During the final months of World War II, from February 13 to 15, 1945, Allied forces bombed the ancient, cathedral city of Dresden, in eastern Germany. The bombing was controversial because Dresden's contribution to the war effort was minimal compared with other German cities — though it was a key transport junction and used by German forces to defend the country against Soviet forces approaching from the east. Before the huge air raid, it had not suffered a major Allied attack. By February 15, however, it was a smouldering ruin — 2,400 tons of high explosives and 1,500 tons of...