U.S. starts first test of key defense against ICBM attack

VANDENBERG AIR FORCE BASE, Calif. (Reuters) - The U.S. military has begun the first missile defense test involving a simulated attack by an intercontinental ballistic missile, firing off an interceptor from Vandenberg Air Force Base in California, a Reuters witness at the base said. It could be several hours before the U.S. military discloses whether the Ground-based Midcourse Defense (GMD) interceptor struck its target. The test came as fears mount about North Korea's advancing program to develop an ICBM capability. (Reporting by Lucy Nicholson, writing by Phil Stewart; Editing by Cynthia Osterman)