A grassy plain in Nevada’s Humboldt County is where the contest between the U.S. and China for mastery of the global economy could be won or lost. Called Thacker Pass, the empty patch of land, 230 miles from Reno, looks decidedly uninteresting, home to little more than scrubby bushes. But it’s what lies beneath that places the site at the center of the twenty-first century economy: Lithium. That once-obscure metal, long suffering in the shadow of copper, iron ore and other widely cheri