Former Senator Sam Nunn has proposed that the US, Russia, and other countries install self-destruct devices on nuclear missiles. That way, if a missile is launched by a renegade colonel or a group of terrorists (or whoever), the owning government could destroy the missile before it reached a foreign target. Nunn proposes that this would be cheaper and more effective than a missile defense system in protecting each nation from an accidental or unauthorized launch.--Stephen V Cole