It is time the Western powers supporting Ukraine in its defence against Russia’s attack engaged in a serious debate about their own war aims. They may not be identical to Ukraine’s. But the way the Ukrainian military effort has become more and more dependent on outside help means some moral responsibility for the eventual outcome has to be shared. Would Nato, the European Union, the United States and the United Kingdom support a Ukrainian effort to drive Russia out of Crimea, for instance? If not, had they not better say so soon?

Ukraine’s military tactics have been defensive. It has successfully resisted the Russian invasion, especially its attempt to capture the capital Kyiv, decapitate the government and bring the country under its control. Russia has been forced to abandon that objective, at least for now. It is concentrating on carving out a slice of eastern Ukraine where there is a significant Russian-speaking minority and calling it part of ancient Rus, and on establishing a land bridge between Crimea and south-west Russia.