To ask “what if Ukraine loses?” was once a tactic favoured by those looking to berate its Western allies into sending more money and weapons. Increasingly the question feels less like a thought experiment and more like the first stage of contingency planning. After a gruelling few months on the battlefield, gone are last year’s hopes of a Ukrainian counter-offensive that would push Russia back to its borders and humble Vladimir Putin. These days it is fear that dominates: that an existing stalemate might crumble in favour of the invader, or of Donald Trump coming back to power in America and delivering victory to Russia on a silver platter. Although a vanquished Ukraine has become a less far-fetched prospect, it is no less frightening. Sobering as the return of war on the continent has been, a successful invasion reaping geopolitical rewards for Mr Putin would be much worse.