Directed energy weapons represent a potential revolution in military capabilities for tomorrow's warfighters, as well as a threat to the U.S. High-powered lasers have the potential to be formidable weapons, both lethal and non-lethal. In recent years, the U.S. has made several advances in high-energy laser technology, producing a megawatt-class laser, with several other countries not far behind. Combining lasers with space-based relay mirrors could offer the capability of transmitting a ground-based laser toward any point on the earth, an orbiting satellite, or a ballistic missile in flight. By the year 2035, several nations will likely have developed this capability, which will significantly affect U.S. national security. This paper examines the threat of laser/relay mirror systems and recommends actions the U.S. should take to protect itself from a high-powered laser attack, as well as deterring hostile nations from employing such a system.