The United States and China look like two punch-drunk prizefighters squaring off for a major championship fight. They have no good reason to fight and every reason to cooperate now that both their stock markets have been in turmoil. Six hundred point market swings down and then up look like symptoms of economic nervous breakdown. Factions in both nations are beating the war drums, putting presidents Donald Trump and Xi Jinping under growing pressure to be more aggressive. Trump shoulders much...
