way up to Calais and the English Channel—conveniently justifying the permanent German retention of those Belgian and French territories that Germany had just conquered during World War I. As an alternative to the idea of natural borders, Toynbee proposes making free trade, partnership, and cooperation between various countries with interconnected economies considerably easier so that there would be less need for countries to expand even further—whether to their natural borders or otherwise. In addition, Toynbee advocated making national borders based more on the principle of national self-determination—as in, based on which country the people in a particular area or territory actually wanted to live in. See also Natural borders of France References Borders Main