the Pacific War in 1945. 

We are jumping right back into the heat of General Mutaguchi’s insane Operation U-Go. Poor General Yamauchi after suffering a devastating defeat at Nungshigum, was now facing allied tanks he simply had no answer for. Yamauchi ordered his men to dig in around Sendgmai and Kanglatongbi, basically so they would at least be hung around the Kohima-Imphal road. The allies answer to this was 6000 sorties, dropping 1000 bombs in the sector. It was a tremendous amount of damage, but the Japanese did benefit from bunkers. Yamauchi’s 15th Division due north of Imphal were now being contained successfully, allowing General Briggs and Roberts to initiate their own counter offensives by the end of April. Simultaneously the 33rd Division was struggling to advance upon Bishenpur and the Shenam Saddle; over at Kohima, General Sato’s 31st Division was reluctantly falling onto the defensive as the looming threat of a full British-Indian counteroffensive was dawning upon them.

Imphal was still facing a grave threat from the Japanese along the Tiddim Road. Mutaguchi was personally directing the 33rd Divisions actions around Bishenpur at this time. Mutaguchi planned a three-pronged attack, one prong along the Tiddim Road, another down south from the Silchar Track by the 215th Regiment and a lastly from the north by the 214th Regiment. For the assault the 33rd Division received reinforcements in the form of the 14th Tank Regiment; the 2nd Battalion, 18th Heavy Field Artillery Regiment; and the 1st Anti-Tank Battalion from the Yamamoto Detachment. In late May they would also be receiving the 151st regiment and the 14th Tank regiment, amongst other units. This of course meant other units like the Yamamoto Detachment were being deprived of men, thus they in turn would be reinforced. The Yamamoto Detachment received the 2nd battalion, 51st regiment who were previously engaged with the Chindits at Indaw. They would arrive at Kampang after the fall of Crete West. Now in preparation for Mutaguchis renewed offensive the IJA would be tossing aircraft against the Gun Box in Bsihenpur. The Japanese Army Air Force made four air raids on the Gun Box position in Bishenpur in the first ten days of May. There was good reason for this, for at Gun Box the 32nd Indian Brigade had concentrated its artillery support. This included four 3.7in. howitzers, eight 25-pdrs, six 6-pdrs and three A/A guns. From here the guns were able to support the infantry’s actions both on and around the Silchar Track, as well as the villages on the Tiddim Road such as Potsangbam. The Japanese heavy field artillery was at Khoirentak. The 215th regiment meanwhile performed some preliminary attacks against the positions at Ngarangial. Attacks began in early May against positions between Wireless Hill and Ngarangial, with two battalions attacking from the north and one from the south. The enemy, in strong positions, withstood a series of attacks which continued until the middle of May. While Mutaguchi waited for reinforcements to arrive so he could renew his southern offensive, Generals Yamamoto and Gracey were slugging it out for control over Crete West.

The extremely exhausted 3rd battalion, 213 Regiment finally made a break through against the Lynch Pimple on the 8th,  forcing the 80th Brigade to evacuate Crete West two days later. On the night of the 10th, Yamamoto launched his first attacks against Scraggy Hill, which was extensively shelled, followed by a massive infantry assault: in classic style, wave upon wave of Japanese soldiers crashed on Scraggy, overwhelming its forward defenses. A point was finally reached in the night when the British battalion commander on Scraggy felt that the hill would fall unless supporting artillery fire was directed on his own positions. This was called in and the Japanese advance finally halted on the morning of 11th. But parts of Scraggy were now under the control of Yamamoto Force, which dug in. General Scoones reacted by relieving the exhausted 20th Division with the fresher 23rd Division of General Roberts. The new arrivals were shocked to see the conditions on the forward positions of the Shenam Saddle. Scraggy stood out. The Japanese were on part of the hill, while the rest of it was under British control. Trenches and bunkers covered the feature; in places, mere meters separated the two sides’ front trenches. Bits of body parts of soldiers lay everywhere and a terrible stench covered the hillside.

