China's air safety authority was one of the first to ground the Boeing 737 Max 8 jetliner after the recent devastating Ethiopian Airlines crash. Some have questioned the motivations of China's Civil Aviation Administration. The Boeing plane is, after all, on a list of goods to be purchased should the United States and China agree to end their trade war.

But assume that China's motivations were actually powered by a concern for passenger safety, and the story becomes more interesting. And there might be a moral, too.