Top Cambridge public intellectual argues for economic, political reform if the dire events at the opening of the 20th century are not to be repeated. A new world crisis is already looming. By the middle of Obama's second term, or of the first term of his, presumably Republican, successor, America's legacy to the 21st century will be decided. Will it be a century of climatic disaster and war? The roots of the present crisis lie in an unbalanced globalization which has failed to match economic with political integration. False models of nationhood, markets, and empires have hindered the development of global governance. These illusions in turn are part of the ideology of American exceptionalism. If human civilization is to survive the 21st century, that ideology will have to give way to a more realistic acceptance of supranational authorities, and especially of an enhanced IMF and WTO. The banking collapse of 2007-8 calls for a revived understanding of the interdependence of politics and economics. The self-images of nations have lost touch with the realities that determine our lives: it is the world order that now gives us our identity and alone can secure our collective future.