It is an image of defiance. A girl poses in the red dress she planned to wear for her school prom - an event that never happened. On 27th February, the school took a direct hit from a Russian bombardment. It ruined, says 16-year-old Valerie, "all our plans that we so dreamed of". But continuing missile strikesOn Tuesday they killed one person and wounded three others. have not broken Ukraine's spirit.

If Valerie's plans have not worked out, nor have President Putin's. KharkivUkraine's second-largest city. Before the war, it had a population of 1.5 million. is close to the Russian border and was a prime target for the invading forces. But it was never taken.

Nor did the Russians have the quick victory they expected in Mariupol, where determined resistance kept them at bay. On Tuesday, two of its captured defenders, both British, were charged by a pro-Russian court in DonetskUkraine's fifth-largest city. In 2014 Russian-backed separatists seized control and said they were setting up the "Donetsk People's Republic". with trying to "seize power".

Legally, this makes no sense, since Aiden Aslin and Shaun Pinner were fighting for Ukraine, of which Donetsk is part. It is one of many bizarre situations thrown up by a war which, in the words of the UN's Amin AwadThe UN's assistant secretary-general and crisis co-ordinator for Ukraine., "has and will have no winner."

The UN estimates that 15.7 million people need humanitarian aid. The war, Awad says, has "engulfed virtually all aspects of civilian life". Over 14 million people have fled their homes - "a scale and speed of displacement not witnessed in history."

Most experts agree that, after failing to capture Kyiv, the Russians are making more progress by concentrating their forces in the east. According to retired US general Stephen TwittyA former deputy commander of US forces in Europe., their plan is now to obliterate every city that stands in their way.

"They're not putting a bunch of combat power with infantry forces and tanks in there," he says. "They've taken all their artillery and they're treating it like Mariupol." The Ukrainians, he argues, will never have the military strength to drive the invaders out.

On the other hand, says Stephen J Hadley, a former US national security adviserA member of the government who is in charge of defence., the Ukrainian forces have shown themselves to be more enterprising than the Russians. He believes they can "grind down" the invaders "so that you get to the point where there is a stalemateA position in chess where neither player can win. It derives from the Old English stale, meaning a position, and Persian mat, meaning dead.."

The hope is this will lead to peace talks. But with the Ukrainians determined not to concede any territory, and Putin needing to gain territory to save face, there is little room for compromise.

Yes: The fighting is hugely costly for both sides. By the end of the year, Russia will feel the deep impact of sanctions, while countries suffering from energy and grain shortages will pressurise Ukraine.

No: Neither side is in the mood for negotiation, and both will fight to try to gain a military advantage. Both have enough soldiers and supplies of arms to continue the war for years.

Or... As Amin Awad says, there will be no winner. Russia's new approach to the war means that whoever gains control of the territory fought over will just be left with devastated cities to rebuild.