For millennia, fear of the unknown has surrounded the battlefields of war. German Field Marshal Erwin Rommel wondered where the Allies would strike in northern France ahead of D-Day on June 6, 1944. General Robert E. Lee anxiously awaited the long overdue return of his cavalry commander J.E.B. Stuart for intelligence on Union troop strength and positioning before the Battle of Gettysburg. Perhaps in recent times, the Ardennes Forest — covering in part Belgium, Luxembourg, Germany and France — proved that these nightmares can turn into reality. They did on Dec. 16, 1944, when Nazi forces, in what is now...