Now Cowan was planning a counter to Mutaguchis incoming offensive. He planned for an anvil and hammer maneuver; the hammer would be the 63rd Indian Brigade recently relieved from Sekmai in the first week of May by the 89th Indian Brigade. They would push down from Bishenpur towards Potsangbam, Ningthoukhong and even further south while the 48th Brigade established a roadblock on the Tiddim Road around Torbung, deep behind enemy lines. Cowan hoped to crush the 33rd Division along the road between his hammer and anvil while also cutting off the incoming Japanese reinforcements. Thus Brigadier Ronald Cameron’s 48th Brigade stealthily advanced south along the eastern shore of Lake Loktak, crossed the Manipur River at Shuganu. It was a long grueling march. Simultaneously, Brigadier Guy Burton’s 63rd Brigade advanced south against Potsangbam on the 10th. In their frustrated push southwards on the Tiddim Road, Burton’s men had to deal first with the determined Japanese defense of Potsangbam. Burton took over on the 9th from Mackenzie’s 32nd Indian Brigade, which had gained a foothold in the village the day before and was now to give its full attention to the Silchar Track. The 63rd Indian Brigade put in a first attack on Potsangbam on 10th. This involved two Gurkha battalions, each supported by a troop of tanks from the 3rd Carabiniers. The area they targeted was the main part of the village east of the Tiddim Road. The initial full frontal attacks failed to make much progress.

Burton then changed tack against the Japanese, who had withdrawn to their main defenses south of the Potsangbam turel. He called for a heavy artillery bombardment from the same direction as before in the northern half of Potsangbam to make it appear that he was repeating the previous line of attack. Except this time he instructed one of his battalions to pass secretly behind the other and make for the area to the immediate east of the road. The move worked and the road through the village and its immediate vicinity were captured by the 15th. The Tiddim Road through Potsangbam was now open, although the Japanese still held on in parts of the village. But it had all taken much longer than expected. While the anvil at Torbung was about to be put in place, the hammer had only inched forward. After a long and difficult march, the brigade arrived near Torbung in mid-May. The roadblock was set up on 17th where three nullahs crossed the road near Milestone 33. To the east were several low-lying hills where brigade headquarters was established, centered on one called Point 3404. The sluggish Khuga River flowed between the hills and the road. In the Torbung sector, the Americas surprised Lt. Colonel Matsuki of the 33rd Supply Regiment, who was given the mission of reopening the line of communications using whatever troops were available in the immediate area. A composite company from the 33rd Supply Regiment, which had been deployed in the Mountainous area west of Churachandpur, held Hill 4358 against several enemy attacks. On the night of 17th, approximately 100 men of the 33rd Supply Regiment were gathered from rear elements to make the first attack on the roadblock. The attacking group was mounted on trucks and the leaders miscalculating the location of the enemy position drove squarely up to the roadblock and the entire attacking unit was virtually annihilated.

Mutaguchi reacted furiously to this by unleashing artillery fire upon Point 3404 and the roadblock from the surrounding hills. Cameron’s guns responded with retaliatory fire. Simultaneously Mutaguchi tossed his 1st battalion, 67th regiment against the Torbung roadblock, but Cameron’s men held on inflicting tremendous casualties against the Japanese. Meanwhile Burton unleashed an attack against the hills immediately west of the road in the hopes of cutting off the supply line of the 214th and 215th Regiments. The 63rd rigade set off on 18th; the next day it had captured the villages of Tokpa Khul and Kha Aimol, and near them Three Pimple Hill and OP Hill respectively. This directly threatened the 33rd Divisions HQ at Laimanai. Mutaguchi reacted by abandoning the assaults from the west and south, and redirected the 215th Regiment to deal with Burton’s 63rd division. All three of Sasahara’s battalions were thrown into the counterattack, the first of which went in on the 20th. Another major assault was made two days later; both were driven off. The Japanese lost over 110 men. But they persisted and put in further attacks over the next week, frustrating any further movement southwards for the 63rd Indian Brigade. The Japanese failed to clear Burton’s position, their relentless attacks would completely pin down the 63rd Brigade, thus preventing any further movement southwards. 

Now at this point the 32nd Brigade had managed to recapture Wireless Hill, prompting Mutaguchi to abandon Potsangbam by the 24th. The 4th Independent Engineer Regiment and 2nd battalion, 213th Regiment fell back to Ningthoukhong. Mutaguchi then tossed another battalion to help out in the attack against Burton’s 63rd division. Without further support of the hammer, Cameron’s anvil force had to repel a coordinated tank-infantry attack on the 21st and again on the 23rd. The 2nd Battalion, 154th Infantry Regiment and a composite company from the 14th Tank Regiment attacked on the 21st and again on the 23rd but were not only unsuccessful in dislodging the enemy, but also suffered extremely heavy losses. Two tanks were destroyed during these attacks. Though the anvil held firm, Burton’s failed attempts to continue the push south would ultimately force Cameron to abandon the roadblock and head back. 

