Since the end of the Cold War, the world's powers have generally agreed on the wisdom of letting market competition—more than government planning—shape economic outcomes. China's national economic strategy is disrupting that consensus, and a look at the ascent of solar-energy magnate Zhu Gongshan explains why. A shortage of polycrystalline silicon—the main raw material for solar panels—was threatening China's burgeoning solar-energy industry in 2007. Polysilicon prices soared, hitting $450 a kilogram in 2008, up tenfold in a year. Foreign companies dominated production and were passing those high costs onto China. Beijing's response was swift: development of domestic polysilicon supplies was...