The Berlin Wall: 13 August 1961—9 November 1989, by Frederick Taylor; Bloomsbury, 2006, $35. IN THE SUMMER OF 2006 friends of mine, a middle-aged couple from Bautzen, a thousand-year-old city in the Upper Lusatian region of Saxony between Dresden and the Polish border, were cycling around Holland. In Rotterdam on a guided tour they were told that they were in the “new city”. In all innocence they asked what had happened to the “old city”. Their guide took some pleasure in explaining to them in grim detail exactly what had happened to Rotterdam on the night of May 14, 1940.…