Some time ago, an American leftist told me that the Berlin Wall was necessary to keep the West out of East Berlin. he wasn't happy when I started laughing. I said that even to a 9 year old, it was clear the tank traps were set up to stop people fleeing to the West.
It's too bad the Westerners did not leave a section of the Wall standing. It would stop people from rewriting the truth about it.
East-side gallery is still standing.