How the U.S. watches the N. Korean threat

In this Wednesday, April 10, 2013 photo, U.S. Air Force F-16 fighter jets fly during a military exercise at the Osan U.S. Air Base in Osan. South Korea. The names of U.S.-South Korean war games staged over the years don't sound all that threatening: Team Spirit, Ulchi Focus Lens, Key Resolve ... Foal Eagle. But whatever they're called, the annual show of force is guaranteed to get a rise out of Pyongyang. (AP Photo/Ahn Young-joon)Special radar has been deployed to track a missile if it is launched.