SDI: If you missed the news, which isn't hard given how poorly these things are covered, our "unproven" missile defense proved itself again last week, when a U.S. warship downed a simulated North Korean missile in flight.The test, conducted in Hawaiian waters by the Navy and the Department of Defense's Missile Defense Agency (MDA), was the 23rd firing by ships equipped with the Aegis ballistic missile defense system. It was the 19th success, including the shoot-down of a dead U.S. spy satellite last year. A short-range ballistic missile simulating a missile like North Korea's Nodongs or Scuds was fired from...