One reason retailing has become ground zero for the new protectionism is that China’s $70 billion-a-year market for large grocery stores is still up for grabs. The industry, expected to double in size by 2015, is far more fragmented and regional than that in Europe or the U.S… Wal-Mart, with 353 stores, has an 11.2 percent share, second only to the 12 percent held by France’s Auchan.