“In its statement Unesco asserted that ‘cultural property’ was part of the ‘cultural heritage of all mankind’ and deserved special protection. But the framers of that doctrine with its universalist stance would hardly recognize cultural property in its current guise. The concept is now being narrowly applied to assert possession, not to affirm value. It is used to stake claims on objects in museums, to prevent them from being displayed and to control the international trade of antiquities.”