Steam was till the other day the devil which we dreaded. Every pot made by any human potter or brazier had a hole in its cover, to let off the enemy, lest he should lift pot and roof and carry the house away.
Why wilt thou be so sottish, such an enemy to thyself, as to prefer puddle-water, and that poisoned too and stolen, before pure living waters out of thy own well?
As they were during the Cold War, urban population centers remain the most likely targets of a nuclear attack. Now, however, an attack may come without warning from an unknown enemy, to achieve unclear motives.