Definitely NO! They are not just ‘national treasures’ they are “humankind treasures”, which transcend changing national boundaries. Many of the countries from which these treasures came from, especially but not only third world counties, do not have the means and often the will to look after them properly or allow them to be studied. Some countries even actively destroy them for pseudo-religious reasons as being pagan. As an archaeologist who has visited many museums around the world I am shocked to see many ‘museums’ as little more than derelict warehouses.