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Since the end of the Cold War, big strategic thinkers have been longing for an enemy worthy of their big strategic brains. Many have tried hard to turn China into one. In the late '90s, Andrew Marshall, the Pentagon's near-legendary chief of "net assessment" and the last of the Truman-era Cold Warriors, directed a study that called for a wholesale reallocation of military assets away from Europe and toward Asia. In the view of Pentagon planners, the new Fulda Gap—the region where Soviet troops were poised to invade Western Europe during the Cold War—would be the South China Sea, a key "chokepoint" that the Chinese might some day seek to control. The prominent realist scholar John Mearsheimer argued that if China continued "modernizing at a rapid pace," it "would surely pursue...