Depends what the dominating ideology of the rest of the world is.
What do you base this on?Poland - democracy, with some nationalism directed towards Germans obviously.
Russia - if communism is overthrown by the Germans, they probably don't return to it but evolve into some dictatorship with democratic facade and Putin-like strong leader.
In the case that Nazi Germany manages to successfully occupy Poland and/or Russia for a significant amount of time - enough to enforce their rule there but not enough to reduce them to a blithering wreck - what ideology would the countries revert to once freed?
Poland: Either a democracy with a strong nationalist-authoritarian element or Communism, depending on how much the Germans were able to against the Soviets.
It could be a pure democracy. It could be a relapse of authoritarianism. But why Communism? IOTL it failed to gain any support before being imposed by force - which would render half of the original question senseless.
But why Communism? IOTL it failed to gain any support before being imposed by force
which would render half of the original question senseless.