These letters potentially cast the standard history of the German bomb in a very different light, suggesting that Heisenberg and his colleagues found a silent way to make a moral decision, not that they were spared one.5
In the thirty years that remained to him, whenever Heisenberg was asked to explain the German “failure” to build a bomb, his answer was what he had written to Elisabeth in letters before, during, and just after the war—that he had stayed in Germany because it needed him, and he had been spared the difficult moral decision of whether to build a bomb by the impossible immensity of the task—exactly what you might expect to hear from a man who didn’t want to do it, and found a way to say no.
I for one tend to agree with the conclusion that Heisenberg could have initiated a German Manhattan project had he desired.