London

It’s ancient history now, but Boris Johnson’s March 9 press conference will go down as the critical event in the U.K.’s encounter with the coronavirus pandemic. At that precise moment it first became unclear who was really running the show.

The event was supposed to alert the public to the phased response the prime minister’s government planned to adopt. Implicitly admitting that stopping the disease was implausible, the goal would be to slow the spread to protect as many vulnerable people as possible while preventing an overload on the National Health Service.

Mr. Johnson and his scientific advisers evinced a recognition that the most drastic countermeasures, such as the total lockdown then in effect in Wuhan, China, would not be sustainable. So the British government, relying on internal scientific models, would ratchet up its response gradually. Start with hand-washing and mild forms of social distancing, and only later close schools or shut pubs.

That was the plan on March 9, anyway. Then the journalists started asking questions.