28th June – 4th August 1943 – Dutch East Indies - Borneo – The Drive to Samarinda
After the Kamikaze attacks and the engagement, it took until the 11th of June to secure British Borneo, largely because of small pockets of Japanese troops that had to be destroyed one by one and the temporary disruption to the movement of supply convoys owing to the fear that they might come under attack from elements of the IJN surface force that had survived the fighting off Borneo. With Sarawak secured the Allied forces called a temporary halt to operations to regroup and reinforce before striking into the heart of Borneo, where their intelligence sources indicated a much harder battle ahead [1].
There were even suggestions in some quarters, notably in Washington that in the aftermath of the latest defeat inflicted on the IJN that the remaining Japanese troops on Borneo could be left to ‘wither on the vine’ cut off from support and resupply they could simply be worn down by a mixture of air attacks and starvation. These suggestions received short shrift from the Dutch government in exile and most of the military professionals who been forced to deal with the fanatical determination shown by so many Japanese troops. What amounted to a siege strategy would take many months to complete and leave the Allied forces exposed to Japanese counterattacks. However weak the IJN might seem in June 1943 and however beleaguered the defenders of Borneo were the deployment of Kamikaze tactics meant that they could still inflict disproportion damage on the Allied forces before they finally collapsed. There was also the matter of the fate of the civilian population that remained in the hands of the Japanese, a particular concern for the Dutch who expected to continue ruling over the territory when the war ended. This was a legitimate worry and horror stories about the Japanese treatment of the locals on both Java and Borneo could have filled several volumes. Simply leaving the civilians to suffer in a siege would inevitably create antipathy towards the Allies and the last thing they wanted was the guerrillas they had encouraged, again over Dutch objections, to turn on them. In light of all these arguments the second stage of Operation Gawain would go ahead, with a planned date of 26th June 1943 [2].
While the ground troops were regrouping there was no respite for the Allied air forces. Airfields in Sarawak and on Java were rapidly improved to be able to handle medium bombers and make them more resistance to bad weather. This allowed for air attack to be staged into southern Borneo and the Japanese faced attacks from almost every model of fighter bomber, light bomber, and medium bomber in the Allied arsenal in 1943. There have even been accounts of the experimental use of Napalm in Borneo, even though official records state that the first actual combat deployments of napalm were in Europe after D-Day. Even if the Japanese were spared the destruction associated with that incendiary, they were subjected to daily air attacks, interrupted only by those days when the weather prevented the bombers flying [3].
General Kawaguchi could do nothing to halt these attacks. He had a handful of aircraft available after the strikes on the landing forces and those surviving aircraft had been a priority for Allied fighter-bomber sweeps, with most destroyed on the ground, though a few achieved a more ‘honourable’ death, attacking bombers and their fighter escort even though they were hopelessly outnumbered. The determination of the remaining Japanese pilots allowed them to score some successes despite the odds, however by the time the ground troops were ready to advance once more the only aircraft in the skies over Borneo belonged to the Allies. Kawaguchi was thus completely dependent on the strength of his defensive fortifications to resist the renewed attacks, though whatever he might have told his subordinates he had little confidence in their ability to hold off a major offensive. His plan called for a layered defence, with his units progressively falling back and bleeding the Allied troops every step of the way. This was a sound strategy given his limited resources, but Kawaguchi faced a fundamental problem in that this sort of co-ordinated retreat went against the doctrine that had been drummed into his troops, retreat was seen as almost as dishonourable as surrender to some officers and all too often during the Allied advance Kawaguchi’s frontline troops failed to disengage according to the battleplan, leaving companies and even entire regiments cut off and overrun [4].
The battle opened on the 28th of June, delayed for two days by a series of small spoiling attacks mounted by the Japanese, which annoyed Kawaguchi as much as it did the Allies since it went against his orders to hold on the defensive. He had allowed his local commanders some latitude in responding to enemy action and several chose to respond to Allied patrols by attacking some of the jumping off points for the Allied offensive. The delay this caused was outweighed by the losses to the Japanese and the consumption of ammunition and supplies that were already stretched thin. The main axis of advance was to be a sweep through the west and into central Borneo, aiming for the Mahakam River and the city of Samarinda on the southern coast of the island, securing the port there to shorten the supply lines of the advancing troops. I Provisional Corps was in the more central position, now reinforced with elements of the 5th Indian Infantry Division, which had the distinction of having fought all three Axis powers after having served in North Africa in 1941. In due course 5th Indian took over completely from 7th Australian Division, which became a recurrent theme in the latter half of 1943 as Australian, New Zealand, and Canadian divisions in the Pacific theatre were increasingly withdrawn, either for refit or moved to the European theatre of operations. The British Empire forces in South East Asia took on an increasingly Anglo-Indian flavour, tying India to the Empire or strengthening the hand of the Nationalists depending on whether you were talking to politicians in Whitehall or New Delhi. Elements of 8th Indian Infantry would also join I Provisional Corps during the latter stages of the battle [5].
