The Guardian view on Ukraine’s counteroffensive: a stunning breakthrough | Editorial

The liberation of a swathe of territory in the country's north-east could be a game-changer for Kyiv

The burnt-out tanks, abandoned crates of ammunition and other evidence of swift, chaotic Russian flight tell their own dramatic story. The stunning, lightning offensive by Ukrainian troops in the north-east of the country constitutes the most significant moment in the war since March, when Vladimir Putin's assault on Kyiv was repulsed and his invading forces beat a hasty retreat eastwards.

Over five days, thousands of square kilometres of the occupied east, including the strategically vital cities of Kupiansk and Izium, have been liberated. According to Ukrainian commanders, Russian troops have been pushed back to the border. The Institute for the Study of War estimates that the counteroffensive has taken control of more territory than Russian forces have managed in all operations since April. Skilful use of western rockets and artillery allowed the Ukrainian military to successfully target Russian supply lines and erode its massive advantage in military hardware. Already low in morale - and lacking elite combat troops who had been dispatched to deal with a prior offensive in the south - Russian fighters abandoned overnight territory that had been won after weeks of attritional warfare.