During the next year, the Allies advanced up the Solomons and along the northern coast of New Guinea so that by the fall of 1943, they were approaching New Britain. At the same time, Allied air raids eliminated Rabaul as a significant threat to future operations. Even though there seemed no reason to capture Rabaul, General Douglas MacArthur, commander of the Southwest Pacific Area, intended to establish a presence on New Britain. An amphibious assault against the Japanese stronghold, which was defended by nearly 90,000 Japanese troops and naval personnel, was deemed too costly, but the western end of the island was defended by only 7,500 Japanese, who were cut off from reinforcements by a lack of roads, rugged terrain, and Allied air and naval superiority.
MacArthur planned a two-pronged attack. The 112th Cavalry Regiment would land at Arawe on the southwestern coast of New Britain to attract and pin down Japanese reserves, while the 1st Marine Division would land at Cape Gloucester on the northwestern coast, where the Japanese had two airstrips. From these airstrips and a patrol-torpedo (PT) boat base at Arawe, MacArthur would complete the isolation of Rabaul.
The New Britain landings began on 15 December 1943, when the 112th Cavalry Regiment landed at Arawe and established a strong perimeter against little resistance. On 26 December, two Japanese battalions launched a counterattack but were beaten back, and in mid-January 1944 the 112th Cavalry eliminated the last pockets of Japanese resistance.
The Cape Gloucester landing began on 26 December. The Marines easily overwhelmed local Japanese resistance, although Japanese bombers sank the U.S. destroyer Brownson. By 30 December, the Marines captured Cape Gloucester; however, to secure the lodgment they had to expand their perimeter to two fortified hills on the western side of Borgen Bay. In fierce fighting made more difficult by swamps and heavy rains, they seized Hill 660 on 14 January 1944, ending any Japanese threat to Cape Gloucester.
New Britain now became a backwater as Allied forces moved west along the New Guinea coast. The Americans were content to protect their lodgments rather than mount an advance against Rabaul. But the Australian 5th Division, which replaced the Americans at the end of 1944, launched minor offensives against the Japanese that lasted until the end of the war. Total Allied casualties in the New Britain campaign were more than 2,000 killed and wounded. The Japanese lost more than 20,000 dead. In retrospect, given the air superiority the Allies had acquired over Rabaul by November 1943 and the seizure of the Huon Peninsula on New Guinea in early 1944, the New Britain landings were of little influence in the course of the war.
John Kennedy Ohl
Miller, John Jr. Cartwheel: The Reduction of Rabaul. Washington, DC: Office of the Chief of Military History, 1959.; Morison, Samuel Eliot. History of United States Naval Operations in World War II. Vol. 5, The Struggle for Guadalcanal, August 1942–February 1943. Boston: Little, Brown, 1949.; Shaw, Henry I., Jr., and Douglas T. Kane. History of U.S. Marine Corps Operations in World War II. Vol. 2, Isolation of Rabaul. Washington, DC: Marine Corps Headquarters, 1963.