Last October, the United States Bureau of Industry and Security issued a document that, underneath its 139 pages of dense bureaucratic jargon and minute technical detail, amounted to a declaration of economic war on China. The magnitude of the act was made all the more remarkable by the relative obscurity of its source. In recent years, semiconductor chips have become central to the bureau’s work. Despite the immense intricacy of their design, semiconductors are, in a sense, quite simple: tiny pieces of silicon carved with arrays of circuits. The chips are the lifeblood of the modern economy and the brains of every electronic device and system, including iPhones, toasters, data centers and credit cards. A new car might have more than a thousand chips, each one managing a different facet of the vehicle’s operation. Semiconductors are also the driving force behind the innovations poised to revolutionize life over the next century, like quantum computing and artificial intelligence. ...