Outside the bombed remains of the police station in downtown Kupiansk, a notice board displays the mugshots of wanted local criminals.

Among them is a photo of one Vladimir Putin – sought in The Hague for war crimes, and wanted around here for trying to steal Kupiansk for Russia at the start of Ukraine’s invasion two years ago.

It was not the most successful of heists – after six months of brutal occupation, Russian forces were routed from Kupiansk by a Ukrainian counter-offensive in autumn 2022.

But like many repeat offenders, Mr Putin seems unwilling to learn from past mistakes – hence the sounds of battle returning to Kupiansk as Kremlin forces seek to take the town once again.

“They’re shelling nearly every day right now – a while back, they dropped 18 aircraft bombs in ten minutes,” said Oleg, a municipal workman, as he patched up a bomb-wrecked shop off Kupiansk’s main square last week, where a missile tore a giant crater the day before. “We always knew the Russians would try to come back, we just hope they don’t succeed.”

Perched on a hilltop just 25 miles from the Russian border, Kupiansk lies at the northeast end of Ukraine’s 1200-mile front line, which is under pressure at every point right now as Kyiv struggles with shortages of troops and munitions.

Earlier this month, Ukrainian officials said that 40,000 Russian troops had massed outside the town – a force of similar size to that which captured Avdiivka, 150 miles south, last week. Retaking Kupiansk would give Russia a launch point to press on towards Kharkiv, Ukraine’s second-largest city, 100 miles west.

While Kupiansk now echoes round-the-clock artillery duels, fighting also rages in the forests towards the Russian border, where Ukrainian troops find themselves in a modern-day Ardennes.

“It has been crazy, intense,” said Petro, 38, one of four Ukrainian infantrymen drinking at a coffee stand in Kupiansk last Saturday. “Sometimes we end up in trenches where we occupy one part, and the Russians occupy the other – maybe just twenty metres away.”

Around Christmas, Petro added, they had been close enough to hear the Russians talking, although there had been no repeat of the famous Yuletide truces of World War 1 when British and German troops played football together.

“All we did was shout ‘f— you’ and throw the odd grenade at each other,” he said. “At a time like that you just focus on survival.”

While the Russians have far more troops and artillery, Kupiansk’s geography favours its defenders. Its hilltop position gives Ukrainian troops a view towards the nearest Russian positions five miles away, and the town also sits on the River Oskil, which at this time of year is a muddy, ice-bound swamp.

Still, the Russians’ use of drones makes soldiers vulnerable anywhere. Some drones, Petro said, dropped smoke bombs and tear gas, designed to force soldiers out of their trenches.

“It’s horrible, you can’t see through it or breathe in it,” he said. “Then, when you run out in the open, they drop bombs.”

Whatever happens, the Russians are likely to have a harder time taking Kupiansk now than they did in February 2022, when the town’s pro-Kremlin mayor, Hennadiy Matsehora, surrendered it without a fight. He claimed this was to avoid bloodshed, although he was later accused of treason by the Ukrainian government.

To start with, the Kremlin tried a charm offensive, hoping to make Kupiansk a showcase for the benefits of Mother Russia’s embrace. Russian officials set up aid stops and distributed a free newspaper, while Mr Putin’s own United Russia party opened an office. But those who organised anti-Russian protests were hauled off to jail, where interrogators would fit them with gas masks that pumped searing hot air into their lungs.

“The Russian commanders were trying their best to be nice, but really, there was no law here unless you had a Kalashnikov,” said Oleg, the workman. “We also had militias from the Russian separatist areas coming in to loot.”

By summer 2022, most of Kupiansk’s 30,000 population had fled, and a parade to celebrate Russia’s official flag day that August was sparsely attended. The following month, the flag was abruptly torn down as Ukrainian forces mounted a lightning counter-offensive that reclaimed Kupiansk and much of the rest of the occupied northeast.

In the past six months, however, Russian forces have re-advanced, forcing many Ukrainians who had moved back to Kupiansk to evacuate once more.  Today, Kupiansk is a bomb-ravaged ghost town, with the daily services at the central church, St Nikolai’s, attracting just a few anxious-looking attendees.

Yekaterina Naidenova, 33, a Kupiansk GP, has spent much of the war living with her mother in the family’s beetroot cellar, the only place they feel safe from ordnance.

“I was here when the Russians first occupied, and I don’t want that again,” she said. “I’d like to stay here in Kupiansk as it’s my home, but I really don’t know what I’ll do if the Russians regain control.”

Even her beetroot cellar is probably comfortable compared to the troglodyte conditions of the Ukrainian artillery crews in the fields outside Kupiansk, who stay in bunkers dug ten feet into the ground. Crews of six live and sleep in a space the size of a snooker table, with bare earth walls and floor. 

Thanks to the near-constant presence of Russian spy drones, the only times they go out is to fire their Soviet-era Howitzers, which are concealed under camouflage in the fields’ treelines.  

Here, any sense of the war going decisively in favour of one side or the other side seems limited.

“Sometimes we win, sometimes they do,” shrugged one artillery crew commander, Yuri, who serves with the 57th Motorised Brigade. 

“They have five times more shells than us, but we’re still not letting them take Kupiansk. Three days ago, for example, they tried a serious attack, but we destroyed some of their armoured personnel carriers and some of their infantry.”

In between fighting, there is little for the crews to do but sit in their bunkers, smoking, swapping jokes, and checking their phones for messages from their families, whom they haven’t seen for three months.  

Not all the news from home is good. On New Year’s Eve, one crewman, Sasha, 45, learned that his son had lost a leg from a Russian artillery blast while serving on Ukraine’s southern front.

“I’m just glad he’s still alive,” he said. “Do we fear something like that happening to us too? Yes, of course we do – but if we were all too afraid to fight, there’d be nobody to defend the country.”

With that, news came over Yuri’s radio that the sky was now clear of drones, and the crew went out to fire several shells at some Russian infantrymen 10 miles away.

Many of those infantrymen would no doubt be the same age as Sasha’s son. Yet as long as they remain loyal to the man on the “wanted” notice outside Kupiansk’s police station, the Ukrainians have no sympathy for them.

“They came here to kill us,” said Alex, another crewman, lighting up another cigarette. “We are defending ourselves, that’s all.”