A country is the product of its race. Our race has invented practically everything (aeroplanes, motor cars, computers, television, telephones, light bulbs, refrigeration, space ships, etc., etc., etc.). Can anyone imagine the Africans inventing space ships? Race is about more than just skin colour.
We are the direct descendants of the most intelligent, inventive people possibly imaginable. For our race, race mixing will only reduce our race, and thereby our countries, to almost their level.