BRUSSELS — President Emmanuel Macron, never very popular, has touched his highest approval ratings in France since the onset of the coronavirus. As Italy has been devastated, Prime Minister Giuseppe Conte has hit a remarkable 71 percent, up 27 points. Even in Britain, where Prime Minister Boris Johnson waffled over a strong response, then became seriously ill himself, the government is the most popular in decades.

There is nothing like a good crisis to get diverse populations to rally around their leaders. When people are confused and afraid, they tend to trust their governments, because to think that the authorities are themselves confused and afraid, let alone incompetent, is too much to bear.

The question is whether that will last once the crisis eases, criticism mounts and normal politics resumes. Usually, it does not last long. Formal inquiries into the inevitable errors and mistakes soon follow, and voters, if allowed, often take their revenge, even on the most effective leaders.

And it is safe to say that many of those getting a boost for the moment have been less than effective, judging by the crushing toll of a virus impervious to partisan bluster and unforgiving of mistakes.