Ukrainian President Volodymyr Zelensky last week heralded the success of Operation Veles, during which Kyiv sent troops deep into a disused gas pipeline in the Kupiansk region to confront Russian troops. These underground tactics, which Russian forces have been using for more than two years to slip past Ukrainian lines, are giving Kyiv a new strategy on the battlefield.

After years of fighting raged across the fields and forests of Ukraine and up into the skies above them, a new front has opened up in the war: beneath the earth. The Ukrainian army has now taken the fight to the Russians in the network of disused underground gas pipelines and tunnels around the town of Kupiansk in Ukraine’s east, the New York Times reported at the end of October.

For almost two weeks, the Ukrainian army has been showing Western media outlets the grim reality of its efforts to seize control of a gas pipeline that passes beneath the Oskil River and into this frontline city that the Russians have been fighting to capture.

Kyiv in October launched Operation Veles, which Ukrainian President Volodymyr Zelensky last week described as a “great success”. Throughout the campaign, specially trained and equipped Ukrainian soldiers advanced 15 kilometres along a gas pipeline with a diameter of just 1.2 meters to secure the tunnel’s entry.

The president said that troops had also managed to “eliminate” around a hundred Russian soldiers and take more than 30 more prisoners during the fierce fighting that raged unseen in this underground battlefield.

Huseyn Aliyev, a specialist on the war in Ukraine at the University of Glasgow, said that the operation marked Ukraine’s adoption of tactics long practiced by Moscow.

“It is becoming very widespread, but it's not a new thing – Russians were the ones who started using it,” he said. “This is the first time I know when Ukrainians have started using the same methods.”

A winning tactic While Ukraine was not the first side to take the fight into the industrial pipelines criss-crossing much of the country, Zelensky said that Kyiv had now made it their own.

“Ukrainian warriors have successfully transformed this tactic, modernised it, and made it much more sophisticated and technologically advanced," he said.

Will Kingston-Cox, a specialist in Russia and the Ukraine war at the International Team for the Study of Security (ITSS) Verona, said that Moscow had previously used these tunnels to slip past Ukraine’s defences.

“One early example that I was thinking about was Avdiivka in January of 2024, where we saw Russian troops reaching the rear of the Ukrainian fortified position through what appears to have been a drainage conduit,” he said.

The Russian army has subsequently used this new tactic to retake Kursk from Ukrainian control, then in the Kupiansk region, where Ukrainians soldiers fought them for each foot of the pipeline tunneling through the earth.

Ryhor Nizhnikau, a senior research fellow at the Finnish Institute of International Affairs, said that these tactics were only made possible by the network of Soviet-era gas pipelines and other tunnels that once brought Russian natural gas across Ukraine into Europe.

“This is a new battlefield, but it’s much smaller in scale,” he said. “You can only operate in the network of pipelines that exists. But the fact is that we do see this network being used much more intensively over the past year.”

The map and the territory Nizhnikau said that these underground networks were also found in the Kharkiv, Luhansk and Donetsk regions, as well as in parts of Zaporizhzhia.

Gustav Gressel, a military analyst at Austria’s National Defence Academy, said that sewage and drainage pipes could also serve the same purpose in Ukraine’s cities. “In urban conglomerations, the wastewater system becomes another battlefield,” he said.

Largely built when eastern Ukraine was one of the industrial heartlands of the Soviet Union, these networks of pipelines are no secret to military planners in Kyiv and Moscow.

“Everyone knows how these pipelines were built in Soviet times,” Nizhnikau said. “So you have the map, and the Russians have the map.”Aliyev said that Ukrainian forces had initially tried to wait for Russian soldiers to surface from the tunnels in a grim game of whack-a-mole rather than take the fight underground.

“For a very long time they were actually making fun of Russians using pipelines, saying that it is so dangerous, so ineffective, and it never works,” he said.

But the Russian victories in Avdiivka and Kursk forced Kyiv to reconsider. In September 2025, Russian independent investigative media outlet iStories hammered the point home further, revealing how Moscow was stockpiling ammunition and supplies to use the gas pipeline in the Kupiansk region for a larger-scale offensive.

Out of sight Kingston-Cox said that the new underground front gave both sides ways to launch attacks and counter-attacks at a time where the mass proliferation of drones made above-ground assaults fraught.

“On open ground, a group can obviously be spotted well before it reaches its objective,” he said. “And we've seen countless cases where this has been the case with ... reconnaissance drones and also attack drones." Nizhnikau said that the constant threat of drones for tens of kilometres on either side of the front made even the narrow, potentially gas-choked tunnels a more compelling prospect.

“It's more predictable for people. I understand it's really horrible, but then, it’s better than being killed by a drone,” he said. “At least a foot soldier knows that his enemy is just ahead of him in the tunnel – and there is nothing coming from the skies when you don’t expect it.”While potentially perilous, Gressel stressed that the tunnels afforded soldiers rare protection from the drones that had become responsible for the bulk of the human casualties of the four-year war.

“Radio-controlled drones lose their signal at the entrance, and for fiber-optic drones the cable often snags in corners,” he said. “Nets, small wire or fishing lines can be spun around the entrance to prematurely detonate a drone.”But while the saturation of reconnaissance and attack drones was driving both sides to invest more into the fight for the tunnels criss-crossing Ukraine, Nizhnikau stressed that these tactics should be understood as “a support measure” to the broader fight. Aliyez agreed that this kind of tunnel warfare could not be replicated across the whole front.

“In a lot of places along the front line, there's just no such infrastructure to use in the first place,” he said.

The claustrophobic nature of these pipelines also makes it near impossible to use them to launch larger-scale offensives.

“A narrow pipe, for example, can deliver infantry past an obstacle – but then it would also have very limited capacity to support a larger force under pressure,” Kingston-Cox said. “If the defender is watching the opening and people are coming out a few at a time, this could become extremely vulnerable." Despite its limitations, he said, these high-risk tactics could be used to help “break local deadlocks”.

And until now, these disused pipelines have largely been used by Russian forces to push deeper into Ukraine. Through operations such as Veles, the Ukrainians are showing that they’re ready to take the fight to Moscow on any battlefield. This article has been adapted from the original in French.