President Trump and other mercantilists are hoping that his tariffs will drive U.S companies out of China, perhaps even back to the United States. They can keep hoping. It’s not likely to happen. In a further escalation of his trade war, on August 23 Trump “ordered” U.S companies to leave China, or even return to the United States. This prompted a debate among legal scholars as to whether he even has the authority to do that. Regardless of whether he does or doesn’t, it is unlikely to have any impact. A proviso is called for here. Some U.S companies are...