A contributing factor was Franklin D. Roosevelt's desire to keep U.S. troops active in the European theatre during 1943 and his attraction to the idea of eliminating Italy from the war.[29] It was hoped that an invasion might knock Italy out of the conflict,[30] or at least increase the pressure on it and weaken it.[31][32] The elimination of Italy would enable Allied naval forces, principally the Royal Navy, to dominate the Mediterranean Sea, securing the lines of communications with Egypt, the Far East, the Middle East and India.[32][33] Italian divisions on occupation and coastal defence duties in the Balkans and France would be withdrawn to defend Italy, while the Germans would have to transfer troops from the Eastern Front to defend Italy and the entire southern coast of France, thus aiding the Soviets.[34][35]