Mutually assured detection

ON JULY 20th 1960, a missile popped out of an apparently empty Atlantic ocean. Its solid-fuel rocket fired just as it cleared the surface and it tore off into the sky. Hours later, a second missile followed. An officer on the ballistic-missile submarine USS George Washington sent a message to President Dwight Eisenhower: “POLARIS—FROM OUT OF THE DEEP TO TARGET. PERFECT.” America had just completed its first successful missile launch of an intercontinental ballistic missile (ICBM) from beneath the ocean. Less than two months later, Russia conducted a similar test in the White Sea, north of Archangel.