As the nuclear arms race exploded in the 1980s, a group of U.S. religious pacifists used radical nonviolence to intervene. Armed with hammers, they broke into military facilities to pound on missiles and pour blood on bombers, enacting the prophet Isaiah's vision: "Nations shall beat their swords into plowshares and their spears into pruning hooks." Calling themselves the Plowshares movement, these controversial activists received long prison sentences;...