President Trump says he wants Xi Jinping, China’s leader, to call him to talk tariffs. Mr. Xi is ghosting Mr. Trump, and markets are plummeting.

Mr Trump’s breezy style has long disconcerted China’s leaders. In the spring of 2017 he called Mr Xi so often to ask for help with North Korea that Chinese envoys eventually delivered a discreet message to American contacts. Mr Xi is “not our North Korean desk officer”, they pleaded: let underlings handle most of this.