The South needs the North as a source of low-cost labor to compete with China and the developing world. The North needs the South for everything from feeding the people to dragging the country into the 21st century. Like the reunification of East and West Germany, both sides will eventually have an open border, common currency, and a fully integrated economy. Unlike Germany, integration will occur at a much slower pace, given how much poorer North Korea is compared to how poor East Germany was.