A Russian drone zips across the computer screen, startling the commanders keeping watch over the battlefield via a live stream in their bunker.

Cigarette in one hand, radio in the other, one of them calls in their own drone to bring it down and warns the soldiers below of the threat. The men are dangerously exposed, on the long walk across open ground from their front line positions. They are being replaced after three months forcing the Russians back.

This is part of Operation Vivaldi, a Ukrainian counter-offensive which they say has liberated 277 sq km (106 square miles) in the eastern Donbas region in recent months.

The name reflects the offensive's four stages, or seasons – like the Italian composer's violin concerto. The successful assault blunted an attempted Russian pincer movement that threatened to encircle the key Fortress Belt cities still under Ukrainian control.

While Russia this month pummels Ukraine from the air, crippling its energy infrastructure and killing scores of civilians across the country, at the front, it is Ukraine that has made recent gains. Kyiv says it has inflicted heavy losses – 8,000 Russian casualties in Vivaldi alone, and close to 50,000 along the front in the month of September – and suffered few casualties in return.

The Institute for the Study of War reported that pro-Russian military bloggers had acknowledged the Ukrainian advances, and expressed fears this could lead to more losses for Russia in the future. No Russian official has publicly acknowledged the Ukrainian gains. Russian ministry of defence briefings say only that they were "repelling attacks" in the Lyman region, or "improving the tactical position at the front".

Despite Ukraine's forward moves, Russian drones are still ever-present. Phoenix, Commandant of the Revenge Brigade's Silver Trinity unit, tells me his men face 10 on an average day.

He is fixed on the live stream as a Ukrainian snare swoops in, hovers for a few seconds and drops a net on to the drone, dragging it from the sky. This Russian drone was for reconnaissance, but if it had locked on to the soldiers, another drone carrying explosives would have followed.

This moment of peril illustrates the layers making up the modern battlefield. The command bunker receives live pictures from a hovering camera, while below a Ukrainian attack drone attacks another enemy spotter which would have called in more flying firepower.

Integrated in all of this is Starshield, the military version of Elon Musk's Starlink satellite communications network, providing broadband connectivity across the battlefield.

Ukraine said this week, as Operation Vivaldi concluded, that the system had restrictions imposed without warning, limiting their capability.

Musk and media reports suggest the order may have come from the White House. While Ukraine is not wholly reliant on Starshield, it is a key tool in their arsenal, vital for interceptor and mid-range strike drones. And knowing this tool can be restricted without any warning or consultation has sparked major concern in Ukraine.

Beneath the battle for aerial superiority, unmanned ground vehicles scurry back and forth delivering supplies, evacuating the wounded or, increasingly, leading the charge against the enemy.

Everything here relies on digital connectivity – to see, to move, to fly, to communicate, to fire. But at the bottom of this stack, it is still human beings in trenches who are holding the ground.

The weary soldiers have made it safely to the command post. After 95 days pushing forward on the front line there is an emotional reunion.

An infantryman with the call-sign Dealer tells me he feels strong, but it is good to be finally heading home: "It's an impressive operation. Over three months, we moved positions four times."

He tells me the most frightening threat was Russian drones, piloted remotely and determined to hunt down their target.

Commandant Phoenix said the preparation for the offensive was "enormous".

"The men trained for months. We had to completely restructure our approach because previously we had been defending, and now we had to go on the offensive."

Robots and drones led the assault on Russian positions and, for the first time, remote-controlled explosive vehicles were dropped behind Russian lines – 250 Russians surrendered. According to Ukrainian commanders, their year-long campaign has freed 16 settlements from Russian occupation.

In Karpivka, a village occupied since April, the Ukrainians found one local resident remaining – 61 year old Volodymyr Zamota, the last man standing when his neighbours fled the Russian advance in 2025. He says he survived for eight months in total isolation.

"As they say, hope dies last," he told me. "I'm the only person left in the whole village, and the village has been almost completely destroyed."

"I thought I would live to old age without experiencing anything like this, but then it happened. It's a terrible tragedy".

That devastation defines the region Ukraine has just recaptured. It's still too risky for residents to return, if they even have a home intact. But Ukraine's soldiers are celebrating this regained ground, the halted Russian advance and the future potential this operation may present.

"The real value of this is securing advantageous positions, favourable lines, and a bridgehead that grants us a superior position," Andriy Hitt, Revenge Bridge chief of staff, explained.

"This allows us to create the necessary conditions for subsequent successful operations, seize the initiative in battle, and plan future successful manoeuvres… each of these actions is a building block towards victory."

All this could be threatened by the limitations on US technology, and American intelligence. Relations between Kyiv and Washington are at an all-time low.

This week President Zelensky said he felt "betrayed" by Donald Trump, while the US leader declared he was "not a fan" of his Ukrainian counterpart, saying he was harder to deal with than Vladimir Putin.

Trump says Ukraine's strikes on Russian oil refineries have hiked oil prices. Ukraine says the US and Israeli war against Iran is the cause.

But despite the diplomatic divisions, among the soldiers we met, morale is high. Dealer says Operation Vivaldi has renewed his belief Ukraine can win the war.

The unit is ensuring Volodymyr, Grandpa as they call him, has enough to eat – drones drop off food parcels on their way to feed soldiers at the front.

I asked Volodymyr if he believed Ukraine could win. "Yes, of course I do. I would just like to know when it will happen, when all of this will finally end."

Additional reporting by Kostas Kallergis and Anastasiia Levchenko