Following America's withdrawal from the Anti-Ballistic Missile (ABM) Treaty, FRONTLINE examines the reason why: the Bush administration's determination to deploy an antimissile system. Supporters say national missile defense is essential to protecting America from a missile attack by rogue states. Critics argue that terrorist attacks like September 11 are a far greater threat than that posed by ballistic missiles. In "Missile Wars," FRONTLINE examines both sides of the missile defense debate. Through interviews with staunch proponents, skeptical scientists, and military and intelligence experts, the one-hour documentary investigates this multi-billion dollar--yet still unproven--weapons system, and explores how national missile defense fits into the nation's military strategy after 9/11.