Parked up on a winter-grey Donbas wheatfield, a Ukrainian military officer pointed out the distant skyline of the city of Avdiivka – or what was left of it.

On one side was the chimney stack of its Soviet-era coking plant. On the other, amid palls of battlefield smoke, were rows of war-ravaged housing blocks. It was a vast panorama of death and destruction – and, in the officer’s bitter words, a symbol of Ukraine’s betrayal by the West.

“If we’d had enough shells, we could be destroying the enemy from spots like this field, as we have a perfect vantage spot,” he said as artillery boomed in the background.

“Even Joe Biden has admitted that we haven’t given enough military aid to Ukraine. Now we’re in the position where we have to decide which village we hand over next to the Russians.”

Russian troops finally raised their flag in Avdiivka last Sunday, handing Vladimir Putin his first victory since taking nearby Bakhmut last May – and one conveniently timed for next month’s Russian presidential elections.

True, only a leader like him would see anything to boast about: the grimy industrial town of 30,000 people is a third of the size of Scunthorpe, and taking it has required the lives of an estimated 20,000 Russian troops. But it is hardly the finest hour for Kyiv’s foreign backers either.

Avdiivka’s fall is not just a story of Russian brute strength, but also of faltering Western support. Thanks to dithering over US and EU military aid packages since the autumn, Kyiv’s forces are running dangerously short on every front – artillery, drones, manpower and, to some extent, morale.

While the EU promised to send one million shells to Kyiv by March, it is set to deliver only 500,000. The White House, meanwhile, has been unable to convince Republican leaders to pass a $60 billion support package for Ukraine, leaving the US currently unable to send any ammunition whatsoever to the front.

The troubles that have resulted for Ukraine’s soldiers were clear when the officer took The Telegraph to meet a team operating a Grad rocket launcher, based within striking distance of Avdiivka.

Normally capable of raining 40 missiles onto Russian positions in a single burst, the Grad had lain silent for three days because of a lack of ammunition, said “Sergeant Andrew”. 

The 28-year-old declined to specify exact figures of the shortfalls, but his soldierly vernacular spoke volumes.

“Things are f-----,” he said, in a stark warning delivered ahead of the second anniversary of the Russian invasion on Saturday.

“There’s no point in going into battle if we haven’t got enough ammo. It’s not that we’ve lost our spirit. We just don’t have the means to fight. If we have another few years like this, it will be a disaster – we’ll either run out of people, or everyone will just leave the country.”

Earlier this week, Volodymr Zelensky, Ukraine’s president, warned that “the situation is extremely difficult in several parts of the front line,” and said Russia was “taking advantage of the delays in aid to Ukraine”.

By contrast, Putin – who only last summer was fighting for his survival after a coup attempt – was in bombastic mood on Thursday, taking a ride on a new nuclear-capable strategic bomber jet.

Western officials insist the capture of Avdiivka will not mark the start of a collapse of Ukrainian forces. “The Russians lack the combat effectiveness to be able to move on from Avdiivka,” one said on Thursday. “They almost certainly need a period of rest and recuperation.”

But in the days since the Russian flag was planted in the town, other spots along Ukraine’s 600-mile front line have also come under pressure.

In the village of Robotyne, nearly 200 miles south-west, Russian troops have launched a sustained assault, seeking to take back one of Ukraine’s few hard-won prizes from last summer’s counter-offensive.

To the north in Kupiansk, which Ukrainian troops recaptured in a lightning offensive in the autumn of 2022, a Kremlin force of around 40,000 is attacking.

And near the Black Sea city of Kherson, a Ukrainian bridgehead at Krynky, on the Russian-held side of the river Dnipro, is under increasing pressure.

The combined attacks seem part of a Kremlin strategy to undo two years of near-constant Ukrainian military gains. At an anniversary press conference this time last year, Mr Zelensky said the idea of the conflict lasting another full year was a prospect he “didn’t even want to think about”. Now it is a reality.

Among the last people to see Avdiivka before it fell into Russian hands was Pavlo Dyachenko, a member of Ukraine’s White Angels volunteer police rescue unit. He evacuated some of the city’s last remaining civilians to safety a fortnight ago.

“There’s always a few old people who only leave once their houses are destroyed,” he said. “There was constant shelling, with everything on fire, and the aviation bombs were terrifying – even for someone like me.”

It takes a lot for someone like Mr Dyachenko to say that things are bad. A veteran rescuer, he shot to fame in Ukraine last May when he was photographed escorting a six-year-old from heavy shelling in Bakhmut.

His craggy face later featured on a postage stamp of Ukrainian war heroes, an honour also given to the soldier who radioed “Go f--- yourself” to a Russian battleship.

That, though, was when the war was going Ukraine’s way, and Kyiv felt it had the West’s unwavering support. Now, even greater courage is required – to keep going when exhausted, and when Russia once again seems to hold the aces.

