Look at Navalny. Hours after he had been handcuffed and detained, for what everyone presumed was five years, more than 10,000 gathered outside the Russian parliament to protest. His name trended on Twitter — and he was released, even allowed to continue to run for mayor of Moscow, pending his appeal.

What then might a strong European reaction achieve?

Putin likes to humiliate. In Britain, he was late for David Cameron in Downing Street and had no manners to wait for all the G8 leaders to be served at dinner before starting to eat. In Germany, he meets Angela Merkel with huge scary dogs because he knows she fears them. In Moscow, he makes every EU-28 leader that comes to see him wait hours — to feel like a supplicant.

Europe needs to prove something to Putin.

Europe needs to prove to Putin that repression and persecution have costs — that if this is just the beginning of a wave of arrests, by the end of it he will have lost the Kremlin’s free pass to Europe’s banks and havens. This would make his henchmen pull him back from the worst.

Europe needs to speak to Putin in a language he understands.