How did the Ukraine crisis begin? First gradually, then suddenly.

Less than three months ago, as December gave way to January, there was much fevered debate in Europe and beyond over the significance of the Russian forces so ominously gathered on the frontiers of Ukraine. Vladimir Putin was obviously up to no good. That was a given. But few believed that he was about to unleash an invasion of such scale and ferocity that it would invoke comparison with Operation Barbarossa, Hitler’s assault on the Soviet Union in 1941.

In Washington, President Joe Biden spoke of the danger of a possible Russian incursion into Ukraine, most obviously in the Donbas region, a large part of which was already controlled by Russian-backed separatists. But while this would, it was said, be resisted by America and by NATO, it was far from a done deal. Biden had much else on his mind, not least his plummeting popularity with the American public and the failure of his much vaunted Build Back Better agenda.