South Koreans watch the Nimitz-class USS George Washington leaving for joint military exercises at the Busan port in Busan, south of Seoul, South Korea, Sunday, July 25, 2010. The massive nuclear-powered U.S. supercarrier began maneuvers Sunday with ally South Korea in a potent show of force that North Korea has threatened could lead to "sacred war." (AP Photo/ Lee Jin-man)

Photo by: Lee Jin-man

South Koreans watch the Nimitz-class USS George Washington leaving for joint military exercises at the Busan port in Busan, south of Seoul, South Korea, Sunday, July 25, 2010. The massive nuclear-powered U.S. supercarrier began maneuvers Sunday with ally South Korea in a potent show of force that North Korea has threatened could lead to "sacred war." (AP Photo/ Lee Jin-man)