On May 24th, the 48th Brigade was fighting through Bishenpur heading up the road finally linking up with the other brigade around Potsangbam. Thus the Torbung roadblock was an enormous success for Cowan, his men had inflicted 500 casualties and disrupted Mutaguchi’s plan completely. Now Mutaguchi chose to go ahead with only part of his original plan, the attack from the north that would be carried out by Colonel Sakuma Takayoshi’s 214th regiment. To oversee the Bishenpur offensive,  Major-General Tanaka Nobuo was appointed in command of the 33rd Division. Leaving Bungte on the night of the 19th, Sakuma’s 1st battalion advanced south to attack Bishenpur from the north, while the 2nd battalion moved north from Wainen and attacked Hill 2926. Yet as they tried to storm Point 2926, they were beaten off by a platoon of the 7/10th Baluchs. Failing to take the peak, they captured the southern part of the feature and parts of the adjacent Maibam village. The 1st battalion proceeded with their assault against Bishenpur targeting the area at the northern end of the village, near the junction between the Tiddim Road and the Silchar Track. This is also the area where the Gun Box was. Once they had managed to infiltrate the road junction area, however, the Japanese were repeatedly counter-attacked in the next few days, British tanks firing on their positions at close range. Without any anti-tank guns and the British tanks firing on their positions at close range, they were ultimately wiped out. 

Back over with the 2nd Battalion, they had successfully captured Maibam village and Hill 2926, very close to Cowan’s headquarters, so the British would have to direct several reinforcements to lay siege on these enemy positions. Early on the 26th, Sakuma directed a composite company to launch a last charge on Bishenpur from the north, but this attack would also end in failure. Cowan then directed the brigade-strength Woodforce to evict the Japanese from Hill 2926.  Woodforce consisted of the 50th Indian Parachute Brigade’s HQ, commanded by Brigadier Woods and was a composite force of tanks, artillery, sappers and infantry. Taking over the front on the 26th, Woodforce mounted robust counter-attacks over the next two days, finally overcoming all opposition and recapturing the hill and Maibam by the 29th. With most of the 33rd Division fighting to reopen the Tiddim road at Torbung, Sakuma’s 214th Regiment was left to extricate itself as best it could. But the fall of the Torbung roadblock on the 24th also allowed Mutaguchi’s reinforcements to finally reinforce Ningthoukong in preparation for an attack on Potsangbam. 

At this point, the balance of power had shifted very definitely to the allies. Sakuma’s early success at Hill 2926 was the closest any Japanese would get to Imphal from the south. Meanwhile General Yamamoto’s attacks against the Shenam Saddle resumed on the 20th, with his men rushing the crest of Scraggy in waves throwing gelignite bombs and grenades, but ultimately getting pushed back each time. Meanwhile the 2nd battalion, 51st regiment and 1st battalion, 60th regiment began an attack against Gibraltar, a very steep hill along the saddle. Their initial attacks were repelled easily, but on the night of the 23rd they managed to gain a foothold on Gibraltar's crest and this in effect cut off the 37th Indian brigade at Malta and Scraggy. With the Fourteenth Army units on Malta and Scraggy cut off, the fate of the entire Shenam Saddle now hung in the balance, but the very next day the hill was recovered by a counter-attack led by the 5/6th Rajputana Rifles and 3/10th Gurkha Rifles. Gibraltar would be the farthest the Japanese would be able to advance on the Shenam Saddle and the closest they came to breaking through; and from then on, a stalemate developed with neither side making any important moves. After the Japanese had been evicted from Gibraltar on the 24th, they did not follow up with another major attempt to push through the Shenam Saddle for a fortnight. But there was never really a quiet moment on these heights. Sniper fire was ever-present, as was the booming of artillery guns. The situation was the worst on Scraggy, where both sides continued to maintain their respective positions. The British and Indian units here would be fired on from Nippon Hill, besides being subjected to rifle fire, mortaring and grenade attacks from Scraggy itself.

To the north, General Brigg’s resumed his counteroffensive against Molvom, tossing his 9th Brigade into a series of attacks against the Japanese held Hump. The infantry put in several attacks against the Hump, suffering increasing casualties. The men of the 3/14th Punjabis attacked Hump at least half a dozen times that month. Despite it all, the Japanese were still found in their bunkers at the end of May. Sited on the reverse slopes of Hump, their bunkers were difficult to target by guns firing from the other side. Even when they were hit, they were so solidly built that they suffered little damage. The defenders of Hump would wait until the 3/14th Punjabis neared the crest; they would then let loose a barrage of machine-gun fire and grenade attacks. Attack after attack had to be called off in the face of such furious resistance. Though heavy artillery and mortar fire and repeated air strikes were called in on it, the tenacious Japanese defenders would successfully repel all British-Indian attacks throughout early May. 

