What happens -- psychologically -- when you build a wall

Thomson Reuters My friend Yaakov and I sat on a low concrete wall in the West Bank, peering into the darkness. When the twin beams of headlights appeared around a hill a few hundred yards away, we would squint. Then Yaakov, whose eyes are better than mine, would call out "Yellow!" or "Green!" If the call was "Yellow!" — meaning the license plate was yellow, belonging to an Israeli driver —we would stick our fingers out, waving them to attract the attention of the drivers. When the cars passe...