Arab families called it "al Mantiqa Haram." Jewish residents knew it as "shetach hefker." In both languages it meant the same thing: "the Forbidden Area." Soldiers on both sides that monitored the steep fault line dubbed it "Barbed Wire Alley." To folks on either side of the border, it was the same thing: A dangerous no-man's land separating warring nations and feuding cultures. It was in this no man's land that United Nation's soldiers organized a search party to rescue a pair of dentures that had fallen out of a monastery window overlooking the dividing line. It was on this street that an attempt to build an outhouse nearly sparked a deadly clash between Israeli and Jordanian soldiers stationed yards apart. The barbed wire came down in 1967. But it was soon supplanted by ever more daunting cultural, emotional and political barriers separating Arab and Jew.For nearly two decades, coils of barbed wire ran right down the middle of Assaell Street marking the fissure...