Obviously I disagree, Larry. And by your logic, 90% of all museum holdings should be returned to their country of manufacture. That would empty the Hermitage in no time! And, BTW, the Greeks today have nothing in common with the ancient ones and the marbles are not all that big of an issue in Greece itself. It is political grandstanding. As only the Greeks can do. If it has been years since you, or anyone has seen the Marbles, please re-visit the British Museum and see them in their beautiful dedicated gallery.
And, even further off topic, the Ottoman conquest of the decrepit Byzantine Empire is another topic I would gladly discuss.
However, as this topic is about Nazi looted artwork, I find it interesting that artwork created during the Nazi regime is banned from returning to Germany. There is a continual effort to erase it from the German heritage. A big mistake, in my opinion. It would be equally tragic if the current Russian government tried to erase it's Soviet & revolutionary heritage. Fortunately, I do not see that happening too much. Despite the name changes, history still recalls the sieges of Leningrad and Stalingrad for instance.
And, as an addendum, Russia holds quite a stash of art looted [booty] from Germany. I see exchanges take place every now & then, but the Amber Room, is most likely, never to be seen [original] again. The re-creation is flawless and we should be happy with that.