The atomic bomb made the prospect of future war unendurable. It has led us up those last few steps to the mountain pass and beyond there is a different country.
In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin and this is a knowledge which they cannot lose.
When you see something that is technically sweet, you go ahead and do it and you argue about what to do about it only after you have had your technical success. That is the way it was with the atomic bomb.