New phase of Ukraine war brings no obvious route to end fighting

An eight-mile convoy, spotted on Friday by satellite imagery, 50 miles east of Kharkiv, is likely to be heading for Izyum, once again bringing to mind one of the early images of the war. Russian forces have been, for several days already, trying to push from Izyum south to Slavyansk, but not so far making much progress.

Elsewhere in the east, Russian forces are getting edging closer to seizing control of Mariupol, cutting the city into two on Sunday, according to the Institute of the Study of War, at a high cost to the attackers and a far more fearful cost to its citizens.

Its focus in the first instance will be trying to stem the Russian advance, to avoid its forces being enveloped in Donbas, and instead grind Russia to a something like a stalemate as both sides become increasingly exhausted after what would be more than two months of fighting.

That would nevertheless leave Ukraine largely cut off from the sea, and Russia with a land bridge from Donetsk to Crimea. Ukraine may not be demilitarised as Putin demanded, but its economy is nevertheless devastated, shrunk by an estimated 45% this year, according to the World Bank.

The question for the west, for whom Ukraine is effectively fighting a proxy war, is whether to step up supplies so that Kyiv can turn the tide on land, force Russian forces out of Kherson near the mouth of Dnieper River in the south, and drive the invaders back elsewhere in the Donbas.

The refusal to supply Russian-designed fighter jets from eastern-bloc Nato members suggests the US, in particular, is nervous not just about provoking an unpredictable Kremlin but also about altering the balance too far. A tipping point could be whether Poland is allowed to supply about 100 Russian T-72 tanks it has in its arsenal.