The trouble with missile defense

Missile defense is a system designed to shoot down incoming nuclear missiles before they hit. But if a country can shoot down, say, 100 enemy missiles, the enemy has an incentive to fire 200 to overwhelm the defense, leading to an offensive and defensive arms race. So in their arms control treaty, the U.S. and Soviets banned most missile defenses, relying instead on deterrence— the threat of mutual assured destruction. The U.S. pulled out of that pact in 2002, saying it needed the ability to defend against a launch by a terrorist or a rogue state such as Iran or North Korea. Since then, it has deployed defense systems in South Korea and sold anti-ballistic Patriot missiles to more than a dozen countries. The danger with missile defense is that if a country believes it can reliably defend itself against retaliatory nukes, it loses the deterrence of conducting its own first strike. But so far, despite billions in expenditures, missile defense is more of a fantasy than a reality. Patriot missiles failed to knock down most missiles fired by enemies in the Saudi-Houthi conflict and the 1991 Gulf War. In fact, says arms control expert Jeffrey Lewis, there is no evidence that a Patriot “has ever intercepted a longrange ballistic missile in combat.”