According to this answer science questions that refer to real life science are legal on this site as long as they relate directly to the sci-fi universe they are asked in.

So my question is why did the Empire under the Emperor and Vader crumble? They where very similar to Nazi Germany, which only survived because it could plunder the neighboring countries. But the Empire was basically the only force in the entire universe (yes there are the Hutts and what not).

Judging from the footage of Curoscant in the end of The Return of The Jedi it seems society had not crumbled (at least not in the capitol).

Did the rest of the Empire not look so well? Or did the Empire have some secret to making socialism work? Or did the Empire have more neighbors than I seem to realize?