In Rwanda and the Balkans, neighbors often killed neighbors. How did they turn on people they'd known all their lives? And in the Holocaust you had incidences of this, too — I'm thinking of Jan Gross' book, entitled "Neighbors," about a small village in Poland named Jedwabne where the Catholic half of the village killed the Jewish half simply because they were given permission to do so. You realize how thin this veneer of civilization is that we put up. We say we live as neighbors and in a community, but when something happens structurally that says now you have permission to persecute, to take from, to even kill people that you've lived with for years, the relative ease with which people can do that is incredible.