What can the successes and failures of the twentieth century teach us about an uncertain future in the twenty-first? Bill Emmott argues that the best way to think about the future is to look back at the past, at the forces that have shaped our world and at what they tell us about the things that really matter. Two questions ultimately rise above all others: Will America continue to lead the world and to protect its peace? And will we continue to accept capitalism or will it be challenged once again? 20:21 Vision provides the answers that matter for all our lives in the twenty-first century.