Four F-22A stealth fighters have flown to the U.S. Air Force's Kadena Air Base in Okinawa from Guam, base officers said Friday. The fighters arrived at Kadena on Thursday from Andersen Air Force Base on Guam. The officers did not say why the fighters have flown to Kadena, but said they will leave Okinawa within a week. The F-22A was developed jointly by Lockheed Martin Corp. and Boeing Co. It is a single-seat, twin-engine fighter designed to be difficult to detect by radar. The U.S. Air Force temporarily deployed F-22 fighters to Kadena base on three occasions between 2007 and...