For half a century the US has sat at the center of the global economic system, and Western-style capitalism has dominated. Now, it's no secret that the center of gravity is shifting. The advanced economies that in 2000 consumed 75% of the world's output will, by 2050, consume just 32%. Meanwhile, the emerging economies of the world--Brazil, India, China, and others--will surge forward. As these fast-growing, low-income economies mature, will...