Why are we terrorizing children over an exceptionally remote possibility?

‘Cold War kids were hard to kill, under their desks in an air-raid drill,” asserts Billy Joel in his 1989 ballad “Leningrad.” It rhymes but is almost certainly not true: Children subject to a nuclear strike would not be particularly “hard to kill,” whether or not they hid under their desks.

While wrong about their efficacy, Joel’s depiction of Cold War school-safety practices reflects the received wisdom of the time. In 1952, for instance, the Federal Civil Defense Administration released Duck and Cover — a grainy black-and-white film instructing school-age children on the putative best practices to protect themselves in case …