I’ve always been impressed by the solemn, magnificent simplicity of the Changing of the Guard at the Tomb of the Unknowns at Arlington National Cemetery. The carefully choreographed event is a moving tribute to soldiers whose names—and sacrifice—are “known but to God.” Equally moving are the private moments of steady pacing when the crowds are gone: back and forth, hour after hour, day by day, in even the worst weather.

In September 2003, Hurricane Isabel was bearing down on Washington, DC, and the guards were told they could seek shelter during the worst of the storm. Surprising almost no one, the…