The Danube River has been a trade waterway for centuries, but with the rise of international borders and the jealousies of national states, commerce and shipping has often been hampered for narrow reasons. In addition, natural features of the river, most notably the sanding of the delta, has often hampered international trade. For these reasons, diplomats over the decades have worked to internationalize the Danube River in an attempt to allow commerce to flow as smoothly as possible.