World War II was the most devastating conflict in human history, but the tragedy did not end on the battlefields. During the war, Germany -- and, later, the Allies -- plundered Europe's historic treasures. Between 1939 and 1945, German armed forces roamed from Dunkirk to Stalingrad, looting gold, silver, currency, paintings and other works of art, coins, religious artifacts, and millions of books and other documents. The value of these items, many...