Christ appeared alive on several occasions after the cataclysmic events of that first Easter.
It was quite a European war until 1917 when the Americans joined up. They don't have the same sense of the loss of innocence and the cataclysmic loss of life. A whole generation was wiped out.
The weapons were conceived and created by a small band of physicists and chemists they remain a cataclysmic threat to the whole of human society and the natural environment.
Failure is not a single cataclysmic event. You don't fail overnight. Instead failure is a few errors in judgement repeated every day.