The U.S.-China trade war is making headlines, but the most important aspect of the long-term economic competition with China isn’t soybeans or natural gas, it’s technology. The dual flashpoints of economic espionage and backdoor surveillance could precipitate the great uncoupling of the world’s two largest economies. Although American politicians have just started to pay attention, China has been engaged in a decadeslong, systematic, state-sponsored effort to steal U.S. technology. Beijing has relied heavily on stolen trade secrets and intellectual property to build its own indigenous manufacturing and technology base. Recent U.S. intelligence community estimates suggest that China employs 30,000 military cyber spies and 150,000 private sector cyber experts whose job is to steal foreign secrets and technology. China’s economy has thus grown substantially, often at the cost of American companies. China is estimated to be...