US I Corps would advance further to the west, mopping up the smaller coastal towns, again improving supply lines, and hopefully punching through the Japanese lines and making a swift advance towards Samarinda, taking advantage of I Provisional Corps pinning down the enemy to their east and cutting the lines of communications for the elements of the Japanese forces facing the Americans. These defending forces were primarily composed of a badly understrength 35th Infantry Brigade, operating in terrain that didn’t afford much in the way of high ground or other solid natural defensive positions they could exploit. I Corps would need all the advantages it could get as unlike I Provisional Corps it had not been given a high priority for reinforcements, something that caused a great deal of bitterness among those who served in I Corps during the Borneo campaign. This decision had been taken because those in Washington who had been incessantly lobbying for an assault on the Philippines were finally getting their way. It would take months to fully prepare for the assault, it was however already being given the highest priority for men and equipment in the Pacific, which in addition to creating in the ranks of the US forces did nothing to improve relations between the British and the Americans [6].
When the initial Allied attacks went in on the 28th they made steady if unspectacular progress as they dislodged the Japanese from their forward positions. This was assisted by the fact that in this initial phase of the battle most IJA units did follow Kawaguchi’s orders to fall back while slowing down the Allies and inflicting the maximum possible casualties. The Allies however had also learned to be cautious when dealing with Japanese soldiers and they increasingly relied on armour and artillery to break down the defences to conserve the infantry as well as using infiltration tactics to work around the flanks and rear of those defensive positions that could not be crushed by superior fire power. By July 7th the advance began to slow and become more ragged as they encountered the main line of Japanese resistance and Kawaguchi committed what reserves he had available. Jungle terrain made it harder for the supporting aircraft to spot targets on the ground and attack them while at the same time slowing the advance of the artillery units, meaning that the infantry was sometimes left with little choice but to directly assault positions that couldn’t be bypassed, and these assaults inevitably proved costly even as they succeeded in unhinging the Japanese defensive positions.
Common sense prevailed and a brief halt was called on the 12th of July to allow reserves and supplies to catch up before a series of smaller actions were launched to eliminate several strongpoints that still threatened the cohesion of the advance. Despite some anxiety that the halt would allow the Japanese to regroup when the attack resumed on the 17th of July it began to make rapid progress. The Japanese were running short on ammunition and supplies and some units began to break with Kawaguchi’s plan, fighting on to the point where they were bypassed and cut off. A general breakdown in communications made matters worse and soon the entire defence began to crumble, falling apart and becoming a series of local skirmishes where the Allied forces could inflict a defeat in detail on the Japanese forces. Things got considerably worse when a fresh front was opened in the east, where the British had finally gathered enough forces, courtesy of 8th Indian, to assault the defences along the coast that had been increasingly thinly held as Kawaguchi tried to hold off the assault in the west and south.
Kawaguchi’s troops had put up a stiff fight, but by the 20th of July they were running out of everything, including manpower, and they were unable to mount a prolonged defence of Samarinda when the first elements of I Corps reached the outskirts on the 22nd, with 5th Indian approaching from the north on the 24th. The city finally on the 30th of July, with the last shattered remnants of the IJA forces falling back, losing most of their remaining supplies in the process. With Samarinda taken and the Japanese reduced to a few isolated pockets in the east the island of Borneo was declared secure on the 4th of August. Coming at the height of the fighting in Normandy this achievement went almost unnoticed in the British and American media. It was also arguably a premature announcement as skirmishing continued until the end of October, when the last pockets of Japanese resistance were crushed, though rumours persisted of lost Japanese platoons hiding out in the jungle for years after the end of the war [7].
Whatever the truth of these rumours Kawaguchi was not among those who hid out in the jungle, nor did he see the need to atone with his life for his failure to do the impossible and hold Borneo. He surrendered to Indian troops on the 3rd of August just east of Samarinda. His post war memoirs were scathing about the performance of his superiors in Tokyo and contributed to him becoming something of an outcast in the circles of Japanese veterans [8].
A few scattered garrisons survived in the outlying islands of the DEI into early 1944, largely because British resources in South East Asia were now focused on targets to the north, with Thailand acting as the prelude to a drive into French Indochina, while the American prepared to land in the Philippines [9].
[1] Split this off from the rest of the DEI operation to reflect the delay between the naval battle and the renewed Allied advance.
[2] A microcosm of the arguments over invading Japan later.
[3] Napalm may or may not have been used in Borneo, I leave that argument up to alt-historians.
[4] All that zealous indoctrination is not helping when you need your troops to follow a decidedly more pragmatic plan.
[5] On the one hand the Australians are asserting their own interests, on the other they are potentially weakening their influence by reducing their involvement on the front lines.
[6] On of the problems of greater Allied success is that some people feel they can indulge in ‘normal’ politics, and they have their eyes on the post war world rather than winning current battles.
[7] There will indeed be the odd Japanese soldiers emerging from the wilderness even as late as the 1970’s, though the degree to which they still thought the war was still on is debatable.
[8] Not popular but alive at least.
[9] Detailed accounts of those battles still to come once the little matter of D-Day has been dealt with…
