We have been here before. Russia is at the centre of an international crisis of its own creation. And we know how it plays out: briefly there is shock in Western capitals, quickly followed by outrage. This is entirely justified given that Alexey Navalny, Russia’s most prominent opposition figure – and the second most popular politician in the country – is lying in a coma in a Berlin hospital having been poisoned, according to the German government, by the nerve-agent Novichok.