To the west , American and Australian forces Hostile_encounter under General Douglas MacArthur had moved up Motion through the Southwest Pacific , isolating Removing or overrunning Destroying many Japanese strong points as part of Operation Cartwheel .

In November 1943 , allied forces landed Self_motion on the west coast of Bougainville as part of the latter stages of Operation Cartwheel , and began Process_start building air bases to assist in the isolation and neutralization of Rabaul .