‘Star Wars’ missile defense is back, but not how it should be

Space-based missile tracking sensors, high-energy particle beams that zap nuclear warheads and President Donald Trump’s call for a new “Space Force” branch of the US military. For those who remember President Ronald Reagan’s Strategic Defense Initiative (SDI) of almost four decades ago, it sounds like déjà vu all over again. Reagan pitched building an ambitious anti-missile system in 1983 […]