Trade: President Obama has fired the opening salvo in a trade war with China by slapping 35% tariffs on its tires. But besides giving China a kick, this protectionism will harm Americans across the economy.Sec. 421 of the 1974 Trade Act, intended to control surges in imports. But the markets paid attention. Global stock futures tumbled over the weekend. Asian markets dropped sharply Monday, fearing a wave of U.S. protectionism. China called the U.S. move "rampant protectionism" and vowed to investigate dumping charges against U.S. auto parts and chicken, two industries that have made inroads into the China market. The...