A little over a decade ago, a diplomatic row with Japan would have been enough to bring people out into the streets in China or at least stir a patriotic retail boycott.
In 2012, for instance, tensions boiled over after Tokyo bought and then nationalised three of the Diaoyu Islands, a group of eight uninhabited islands in the East China Sea that Japan calls the Senkakus.
China and Japan have a long-running territorial dispute over the islands and authorities appeared to tolerate the…