"The 21st century will not be dominated by America or China, Brazil or India." The 21st century, argues Parag Khanna at Foreign Policy, will be the century of the city.

"Gone," explains Khanna, "are the days of Mao when peasant uprisings could collectively capture the nation." Today "more than half the world lives in cities"--a percentage still on the upswing. World capitals like London, New York, and Paris drive globalization, even as new cities are "created ... virtually from scratch ... from the factory towns in China's Guangdong province to the artificial 'knowledge cities' rising in the Arabian desert." And they are only going to get larger.

As a result, he argues, the 21st century will be a sort of return to the medieval era, when "cities such as Cairo and Hangzhou were the centers of global gravity, expanding their influence confidently outward in a borderless world." Medieval Europe will also feel nearer than ever:

This new world of cities won't obey the same rules as the old compact of nations; they will write their own opportunistic codes of conduct, animated by the need for efficiency, connectivity, and security above all else. ... Alliances of these agile cities are already forming, reminiscent of that trading and military powerhouse of the late Middle Ages, the Hanseatic League along the Baltic Sea.
His vision nearly descends into Dark Knight territory at points, as he compares cities to cancer, and focuses on the rise of crime, terrorism, and private security forces. In this new world, he suggests, "cities--not so-called failed states like Afghanistan and Somalia--are the true daily test of whether we can build a better future or are heading toward a dystopian nightmare."