During the First Gaza War Köln, July 30, 2006   In the parking lot of Köln Cathedral, I watched pro-Israeli demonstrators waving blue and white flags. The Landespolizei in brown trousers and tan shirts stood between them and the Palestinians with their green and black banners. The demonstrations were disrupted by the bells for the evening mass. I went into the dark sanctuary of the Cathedral to listen. The homily was shot through with the words Krieg and Frieden, delivered from the high pulpit.   Behind an iron grate, the largest reliquary in the West holds the crowned skulls of…