The Allied plan to invade 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 islands by the Japanese as bases to threaten the supply routes between the United States and Australia and to use them as starting points. With U.S. President Franklin D. Roosevelt's tacit consent, King also advocated the invasion of Guadalcanal. Because the United States supported Great Britain's proposal that priority be given to defeating Germany before Japan, the Pacific theater had to compete for personnel and resources with the European theater.