BRUSSELS - An immense art theft occured during World War II. The Nazis dragged art from occupied countries to Germany and set up ambitious collections. For Belgium, that story has not yet been told. How could paintings of Memling, Van der Weyden, Brueghel, Jordaens and Cranach so easily leave the country? The Nazis emptied homes, stole art, forced owners to sell and spent millions of Reichsmarks on the art market.