It has been a rare thing in recent years to see the government of China looking unsure of itself, but among the many consequences of the coronavirus, this is one of the most striking. Trade wars with the United States, outrage at the oppression of human rights, even riots on the streets of Hong Kong — Xi Jinping, the most powerful Chinese leader since Mao, has sailed serenely through all of these storms. However, coronavirus is a threat of a different order, the kind of “black swan event” whose potential for political damage is still unmeasurable. Apart from killing people, it is making the unafflicted population angry, scared and discontented, and it is isolating China from a world on which its economy has