The irony for Mr Putin is that, if he had simply let events take their course, sanctions on Russia could have been eased in the natural run of events — even with Hillary Clinton in the White House. Mrs Clinton had already tried one “reset” with Russia as secretary of state, and might have been prepared to try another. Many in Europe were also tiring of sanctions on Russia.

When the Mueller inquiry reports, there is likely to be a renewed spike in American outrage towards Russia. The most obvious threat is posed to Mr Trump. But the Mueller inquiry also poses an indirect threat to Mr Putin. He will contest a presidential election in March and faces a re-energised opposition, led by the popular and daring Alexei Navalny, and a deteriorating economy that has hit Russian consumers hard. Even though very few people expect Mr Putin to lose the election, the pro-Putin euphoria of a couple of years ago is clearly fading. Articles about the post-Putin era have begun to appear in the Russian media.