The proliferation of short- and long-range missiles did not end, as some hoped, with the Cold War. As Iraq and North Korea have illustrated, modern missile technology can lend first-class military power to poor and developing nations. Consequently, debate has reopened in the U.S. on the viability of a national missile defense system based on a constellation of space-based lasers. There is little debate whether or not lasers can track and destroy missiles. U.S. military programs dating back to the seventies have successfully proven the feasibility of a light-speed defense. And even if a space-based defense is never mounted, work is underway with the aim of deploying both airborne and ground-based laser defenses. Like the debate about lasers in space, these other programs confront issues revolving around cost, scale, and energy sources. One thing seems certain: as long as the proliferation missiles continues so will research into laser-based defense.