Alternative history is sort of difficult because we don’t know what the capabilities of those powers would have been. In order for the Nazis to have won the war a lot of people on both sides would have needed to make quite radically different decisions.

However it doesn’t take much theorizing to suggest that Nazi Germany would have probably had nuclear weapons in that scenario (the Germans were moving in that direction towards the end of the war, but were never really able to make much progress because by that point they were losing badly and didn’t have the resources anymore).

I can’t see how Japan would have ended up with nuclear weapons though. So I suspect a certain amount of power imbalance would have existed.