Tokyo's decision to allow a nuclear-powered U.S. aircraft carrier to homeport in Japan could expedite U.S. Navy plans to retire its conventionally powered aircraft carriers and trim its carrier fleet to 11, according to Defense Department officials and analysts. U.S. lawmakers this spring rolled back a Defense Department effort to pare back the carrier fleet from 12 to 11 by arguing that the Kennedy -- one of two remaining conventionally powered U.S. aircraft carriers, and the ship set to be...