I'd say it's certainly up to the French to decide. As for my opinion: imagine if China, Russia, or some other nation invaded the US and built something of significance. During this period, they not only killed many of us but humiliated us as a nation. Created a "brand", so to speak, of a weak and inconsequential America.
I would hope we would take to demolishing any such monument to our disgrace the minute we drove them out.
wow... really? preserve that crap? tear down that wall. it’s history that can be left to the history books. you don’t leave monuments up to invaders, who were then beaten back and repelled. that wall is a monument, and monuments are for winners, not losers who killed 6 million Jews and Gypsies.