My father was part of an airborne combat team on the USS James Jackson -- going through the Panama Canal on August 8th -- when he heard about Hiroshima.
He said everybody on the ship was convinced they had just avoided certain death -- that had they made it to either Guam or the Phillipines staging areas for Operation Majestic -- they would have never seen home again.
But I still wonder about a world where -- had Hitler been a little more patient with his military plans and more trusting of his scientists -- atomic warfare would have become oh too imaginable.
I still feel sympathy and horror thinking about the children killed in the two atomic blasts. Man as a species came very very close to practical extinction. The British, Japanese and Soviets were much closer to building gun-type U-235 bombs then was realized since most of our efforts were to get implosion plutonium bombs workable before the Nazis.
The mind truly boggles had Operation Barberrosa been delayed and the Nazis been able to develop and marry atomic weapons and superior rocket-based delivery systems before or contemporaneously with our efforts.
Somehow there's alot of "God" in the timing and turning of events. It's the ONLY explanation I can come up with.
Hitler never really cared for his atomic program, but that is not what crippled it. The scientists who were working on it used data from an old test (if I recall correctly, it was for the macroscopic cross section of absorption of uranium), that led them to believe that a nuclear weapon would have to be much larger that what is true, and that the only way to construct a nuclear reactor that used natural uranium (to make plutonium) was by using deuterium as a moderator. The plutonium solution was the only realistic solution because there was no doubt that allied bombers would have annihilated any massive plant to enrich uranium. This made the German atomic program dependent on the acquisition of large quantities of deuterium in order to make nuclear reactors to create plutonium. If they would have acquired the deuterium and started testing reactors, they probably would have found the error and started using other designs for their plutonium production reactors. But it would have been far too late. I can see no way that their delayed nuclear program could have produced enough bomb-making plutonium before the end of the war (especially with allied bombers annihilating every industrial facility). A good discussion on this is in the book The Making of the Atomic Bomb by Richard Rhodes (he got the Pulitzer Prize for this definitive history of the US atomic bomb program).
If that had happened, I doubt any of us would be here discussing it.