With Chinese President Hu Jintao's visit to Washington, there's a lot of talk about the rise of China as an economic and military power. But the Chinese may have only a small window in time to assert global dominance -- and Chinese leaders have to know it. China is, perhaps, twenty years from the start of a demographic implosion, one that will cause enormous internal strains, economically and socially. Could awareness of the hard demographic realities that lie ahead for China drive the Chinese to advance their interests militarily, if need be, before China is hampered by an aging population?...