Without public debate, indeed with almost no public awareness of the problem, a big and awesome decision, once postponed, was soon to be made.
U.S. scientists believed that they could manufacture a hydrogen bomb, an atomic bomb summoning up the same sort of fierce energy that gives the sun its heat. All that was needed was a way of forcing performance of a well-known scientific fact: if hydrogen atoms are converted into helium atoms, massive amounts of energy are released. The H-bomb could be at least 1,000 times as powerful as the atomic bombs dropped on Japan, might well use the...