With the release of George Clooney’s Monuments Men movie and the recent find of thousands of pieces of priceless Nazi-stolen art in a Munich apartment, much attention is being paid to wartime looting of artworks. Of course, the spoils of war have always been a side benefit of battle— a perk of the business of destruction, if you will—but the Nazis took looting to an extreme and methodical level. Hitler, a failed and ungifted artist, thought he cared about art and viewed himself as the arbiter...