Hello, I imagine two scenarios

First, when the invasion of Japan was planned there were three landing sites. These were to be first attacked with aircraft carrying A-bombs. The resulting deaths from radiation would have been far less than that from enemy fire. The air war would have had to be far longer, and there is the possibility that England may have fallen before we had become involved. Then a cross Atlantic invasion, or perhaps an alternate stop off, or invasion area, would have been necessary. In short all means necessary, including atomic warfare with B29s. The ground campaign would have cost more, and Europe would be devastated.

The second scenario would involve either a failed offensive or a realization of the slim possibility for success. We would still have a type of Cold War scenario between ourselves and Germany. I would imagine Japan still would have fallen, and Italy also. Conflict between Germany and USSR would still be highly likely at some point. I believe it is stated in "Mein Kampf" about the need for
"living room" to be acquired in the east. He had a pathological need to destroy other "lesser" humans (untermensch).

Overall I'm happy with the way it worked out and haven't had to serve, fight a world war, lived in peace, etc. Father was a WW2 vet so I guess I've appreciated these facts over the years.