It all seems a bit like an ugly fairy tale now—an allegory, set in the heady and hectic late 1960s and early ’70s, of good versus evil, order versus chaos, revolution by dynamite sticks and law enforcement by black-bag jobs. This was, in retrospect, a match made in heaven: The Weather Underground and the Federal Bureau of Investigation, up against each other and both failing miserably.

While “it might seem strange to compare them,” says Arthur M. Eckstein, professor of history at the University of Maryland, “they were two organized groups of confused, frightened, and very angry Americans who broke the law. .  .  . No one on either side really knew what they were doing.”