Over the past few days, the Ukrainians have upended assumptions about the war with Russia. They have shown it was wrong to predict that the conflict was inevitably going to turn into a war of attrition. They have advanced at speed, reclaiming, according to reports, 1,000 square miles of territory in a week. It’s not clear yet whether they will be able to secure these gains. But for now, Russian forces are demoralised and do not have a conventional response.

For Ukraine’s president Zelensky, the military advance is particularly well-timed. It shows his Western backers that the Ukrainians can regain territory and makes it easier to resist attempts to pressure Kyiv to the negotiating table. Indeed, those calling for even greater Western military support to Ukraine have been emboldened by the offensive.

But the concern is how Vladimir Putin might escalate things. The upset evident among hawks in Russia is a reminder of the dangers for the regime in losing face in Ukraine. Since their retreat, the Russians have targeted more civilian infrastructure — Kharkiv has been left without power and water. Obviously, if Russia is prepared to take out power networks going into winter that is going to have consequences. But Zelensky’s speech last night – in which he told Russians ‘Cold, hunger, darkness and thirst are not as terrible and deadly for us as your ‘friendship and brotherhood’ – made it equally clear that Putin’s tactics won’t change Ukraine’s strategic calculations.

At this point, people often talk about an off ramp for Putin. But leave aside the strategic debate over whether one should be offered, there is currently no sign that Putin is interested in taking one despite all the setbacks he has encountered. Putin has destroyed Russia’s role as an energy supplier to Europe in the last few months. Even if this war finished soon, no one would want to go back to their previous dependence on Russia given how the Kremlin has weaponised gas and oil: Putin has raised the stakes for himself still further in Ukraine.