Bill Gates is betting on America's decline and putting his money on China's rise. Or so the Microsoft founder seemed to say last month at the World Economic Forum held in Davos, Switzerland. "I'm short the dollar," he said. "The ol' dollar is going down." At the same meeting, Gates linked his pessimism about the United States to optimism about China. He commended China as the great "change agent" in the world over the next 20 years and praised its "brand-new form of capitalism." Gates isn't the only titan talking down the dollar and linking it to America's decline. Warren...