Operation Oboe IV was a military campaign conducted by Allied forces during World War II, specifically targeting the island of Borneo in 1945. The operation aimed to liberate the island from Japanese occupation and was part of a broader strategy to secure the region and disrupt Japanese supply lines. The operation commenced on July 1, 1945, with landings at Balikpapan. Allied troops faced fierce resistance from Japanese forces, but they ultimately succeeded in capturing key locations. The successful completion of Oboe IV contributed to the overall Allied efforts in the Pacific theater, paving the way for further advances against Japan.