What did natural geography contribute to the Nazis' "Final Solution" and ultimate defeat?

The "Final Solution" is their final decision to exterminate all jews and diminish gypsie numbers as well. Not sure what the question means by "natural geography" means in the question though, it could mean how did the surrounding allied countries help Germany to do such a horrible thing or maybe it literally has something to do with physical geography (doubt it though) help please, no complete answers, only has to be 1 paragraph.