The U.S. military successfully shot down a mock intercontinental ballistic missile for the first time Tuesday in a crucial test of its missile defense shield amid escalating tensions with North Korea.A ground-based interceptor was launched from Vandenberg Air Force Base in California in the test to shoot down a mock-up of an ICBM from Kwajalein Atoll in the Marshall Islands, the Missile Defense Agency said."The intercept of a complex, threat-representative ICBM target is an incredible accomplishment for the GMD (ground-based midcourse defense) system and a critical milestone for this progra…READ FULL ARTICLE