A reported ban on Apple iPhones in government offices across China wiped millions of dollars off Apple's share price last week, in the latest chapter of a tech war between the United States and the world's second-largest economy. Yesterday, China said there is no ban. That statement was followed some hours later by White House National Security spokesman John Kirby saying: "I don't want to get ahead of where we are right now. We're watching this with concern. Clearly, it seems to be a piece of the kinds of aggressive and inappropriate retaliation to U.S. companies that we've seen from...