Ground crew members work on a pod of a British Royal Airforce VC-10 modified to take air samples to check for radiation after landing at Kadena U.S. Air Force base in Kadena town on Japan's southern island of Okinawa May 29, 2009. South Korea and the United States raised the military alert level for the peninsula on Thursday after the communist North warned the truce ending the Korean War was dead and it was ready to attack. REUTERS/Yuriko Nakao (JAPAN MILITARY POLITICS)