On the other side, realizing the vital need for artillery support, General Yamauchi decided to bring to the front the field guns that had been left east of the Chindwin River. He also was reinforced with the 2nd Battalion, 67th Regiment, which would seize Lamu on May 10th, securing the rear of the 15th Division. On the 15th, thanks to the timely arrival of the 89th and 123rd Brigades, Briggs was able to renew his assaults in front of Sekmai with greater intensity, finally clearing Kanglatongbi and the hills to the immediate east six days later. 

Colonel Matsumura responded by creating new defensive positions around Modbung. As the month came to a close, Briggs decided to concentrate both his division’s brigades on the Imphal–Kohima Road. The 9th Indian Brigade was to be brought on to the road, swapping places with the 89th Indian Brigade, which would move to the Iril River Valley. The opening of the Imphal–Kohima Road was a far greater priority than clearing the Mapao– Molvom Range. The Japanese defenders of the latter would be left where they had hung on for weeks. In any case, the opening of the road was likely to encourage them much more to leave than any direct attacks on their positions. 

On May 15th Yamauchi was relieved of his command. Yamauchi had really drawn the short end of the straw. As he admitted at the time, his men simply had no answer to the British tanks. His men had thrown themselves into the jungle as lightly as possible in order to strike Imphal quickly, so they did not have effective anti-tank weapons. Ymauchi’s division was always the Japanese weak spot, but they valiantly had refused to lift their roadblock at Kanglatongbi. As a last desperate throw, Yamauchi had ordered the use of poison gas. Yamauchi was also a man who understood how strong the allies were, especially America. Unlike the xenophobic and ignorant Tojo and Mutaguchi, Yamauchi had spent time in the USA and this led him to be quite pessimistic. Regardless, without anti-tank weapons it was quite hopeless. Yamauchi was carried from the battlefield on a litter and would later die in a hospital in Maymyo.

Back over at Kohima, Generals Stopford and Grover were continuing their counteroffensive. Brigadiers 4th Brigade were occupying Oaks Hill when on May 1st, they began to descend during  The Royal Scots stopped their advance and reoccupied Oaks Hill, the brigade artillery back in Jotsoma was on standby to pound any Japanese positions the Norfolks, who were pressing on down the ridge, encountered. The Japanese, alert now to the dangerous presence of enemy troops above them, moved up against Oaks Hill and fought hard to expel the Royal Scots during that first night, with no success. The morning that followed a night of screaming, fear-inducing attacks found the jungle undergrowth littered with Japanese bodies. It was usual practice for the Japanese to take away their dead and wounded, but on this occasion there were too few Japanese survivors for the task. As the Royal Scots repelled numerous enemy counterattacks, the Norfolks were continuing their descent towards the GPT ridge. On May 4th, the Norfolks found themselves in a good position to assault the crests of the ridge. They stormed up catching the Japanese by surprise, managing to seize numerous bunkers.

At the same time, the 161st Brigade was able to seize the area southeast of Two Tree Hill, but the Japanese had a complex bunker system there preventing them from linking Jotsoma with Pulebadze. The bunker complex on GPT Ridge was much more substantial than the British had expected, with literally dozens of small, carefully sited bunkers littering the entire area with interlocking arcs of fire, while the entire position was also covered by Japanese machine guns further to the east on the Aradura Spur. No sooner would one be discovered and attacked, than another would open up against the attackers from somewhere else. Until the entirety of GPT Ridge was cleared, Goschen's brigade could not enjoy the shortcut through to Jotsoma via Two Tree Hill; the road to Imphal remained in Japanese hands and their machine guns continued to spray fire on 6th Brigade's exposed right flank. Within the center the 6th Brigade was attacking Kuki Piquet and FSD Hill. While the attack against Kuki Piquet was not seeing much progress, they did gain a toehold atop FSD Hill. Further north, the 5th Brigade were able to bypass the 138th regiments position on Merema Ridge. They managed to secure a small part of Naga Village by the end of the day. Being close in proximity to General Sato’s HQ, the response from the Japanese was a series of fierce counterattacks. THe 33rd battalion, 14th regiment stormed the Cameron Highlanders who did not have time to consolidate their success by digging in, and heavy Japanese mortar fire at daylight forced the Jocks back to the western edge of the hill. Here Hawkins had them dig to secure the ground that had been seized and the Worcesters, who had protected the flanks of the night advance, were called up to help build a defensive position able to resist counterattack. The rain was by now constant. Everyone was drenched to the skin. The next morning the Japanese Air Force made one of their occasional forays into the deep valley that flowed out of the Kohima Ridge westward, but to limited effect. 

