As Donald Trump has pulled the United States inward under his "America First" presidency, China has had only halting success at capitalising on a global leadership vacuum, presenting openings for a more internationalist Joe Biden administration if he wins next month's US election.

Under Trump, Washington abandoned the Paris climate pact, the Trans-Pacific Partnership, the UN Human Rights Council and Unesco, and ditched the Iran nuclear deal. It has announced that it will withdraw from the World Health Organisation (WHO) next July and has crippled the World Trade Organisation by blocking appointments to its appeals panel.

Beijing, which accuses Washington of being "addicted to quitting", has struck a more globalist posture under President Xi Jinping...