Josh Hawley doesn’t think Rahm Emanuel is fit to serve as U.S. ambassador to Japan because he “clearly does not understand the China threat.” The evidence? In an interview with the Washington Free Beacon, the Missouri Republican cited Mr. Emanuel’s pursuit of Chinese investment as mayor of Chicago. That’s a stretch. Part of a mayor’s job is to seek investment for his city. Until very recently, almost any mayor or governor would have welcomed Chinese investment. Even under Donald Trump, who has never been accused of being soft on Beijing, China wasn’t blocked from buying U.S. Treasury bonds. It still isn’t. Sen. Hawley has a legitimate point about Chinese investment, but it has little to do with mayors. This is because Beijing has made clear its companies are expected to support its military and intelligence ambitions. The sheer size of China’s economy and its integration into global supply complicates decisions that would otherwise be left to the market.