Meanwhile Brigadier Frederick Loftus-Tottenham’s newly arrived 33rd Brigade was in the process of reinforcing the exhausted 6th Brigade at Kohima Ridge, with preparations being made for a renewed general counteroffensive. Meanwhile, over on Pulebadze on the 6th, B Company of the Norfolks, commanded by Captain Jack Randle, was ordered to seize the remaining part of the bunker position at the bottom of GPT Ridge, while the 4/lst Gurkhas of , assisting the breakthrough in the center against Kohima Ridge and Jail Hill, were to attack the lower, western slopes of GPT Ridge. In these attacks the Norfolks were to seize the remaining Japanese bunkers but at high cost, in which Capt. Randle was awarded the posthumous VC. 

The Norfolks remained in the positions they had seized and, after a night of heavy rain, a further attempt to attack the remaining Japanese positions was made at first light on the morning of 7 May by the 4/lst Gurkhas and the Royal Scots. It was important that this operation was successful, as at 10.30am an attempt was to be made by the 1st Queen's - part of 33rd Indian Brigade, who had arrived at Kohima exhausted and malaria-ridden from Arakan the day before - on Jail Hill. If the machine-gun nests on GPT Ridge could be wiped out before the Queen's attacked they would enjoy a much higher chance of success. The only result of this failed assault would be the death of Brigadier Goschen, shot by snipers. 

The Queen's, aware that 4th Brigade had not managed to secure GPT Ridge, nevertheless went in against Jail Hill as planned and were slaughtered. In retrospect the attack was premature, but Stopford continued to demand speed to remove the Japanese stranglehold on Kohima in order to relieve beleaguered Imphal. There was a belief in some higher quarters - held in particular by those whose only experience of the terrain came from reading a map in the comfort of a headquarters tent in the rear - that 2nd Division's offensive lacked pace. These accusations were preposterous to the hard-pressed men on the ground. It was impossible for commanders and staff officers in the rear who could not see the ground to understand how a small piece of jungle-topped hillside could absorb the best part of a brigade; how a small group of well-sited bunkers could hold up an advance until every single one - together with every single occupant - had been systematically destroyed; how only medium artillery could penetrate the roof of a Japanese trench; how only direct and short-range sniping by Lee/Grant tanks was guaranteed to defeat a Japanese bunker; how the desperate terrain, incessant rain and humidity led even the fittest men to tire quickly and what an extraordinarily determined opponent they faced. With few exceptions, the Japanese gave in only when they were dead. Every conscious man who could lift a weapon fought until he collapsed.  Due to these defeats, the British-Indian morale plummeted, even though Sato’s men were also facing a serious supply problem that was further weakening them with each passing day. 

Nevertheless, the Japanese continued a brave defense under heavy artillery, mortar and aerial bombardment. Sato's defensive technique, while it was not going to enable him to break through Kohima by dint of offensive action, was designed to do the next best thing: to draw the enemy onto defences of great complexity and depth and to break them there, both physically and morally. In so doing his troops had to withstand the sort of conditions few other soldiers in history could have survived. They did so, and very nearly succeeded in persuading Stopford that battering through Kohima was an impossible task. Between the 4th and the 'Black 7th', for instance, the 38 3.7in. mountain guns dug in around Jotsoma fired over 3,000 rounds, the 48 25-pdrs fired over 7,000 rounds and the big 5.5in. guns of the medium artillery fired more than 1,500 shells at the Japanese positions, not to mention the almost continuous salvoes from the 3in. mortars of the infantry battalions and the constant strafing and bombing by Hurricanes and Vengeance dive-bombers.

For the next few days, General Stopford’s brigades were slowly reducing the Japanese defenses. British progress, though slow, remained sure, even though it seemed to the troops on the ground as if this battle would go on for ever. 4th Brigade cleared GPT Ridge on 11 May, by which time further costly attacks by the British 6th and 33rd Indian Brigades had finally forced the Japanese to relinquish their hold on Pimple, FSD and Jail hills, the latter of which was captured by the Queen's and C Company, 4/lst Gurkha Rifles. The tide was slowly - and painfully - beginning to turn. On the days that followed, the positions seized on 11 and 12 May were carefully consolidated, the remaining Japanese being exterminated one by one, sniper by sniper and gun by gun. The Berkshires cleared FSD Hill on 12 May, discovering that the Japanese had honeycombed the hill with tunnels, creating an elaborate underground fortress that included a battalion headquarters, repair shop, ammunition storage dump and hospital. Those Japanese bunkers on the western edge of the ridge that remained out of reach of the British artillery could now be engaged directly and at pointblank range by the Lee/Grants, trundling up the road that divides DIS and Jail hills. They did so to the cheers of the British and Indian infantry, who found themselves hugging the ground as the 75mm smashed the enemy foxholes only metres from them, the ground shaking and the shockwave of the blast sucking out their breath and showering them with dirt and debris.

