カートホイール作戦
In early 1943, Rabaul had been distant from the fighting. However, the Allied grand strategy in the South West Pacific Area—Operation Cartwheel—aimed to isolate Rabaul and reduce it by air raids. Japanese ground forces were already retreating in New Guinea and in the Solomon Islands, abandoning Guadalcanal, Kolombangara, New Georgia and Vella Lavella.