Unchecked, hostile action in space could produce debris, orbiting the earth at nine times the speed of a bullet, so prevalent as to put at risk all sophisticated spacecraft including satellites. This could place manned and unmanned space flight at unacceptable risk of mission failure due to catastrophic collision with debris. Not only would investment in, and insurance for, advanced spacecraft and launch engineering be extinguished. Of much greater importance, mankind’s access to space for exploration and pursuit of knowledge would be closed off – for young and old alike, for schoolchildren, scientists and aspiring astronauts, in America and around the world, possibly for a very long time. A more toxic legacy for US security policy would be hard to conceive.