The capture of the southern part of Kohima Ridge a full 37 days after the arrival of Sato’s units would force the Japanese to retreat to a secondary defensive line north of Aradura. On the 15th, patrols of the 5th Brigade advanced down from Naga Hill, securing Treasury Hill before meeting up with the exhausted victors of Kohima Ridge who were advancing along the Imphal road. Yet that is all for the India front, as we now need to jump back over to check out what is going on with Operation Ichi-Go.

After the fall of Xuchang, General Uchiyama dispatched some units south to attack Luohe, while the bulk of his 12th Army advanced north to capture Luoyang and hopefully annihilate General Enbo’s 31st Army Group. On May 2nd, General Uchiyama dispatched the 110th Division against Dengfeng, the 62nd Division against Yuzhou and the bulk of his 37th Division, 3rd armored division and 4th cavalry Brigade against Jia and Ruzhou. On 2nd, the 4th Cavalry Brigade defeated the enemy force in the sector southwest of Yingchiaochen and, on the 4th, advanced to the sector northwest of Linju. The 3rd Armored Division routed the retreating enemy heading west and, on the 4th, mopped up the enemy in the vicinity of Linju. Also on the 4th, the 37th Division arrived at Linju. On the same day, the 7th Independent Mixed Brigade occupied Hsiangcheng. on the 3rd the 62nd defeated the 29th Army at Yuzhou while the 3rd Armored Division and the 4th Cavalry Brigade pursued the retreating Chinese towards Ruzhou. On the 4th, Uchiyama’s main forces were able to capture Ruzhou and the 110th Division managed to dislodge the 13th Army’s position east of Dengfeng. After this Uchiyama’s main forces enveloped the area, annihilating the 13th and 29th Armies at Dengfeng while the 62nd and 110th Divisions made a frontal assault of the city. Alongside this the 7th Independent Mixed Brigade attacked the enemy near Likouzhen.

Yet before Uchiyama’s men could complete the envelopment, General Enbo’s men pulled out towards Tangjiezhen and Changshuixiang around midnight on the 5th. On the 7th, the 37th Division and 7th Brigade managed to envelop Tangjiezhen, and with air support inflicted heavy casualties on the outflanked defenders. Simultaneously, the 27th Division captured Luohe and Suipin. General Yokoyama had dispatched the 11th Independent Brigade to aid Uchiyamas men from the south, facing little resistance as they captured Queshan and Zhumadian before linking up with the 27th Division on the 11th. 

