The two countries, along with Taiwan, South Korea, and Southeast Asia, sit at the heart of the global economy. The iPhones, personal computers, and flat-screen televisions in electronic shops around the world; most of the mass-produced furniture and large amounts of the cheap clothing that fill shopping centers in the United States, Europe, and the United Kingdom; a vast array of industrial goods that consumers are scarcely aware of, from wires and valves to machine parts and the like—all of them, one way or another, are sourced through the supply chains anchored by Asia’s two giants. With so much at stake, how could they possibly come to blows?