somewhat protected anchorage, and the physical barriers to the east of the cape – for instance the mountain ranges and thick jungle – meant that mounting a counterattack would be beyond the capabilities of the Japanese for weeks, if not months, which would allow the US forces to consolidate after landing and give them enough time to establish a strong perimeter. Preparations for the landings Bougainville lay within the Southwest Pacific Area, so operations were nominally under the command of General Douglas MacArthur, whose headquarters were in Brisbane, Australia. Although MacArthur had to approve all major moves, he gave planning and operational control to Admiral William F. Halsey, Commander U.S. Third Fleet, headquartered at Nouméa on New Caledonia. In mid-October, Halsey set 1 November as the date for the invasion of Bougainville. By early October, it was clear to the Japanese that the Allies were planning a follow-up offensive to the Allied capture of the New Georgias, although the target was uncertain. The commander of the Japanese Combined Fleet, Admiral Mineichi Koga, flying his flag aboard the battleship Musashi from Truk Lagoon, sent all of his carrier aircraft to Rabaul. These planes would combine with the land-based air force already there and bomb Allied bases and supply routes as part of a plan the Japanese called Operation RO. In the event, this plan achieved very little besides further attrition to the Japanese air arm as the Japanese aircraft suffered heavy losses, which later prevented the Japanese aircraft from intervening against the US landings in the Gilbert and Marshall Islands. To confuse the Japanese as to the Allies' real target, two other invasions were carried out. The Treasury Islands, just southwest of the Shortlands, were occupied 27 October by the 8th Brigade Group, 3rd New Zealand Division under the command of Brigadier Robert Row, and a temporary landing was effected on Choiseul, one of the major islands in the Solomons chain. Unlike on Guadalcanal and the New Georgias, Allied planners were unable to gain valuable intelligence from coastwatchers or small Australian Army detachments as the Japanese had driven them off the island long before plans for Operation Cherry Blossom began. Forces allocated Rear Admiral Theodore Wilkinson, Commander Third Fleet Amphibious Forces, was assigned by Halsey to direct the landings at Cape Torokina from aboard his flagship, the attack transport George Clymer. The ships under Wilkinson's command would disembark the I Marine