On the other side, General Jiang Dingwen’s 1st War Area Army was regrouping the bulk of its forces along the Luoyang-Yiyang line. General Okamura Ysuji ordered the 12th Army to advance upon Luoyang while Lt General Yoshimoto Teiichi’s 1st Army crossed the Yellow River to try and cut off the Chinese retreat at Xin’An and Xiashichiang. Having defeated the enemy in the sector southwest of Dengfeng, the 12th Army continued to keep the enemy in the Loyang area under strict observation while, at the same time, it ordered the 110th Division to pursue the enemy toward Iyang, the 62nd Division to pursue them toward Pingteng, the main force of the 3rd Armored Division toward Iyang and Hsinan and the 4th Cavalry Brigade to the western sector of Pingteng. Okamura dispatched his reserve 63rd Division led by Lt General Nozoe Masanori to try and break through at Sishuizhen so they could join the attack upon Luoyang. They were successful and in the process, defeated the 177th Division and managed to reach the northeastern sector of Luoyang by the 12th. With assistance from the 59th Brigade coming from the west, Nozoe captured Xin’an by the 14th. The 62nd Division and the 4th Cavalry Brigade captured Pingdengxiang on the 13th and part of the 110th Division captured Yiyang on the 14th. Most of the 110th Division, however, moved to Lungmenchieh below Luoyang. The 3rd Armored Division also reached the area southwest of Lungmenchieh at this point. The 37th Division, meanwhile, was directed to move towards Sunghsien. These actions effectively enveloped Luoyang as Uchiyama had his 110th Division advance through the Luohe River Valley; Yoshimoto’s men advance to Sanmenxia which would fall by the 18th. The 37th Division captured Song alongside the aidromes at Luoning and Lushi by the 20th. But the main effort would be made by the 63rd Division assisted by elements o the 110th Division who launched the assault against Luoyang, being defended by the 36th Army Group. On the 19th, the 63rd Division initiated its attack against enemy positions on the outskirts of Loyang, however, the enemy positions were so strong that the battle situation did not progress as planned. As a result of this the North China Area Army ordered the 12th Army to place the main force of the 3rd Armored Division and 4th Cavalry Brigade together with part of the 110th Division under the command of the 63rd Division commander. At the same time, the 63rd Division was ordered to defend the railway east of Mienchih. At 1pm on the 23rd, the 12th Army dispatched the 63rd Division to attack Luoyang Castle from the north and northeastern fronts of Luoyang to the northeastern corner of the castle while the 3rd Armored Division was to attack the castle from the western front toward the northwestern corner of the castle. The Army also directed the Cavalry Brigade to capture and destroy the enemy which it was expected would flee to the south at the line of the Lo Ho. On the 24th, the Army-called on the enemy in Luoyang to surrender but they refused. At 1pm, therefore, the Army opened its attack and, on the 25th, completely occupied the castle.

During this battle, Lieutenant-General Li Jiayu would heroically die covering the retreat of the remaining troops of his battered 36th Army Group. With the fall of Luoyang and the near destruction of the 1st War Area, Operation Kogo ended in a resounding success for the Japanese, thus securing the South Beijing-Hankou railway. The Japanese estimated over 32000 Chinese casualties and some 7800 troops captured. In turn, they claimed to have lost only 2000 casualties. Interestingly, Operation Kogo also saw the Henan peasants attack the Kuomintang forces in revenge for the Yellow River flood of 1938 and the Henan Famine of 1942. As told to us by General Jiang Dingwen "During the campaign, the unexpected phenomenon was that the people of the mountains in western Henan attacked our troops, taking guns, bullets, and explosives, and even high-powered mortars and radio equipment... They surrounded our troops and killed our officers. We heard this pretty often. The heads of the villages and baojia (village mutual-responsibility groups) just ran away. At the same time, they took away our stored grain, leaving their houses and fields empty, which meant that our officers and soldiers had no food for many days… Actually this is truly painful for me to say: in the end the damages we suffered from the attacks by the people were more serious than the losses from battles with the enemy." In the end, the peasants would be able to disarm over 50000 troops, picking their weapons to defend themselves from the Japanese, but also causing much damage to the Nationalist defense. For their role in this disaster, Generals Dingwen and Enbo would be relieved from their commands, with General Chen Cheng later taking over the 1st War Area in July to oversee its recovery. Meanwhile, the Japanese would continue to prepare for Operation Togo, the Hunan offensive. Yet to finish off this episode we also need to mention some progress in the future plans to invade Wakde.

Admiral King had requested support from the British Eastern Fleet. At this time the Eastern Fleet was organized into three forces for Operation Transom, the invasion of Japanese occupied Surabaya. Force 65 consisted of Battleships Queen Elizabeth, Valiant, Renown, the French battleship Richelieu, two cruisers and eight destroyers, under the direct command of Admiral Somerville; Force 66 consisted of aircraft carriers Illustrious, Saratoga, two cruisers and six destroyers, under the command of Rear-Admiral Clement Moody aboard Illustrious. Force 67 was the replenishment group and comprised six tankers, a water distilling ship and the cruisers London and Suffolk. Somerville commanded the entire fleet from Queen Elizabeth. The warships were drawn from six navies, the capital ships being accompanied by three American destroyers, four British cruisers and three destroyers, four Australian destroyers, a Dutch cruiser and destroyer and a New Zealand cruiser. The Australian light cruiser HMAS Adelaide also sailed from Fremantle in Western Australia to protect the tankers while they were at Exmouth Gulf; this allowed their two escorting cruisers to augment Force 66 during the attack. Two squadrons of Supermarine Spitfire fighters were transferred from No. 1 Wing RAAF at Darwin to Exmouth Gulf to protect the Eastern Fleet while it refueled and Australian and American maritime patrol aircraft were assigned to operate offshore. Each carrier had an air group made up of units from their parent navies. Illustrious embarked two squadrons equipped with 14 Vought F4U Corsair fighters each and two squadrons with nine Avengers. Saratoga's air group comprised a squadron with 26 Grumman F6F Hellcat fighters, a squadron with 24 Douglas SBD Dauntless dive bombers and a squadron operating 18 Avenger torpedo bombers, as well as a single Hellcat allocated to the Air Group Leader.

