The Allies were greatly concerned about the Japanese airfield construction effort on Guadalcanal because, when completed, the aircraft operating from the airfield would be a significant threat to Allied operations between Australia, New Zealand, and the U.S. The two strategic victories for the Allies in the battles of the Coral Sea and Midway provided an opportunity to take the initiative and launch an offensive against the Japanese somewhere in the Pacific. An Allied plan to attack the southern Solomons was conceived by U.S. Admiral Ernest King, Commander in Chief, United States Fleet. He proposed the offensive to deny the use of the southern Solomon Islands by the Japanese as bases to threaten the supply routes between the U.S. and Australia, and to use them as starting points for a campaign. His goal was to neutralize or capture the major Japanese base at Rabaul while also supporting the Allied New Guinea campaign, with the eventual goal of opening the way for the U.S. to retake the Philippines. The Allied commander-in chief for Pacific forces, U.S. Admiral Chester Nimitz, created the South Pacific theater with U.S. Vice Admiral Robert L. Ghormley in command to direct the Allied offensive in the Solomons.