There would be no way to stop. The German economy was really messed up by the Nazis. They essentially had no exports because they were producing mainly materiel for the war and were under an embargo anyway.
That means they had no way to get money besides literally taking it from conquered countries. The problem is, you can only loot once. This created a vicious cycle where they became more isolated and needed to conquer even more.
Honestly, before nukes existed, the Nazis could have been defeated by an embargo. But it would have cost more lives. Invading Germany saved lives and the nukes saved even more lives in Japan.