Between 1951 and 1992, the United States set off nearly a thousand nuclear bombs
at the Nevada Test Site, an empty and awesome stretch of desert whose cratered surface resembles the face of the moon. Throughout the site's 1,350 square miles are the remains of houses, fortified bunkers, and parking garages, structures built to see how much damage bombs of various sizes could do. Visible amid the detritus of bomb blasts are simple examples of plutonium's power—telltale shards of the radioactive green glass that is created at ground zero during a nuclear explosion.
As I toured the desert recently with some of the men who specialize in the arcane art of detonating nuclear weapons, it occurred to me that the Americans who mastered plutonium had plenty in common with the smiths and chemists who first mastered iron, bronze, copper, and steel. Every great empire in history, from the Greeks to the British, has been founded on an ability to manipulate metal into new and ever more lethal forms.