In the early hours of December 16, 1944, Adolf Hitler's army launched a massive surprise attack on Allied lines across the frozen, forested landscape of Belgium. Caught off-guard, the Americans fell back into defensive positions. For a few desperate days before Christmas, the outcome of the war in Europe hung in the balance.   Desperate battles to stem the German advance were fought at St.-Vith, Elsenborn Ridge, Houffalize, and Bastogne. As the Germans drove deeper into the Ardennes in an...