The thesis of this book is that when fossil-fuel reserves deplete in a few years, the global human population of Earth will drop to about 500 million people or less — a small fraction of the current six billion. The future is one of global ethnic war and the end of the modern industrialized world. The book examines a "minimal regret" population strategy that shows promise as a long-term-sustainable, environmentally sound basis for world population. This population consists of a single industrialized nation of five million people and a hunter-gatherer population of five million.