ABSTRACT
The destruction of the cities of Hiroshima and Nagasaki in 1945 happened after millions of people had died at the hands of modern technology in two world wars. Yet it was immediately understood that nuclear weapons were out of the ordinary and Janus-faced. They had hastened the end of a war, and their very dreadfulness seemed to confer on them a special utility as instruments of deterrence. Fears of the greatest imaginable catastrophe could be exploited to discourage states from going to war or from pushing one another around.