With around 70,000 war dead, Ukraine is running out of frontline heroes like Mr Dyachenko. Some military units are at a third of their strength and relying on replacements who are either old, inexperienced or mediocre.

“Our commander’s a legend – he’s been fighting since 2014, and he goes into the trenches with us,” said Vlad, 29, a frontline infantry soldier drinking at a coffee kiosk while on leave in Selydove, 25 miles east of Avdiivka. 

“But our oldest guy is 50 and he’s not very fit – we just don’t have enough young people any more.”

Right now, towns like Selydove act as rearward echelons for Ukrainian forces, who have come here for much much-needed showers after fortnight-long stints in the freezing trenches round Avdiivka.

But even here, the war feels as though it is getting closer again. A street away from where Vlad stood, a housing block had been torn apart by one of half a dozen missile strikes that had landed over the previous week.

In nearby villages, stacks of “dragons teeth” – concrete pyramids designed to halt tank advances – are piled up, ready to be scattered over surrounding fields.

To outside eyes, this corner of eastern Ukraine does not seem like much worth fighting for. It is an endless sprawl of coalmines, slagheaps and Stalin-era steel plants, a rust-belt unpolished since Soviet times.

Some factories are even still named after Communist heroes like the miner Alexei Stakhanov, famous for his slavish devotion to meeting Soviet production targets.

A century on, that very same Stakhanovite formula of quantity over quality is allowing Moscow to prevail on the battlefield.

“In my sector of Avdiivka, the Russians were losing about 25-40 soldiers daily, but even if they do 15 failed attacks, they just carry on and hope to succeed on the 16th, using their stocks of old Soviet artillery to overwhelm us,” said Nikolai, another soldier who had just left the town.

“If we hadn’t pulled out, we’d all be dead. Frankly, we just feel f----- all the time – I’ve been fighting since 2014, and all that keeps me going now is anger.”

With US funding for Ukraine stalled by pro-Trump Republicans, European capitals are trying to take urgent measures to step into the breach.

On Monday, Denmark said it would give its entire stock of artillery shells to Ukraine. 

But it may be too little, too late. At one artillery unit outside Avdiivka, soldiers told The Telegraph that only two of their 18 Howitzers are currently operational because of the shortages.

“A year ago, we had plenty of shells – today we have hardly any,” said Chief Lieutenant Andrew, 32. “Artillery cover helps protect the lives of our infantry, but right now we can hit only a few of the targets that we want to.”

The Kremlin’s upper hand is not just thanks to its superior reserves of ordnance stocks. 

In a conflict that has merged World War One trench fighting with cutting edge digital technology, it has also improved its drone warfare – until very recently, an area where Ukrainian forces had seemed ahead.

FPV or First Person View drones, which carry grenades, and which the operator can fly down onto infantry troops like giant mosquitoes, are particularly lethal. 

While both sides use them, the Russians have recently acquired FPVs equipped with night vision, disrupting Ukrainian supply lines to Avdiivka that relied on the cover of darkness.

“The FPVs are a nightmare – I lost a friend of mine to one just yesterday,” said Maxim, 30, on R&R after fighting in the village of Klishchiivka, outside Bakhmut.  

“We get them every hour, sometimes every 40 minutes, sometimes five or six on different frequencies so that our anti-FPV guns can’t jam them. We’ve been trying to shoot them down with old duck-hunting rifles.”

Another Russian game-changer is the drone’s bigger, badder cousin, the guided aerial bomb. Dropped from a plane and then guided onto a target by satellite, the bombs deliver a cruise missile-sized payload at a fraction of the cost.

“The Russians have intensified their guided aerial bombs since New Year,” said a soldier with a reconnaissance team outside Avdiivka, showing The Telegraph drone footage of a guided aerial bomb ploughing a quarter of tonne of high-explosive into a school. “It’s been just total s--- since.”

Despite the horrors, there seems little obvious blunting yet of Ukraine’s most important weapon – fighting spirit. 

But many soldiers now complain of being made to fight “on enthusiasm alone”, and occasionally, there is even sympathy for Mr Trump’s pledge to make Ukraine negotiate should he be elected US president later this year.

“You want the view of a guy from the trenches?” asked one soldier at the coffee stand in Selydove. “We’re having big losses and we need help – things are far harder than they were a year ago. If Donald Trump wants to stop our weapons, f--- him. If he wants to stop the war, though, I’ll vote for him myself.”

In the same breath – which, it should be noted, carried a whiff of illicit R&R boozing – the soldier ruled out any end to the war until Ukraine had regained all its land, including not just Avdiivka but the rest of the Donbas and all of Crimea.

Right now, such goals look more distant than ever – and according to soldiers like Maxim, the cost of regaining that territory is only likely to get higher.

“The longer the Russians fight, the more they learn from their mistakes,” he said, as he headed off for his first shower in a fortnight. “They’re much better now than when the war started. I think we can still win – the question is what price we will pay.”