On 24 January 1942, the Japanese overwhelmed the Australian garrison of 1,500 men at Rabaul and soon began construction of a large naval support facility, protected by five airstrips and two air armies with more than 600 aircraft. Rabaul became the base of the Eighth Fleet, and from the port, the Japanese could defend the approaches to New Guinea and the Solomon Islands and strengthen the southern flank of the region covered by their Central Pacific base at Truk in the Caroline Islands.
General Douglas MacArthur, Allied supreme commander in the Southwest Pacific Area, made the reduction of Rabaul a major objective. However, the position's strength persuaded Allied leaders at the August 1943 Quadrant Conference in Quebec to cancel MacArthur's plans for a direct assault in favor of a strategy of circumvention. "Island-hopping" was replaced by "leapfrogging." Preparations began on 12 October 1943 with massive air attacks by the U.S. Fifth Army Air Force operating from New Guinea, followed on 5 November by carrier raids mounted by the Saratoga and Princeton. These U.S. attacks forced the troops stationed at the Japanese garrison into a network of tunnels and caves and effectively ended Rabaul's usefulness as a naval base. Under MacArthur's command, Operation cartwheel continued the strike on Rabaul from the air, and eventually, 29,000 Allied sorties dropped more than 20,500 tons of bombs on the base. At the same time, the Allies seized positions to the southeast on the island of Bougainville, at Cape Gloucester on the western end of New Britain, and to the north in the Admiralty and Saint Matthias Islands.
By March 1944, the Japanese had withdrawn their major naval and air units, first to Truk and later to Palau, but 100,000 military and civilian personnel remained at Rabaul. Cut off from air or sea resupply, the Japanese garrison there suffered increasing deprivation until its surrender in August 1945. John A. Hutcheson Jr.
Dull, Paul. A Battle History of the Imperial Japanese Navy, 1941–1945. Annapolis, MD: Naval Institute Press, 1978.; 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.
John A. Hutcheson Jr.