The Empire of Japan had largely achieved its objectives in the Pacific region in the spring of 1942, with almost the entire area between Burma and the Bismarck Archipelago under Japanese control.

Until mid-September 1943, the fighting focused on the eastern part of New Guinea, while a decision was made on 22 September 1943 to land in West New Britain.

Operation Dexterity was to be conducted in three separate phases: After the successful conclusion of these three phases the Allies landed at Talasea to try to cut off the thousands of retreating Japanese troops under the command of Major General Iwao Matsuda who successfully escaped to defensive lines in central New Britain after the small force of Japanese defenders delayed the Marines from quickly advancing to the withdrawal route.

General Imamura therefore foresaw an attack on New Britain, at the latest after the Allies had occupied New Ireland, which was expected in February or March 1944.

The 8th Area Army relied exclusively on barge and submarine traffic from Rabaul to New Guinea, because of Allied air superiority.

The Japanese headquarters was established in an existing concrete bunker at the foot of Talawe Mountain, which was surrounded by dense, tropical vegetation.

Smaller bunkers and shelters for machine gun positions were sited at possible Allied landing beaches five miles southeast of Cape Gloucester.

Two days after the decision to proceed with the operation was taken by the Allied commanders, the US 6th Army's Alamo Scouts began to deploy in the area of Cape Gloucester.