There is a mood abroad that says history will record that sanctions against Russia marked the start of an epochal retreat from globalisation. I heard a high-ranking German official broach the thought the other day at the German Marshall Fund’s Stockholm China Forum. It was an interesting point, but it missed a bigger one. The sanctions are more symptom than cause. The rollback began long before Russia’s Vladimir Putin’s war against Ukraine.

The case for calling a halt to business as usual with Moscow is self-evident to anyone who considers that international security demands nations do not invade their neighbours. The valid criticism of the west is that it has been too slow to react. At every step, the Russian president has ruthlessly exploited US hesitation and European divisions.

He will do so until Nato restores deterrence to the core of European security. Mr Putin’s irredentism demands tough diplomacy stiffened by hard power. He will stop when he understands that aggression will invite unacceptable retaliation. To make deterrence credible, the alliance must put boots on the ground on its eastern flank. The Baltics have replaced Berlin as the litmus test of western resolve.