As for Surabaya, its defenses against air attack at the time of Operation Transom included a few anti-aircraft guns, whose crews were inadequately trained. Radar stations and a network of observer posts were also sited to detect minelaying aircraft. The Japanese forces stationed in the city included the Imperial Japanese Army's 28th Independent Mixed Brigade and the headquarters of the Imperial Japanese Navy's 2nd Southern Expeditionary Fleet under Vice-Admiral Mikawa Gunichi. Because of the distance to be covered from Ceylon and the Royal Navy's lack of experience in underway replenishment, the final plans for the operation involved the Eastern Fleet refueling at Exmouth Gulf in Western Australia before striking Surabaya. Force 67 was the first element of the Eastern Fleet to sail, departing on April 30th. Forces 65 and 66 sailed on May 6th. The Allied ships proceeded to Exmouth Gulf on a course that kept them at least 600 miles from Japanese airfields to avoid being detected or attacked. The carriers air wings practiced the attack they would conduct on Surabaya three times during the voyage. The warships arrived at Exmouth Gulf on 14 and 15th ofMay. The Eastern Fleet departed Exmouth Gulf on the afternoon of the 15th and proceeded north. It arrived at the flying off point at 6:30 am local time on the 17th without being detected by the Japanese. One British and seven American submarines also took up positions near Surabaya, the southern entrance to the Strait of Malacca and the Bali, Lombok and Sunda Straits to support the Eastern Fleet. The submarines were positioned to rescue Allied aircrew that were forced down, attack ships that tried to escape from Surabaya and intercept any Japanese warships that attempted to attack the Allied fleet.

Operation Transom opened up with 76 aircraft launched from Illustrious and Saratoga. The aircraft launched by the carriers were organized into two strike forces. Force A was made up of nine Avengers from Illustrious, twelve Dauntless dive bombers and an escort of eight Corsairs. Force A's Avengers were to bomb the Braat Engineering Works and the Dauntlesses the oil refinery. Force B was to attack shipping and dock facilities in Surabaya's port. It comprised twenty-one Avengers and six Dauntlesses escorted by eight Corsairs and twelve Hellcats. The commander of Saratoga's air group, Commander Joseph C. Clifton, led both carriers' air wings during the attack. All of the aircraft were launched and formed up with the rest of their force by 7:20 am. Two British Avengers crashed during takeoff, their crews being rescued.

The attack on Surabaya commenced at 8:30 am. The Japanese had not detected the aircraft as they approached, and were taken by surprise. The two forces made a well-synchronized attack, Force A approaching Wonokromo from the south and Force B attacking the port from the north. No Japanese fighter aircraft were encountered, and the anti-aircraft guns were largely ineffective. One of Saratoga's Avengers was shot down, and both members of its crew became prisoners of war. The two forces claimed to have damaged 10 ships, demolished the Wonokromo oil refinery and the Braat Engineering Works, destroyed 16 aircraft and leveled several buildings. Saratoga and her three escorting American destroyers detached from the Eastern Fleet shortly before sunset on the 18th, and proceeded to Fremantle. The remainder of the Eastern Fleet reached Exmouth Gulf the next morning, and sailed for Ceylon before sunset after refueling again. Adelaide and one of the Australian destroyers that had been attached to the Eastern Fleet left Exmouth Gulf bound for Fremantle after the tanker group departed on 19 May. The Eastern Fleet arrived back at Ceylon on the 27th. Saratoga reached Bremerton, Washington, on June 10th and after a refit re-joined the Pacific Fleet in September 1944. Though the Japanese would not really divert any forces from western New Guinea in response to the raid and despite the fact that the Japanese claim that not much damage had been inflicted on their shipping or shore facilities, with only one vessel confirmed sunk, Operation Transom would provide Somerville’s Eastern Fleet important experience of carrier strike operations and exposure to superior American carrier tactics. 

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The Allies were gradually countering Operation U-Go as the intense battles at Kohima Ridge and Pulebadze saw British-Indian forces slowly gaining ground amid heavy casualties. Meanwhile, Operation Ichi-Go saw major Japanese successes in China. Lastly Operation Transom saw British-Dutch-American successful carrier strikes against Surabaya, yielding experience despite limited damage.