World War II Borneo: Allied Oboe Campaigm (May-August 1945)

Figure 1.--Sabah was a British controlled kingdom or sultanate at th nothern point of Borneo. It was part of Beitish Malaya. It had an agricultural economy. Tobacco plantations were the first major British activity. To open ip the inerior, the British built a narow gage railway. It was and contunues to be the only rail transport system on Borneo. The 134 km line became known as the North Borneo Railway. Rubber and oil would make Sabah more valuable than ever imagined. The line was destroyed during the War. As a result, a high priority after taking back Borneo was to get the rail line running from Jesselton to Papar operatung again. Here is a scene at Kinarut, a station near the coast. The engines were not operting. So a jeep was substituted. It was operated by the Australian Army 2/14TH Transport Platoon, 2/156th Geberal Transport Compny. The Americam jeep was used for just about everything during World war II, but as far as we know this was the only use as a locomotive. Source: Australian War Memorial.

Finally the Allies with New Guinea secured and the major Philippines islands liberated, began to move gainst Japanese held areas in the southwestern Pacific. The Allies decided to move first against lightly-populated Borneo rather than the heavily populated islands at the heart of the Dutch East Indies. The initial plan was for the conquest of the entire Dutch East Indies (DEI), but the Japanese surrendered before the final stages of the campaign needed to be launched. Operation Montclair was the overall Allied plan desugned to destroy Japanese forces in the southwest Pacific and reoccupy the the southern Philippines, the Netherlands East Indies, and British North Borneo (including the Kingdoms of Sarawak and Brunei). The Philippines operations were conducted by American and Filipino forces. The actions to the southwest in British and Dutch colonial areas were named Operation Oboe with landing forces composed primarily of Australian infantry. While Oboe. Borneo became the primary focus of the campaign primarily because of the oil resources--the primary reason the Japanese had invaded in 1942. By 1945 because of the Allied submarine campaign and subsequent naval operations, no oil was getting through to the Home Islands. The Allies saw, hoever, the oil as important to help fuel their operations. It should be rembered that it was believed that the War would extend into 1946. Very few people (including Vice Presudent Trumab knew about th Manhttan Project and this include all but a small number of military planners. The Oboe Borneo campaign was largely conductd by Australian infantry, but the United States provided vital air and naval support. It would prove to be the final important Allied campaign in the Southwest Pacific Area. The campaign was essentially a series of amphibious landings (May 1 - July 21, 1945). The Oboe landing force was the Australian I Corps commanded by Lieutenant General Leslie Morshead. Allied naval and air forces supported the landings. The primary naval force was the U.S. 7th Fleet commanded by Admiral Thomas Kinkaid. Air support was provided by the Australian First Tactical Air Force and the U.S. Thirteenth Air Force. There were opposed by two Japanese forces. The Imperial Japanese Navy and Army forces in southern and eastern Borneo were commanded by Vice-Admiral Michiaki Kamada. The Thirty-Seventh Army led by Lieutenant-General Baba Masao resisted in the north. Borneo is a huge island with only priitive transport and communications infrastructure. And the Japanese had only limited logistical capability even before the Allies invasion. Thus the Japanese resistance was not coordinated. Oboe 1 was the first action of the Borneo campaign. It was an assault on the small island of Tarakan off the northeast coast of Borneo (May 1). The goal here was to secure an air strip for the subsequent Oboe operations. The Australians heavily outnumbered the Japanese garrison. It was not, howevr, an easy fight. The Australians suffered narly a thousand casualties. Most of the 2,200 garrison Japanese fought to the death, but some 250 did surrender--more than was the case in most campaigns. The photograph on the previous page was taken on Tarakan. An Oboe 6 party was inserted into Kimanis Bay, British North Borneo (May 29). This was followed with simultaneous assaults on the island of Labuan and the coast of Brunei, in the north west of Borneo (June 10). This was followed by assaults on Japanese positions around Weston on the north-eastern part of Brunei Bay (June 17). Oboe 3 was the effort to retakle Brunei and Sabah in northern Borneo. The Australians landed at Brunei Bay (June 10) which was followed up by subseunt labdings in he area. This was the most important oil producing area of Borneo and was the area most heavily defended by the Japanese. The towns were in Autralian hands after some heavy engagements (July), but there were sporadic incidentsin rural reas until the Japanese surrender.The image here shows the Northern Borneo Railway which the Australians were putting back into operation with an American jeep (figure 1). Oboe 3 is commpnly called the Battle of North Borneo and led to retaking both Brunei anf Sabah. The Japanese retreated into the jungle and the Australians did not agressively persue them to limit casualties. Sporadic fighting continued until theJpanese surrender (August 15). Oboe 2 to seize Balikpapan in southeastern Borneo was launched (July 1). It would prove to be the last major Allied amphibious assault of World War II occurred at Balikpapan (July 1). Tt was also the the last campaigns launched by Australian forces. Oboe 4 and 5 were never acarried out. Oboe 4 was to had targeted Surabaya or Batavia (Jakarta). Oboe 5 targeted the eastern DEI. The Borneo Oboe campaign was not popular in Australia. Most of the fighting was conducted by Australian infantry and the casualties suffered by them. And the criticism continued after the War. It was described as 'pointless'. Some historians agree. One respected historian writes, "Any rational strategic judgment would have left them to their own devices screened by token allied forces until their nation's defeat enforced their surrender." [Hastings, p. 368.] Of course at the time, no one knew that the Americans with the atomic bomb were about to force a Japanese surrender. Other authors point out that there were some tangiblebl benefits. Seizing Borneo increased the isolation of the substantial Japanese forces on the main DEI islands. Important oil producing areas were secured. And Allied POWs being held in terrible conditions and in danger of execution were saved.


Hastings, M. Nemesis: The Battle for Japan, 1944-45 (Harper Press: London, 2007).


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Created: 8:19 PM 8/8/2017
Last updated: 8:19 PM 8/8/2017