The move against The Wall Street Journal will compound the regime’s problems, since reporting by foreign news organizations has often been critical in filling the omissions and straightening the distortions of China’s official media. It was The Journal that did some of the most pathbreaking work to expose the scale of the country’s environmental catastrophes, just as it was The Times that exposed the extent of graft at the top of the Chinese leadership pyramid. Other news outlets, particularly Reuters, have done vital reporting on the frauds and scams endemic in China’s economy.

Suppress this kind of reporting, and the first people who will suffer information blindness are China’s leaders. Every dictator needs subscriptions to The Journal and The Times, even if they come — like smutty magazines of yore — in inconspicuous brown envelopes.

It’s always possible that the regime will think better of its move to expel the reporters or at least quietly let them return in a few weeks’ time. Wise leaders, facing a monumental crisis brought on by their own irrational distrust of information, would at least learn the lessons of their folly. But there might be a truth in China even more frightening than the coronavirus — foolish rulers.

For that, no vaccine has ever been invented.