"the US could have relentlessly nuked the Soviets after Japan immediately post WW2" They didn't have enough nukes neither they had delivery methods. Japan is a

"the US could have relentlessly nuked the Soviets after Japan immediately post WW2" They didn't have enough nukes neither they had delivery methods. Japan is a tiny island, but most of Soviet industry were located on the Volga rived and beyond on the Ural mountains. That's very far from sea and very far from any territory USA reliably controls. I don't think they had strategic bombers that could reliably take dozens of targets off. And contemporary bombs were small-powered devices that wouldn't destroy everything. They will only make Soviets very angry and the rest of the world hating and fearing them. Add to this that Europe would hardly be friendly if they did that, seeing themself as a next target. Will hardly help them deliver nukes.