Nearly a half-century ago, Nike co-founder Phil Knight traveled through China on slow train, with passengers stripped to their underwear in the summer heat, and dreamed of selling sneakers. He laid out an ambitious vision—“One billion people, two billion feet”—that called for an aggressive push into the country. By 2010, China was among Nike’s most lucrative markets, offering a blueprint for U.S. companies seeking to cash in on China’s rise. Today, Nike’s China business is flailing—a cautionary tale of an American giant caught in the tar pit of China’s hypercompetitive and increasingly nationalistic consumer market.  Nike’s China revenue over the…