Missle Defense Missile Defense- Historical Safeguard, the only previous operational U.S. missile defense system, was completed in 1975 and deactivated after only four months. read on View as Slide Show View Images Missile Defense, Current and Future The U.S. system to be deployed in Alaska and California by 2004 will launch interceptor missiles to destroy incoming warheads in their midcourse (post-boost) phase through physical impact. read on View as Slide Show View Images