Ukraine's Operation Veles

Underground tunnel warfare in Ukraine has taken a new turn: Kyiv in October launched Operation Veles, sending specially trained and equipped soldiers through a disused gas pipeline in the Kupiansk region to confront Russian troops. President Volodymyr Zelensky last week described the operation as a "great success".

The soldiers advanced 15 kilometres along a pipe with a diameter of just 1.2 metres, securing the tunnel's entry. The pipeline passes beneath the Oskil River and into Kupiansk, a frontline city Russian forces have been fighting to capture.

Zelensky said the troops eliminated around a hundred Russian soldiers and took more than 30 prisoners in the underground fighting, and that Ukraine had upgraded the method itself:

A tactic Russia pioneered

The pipeline has been used against Ukraine before. Russian forces have employed underground pipeline tactics for more than two years to slip past Ukrainian lines, and until now the disused pipes have largely served Russian advances deeper into Ukrainian territory.

Will Kingston-Cox of ITSS Verona pointed to Avdiivka in January 2024 as an early example, when Russian troops reached the rear of Ukrainian defences through a drainage conduit. Russia then used the same approach to retake Kursk from Ukrainian control, and later in the Kupiansk region.

By September 2025, the Russian independent investigative outlet iStories reported that Moscow was stockpiling ammunition and supplies to use the Kupiansk pipeline for a larger offensive. Huseyn Aliyev of the University of Glasgow said Russia started the underground tactics and that this was the first known instance of Ukrainians adopting them. He noted that Ukrainian forces had long mocked the Russian pipeline tactic and initially preferred to wait for Russian soldiers to surface rather than fight them underground.

Why drones push fighting underground

The shift underground is closely tied to drone warfare in Ukraine. Kingston-Cox said the underground front offers attack options precisely because drones make above-ground movement easy to spot: "On open ground, a group can obviously be spotted well before it reaches its objective".

According to Gustav Gressel of Austria's National Defence Academy, drones have become responsible for the bulk of the human casualties in the four-year war. Yet the tunnels also resist them. Gressel explained that "Radio-controlled drones lose their signal at the entrance, and for fiber-optic drones the cable often snags in corners", while nets and wires can detonate drones prematurely.

For foot soldiers, Ryhor Nizhnikau of the Finnish Institute of International Affairs said, the drone threat hanging over tens of kilometres makes the narrow, potentially gas-choked tunnels the comparatively safer choice: "it's better than being killed by a drone".

Limits of the underground front

The tactic has hard constraints. Nizhnikau stressed that it depends on Soviet-era gas pipelines that once carried Russian gas across Ukraine into Europe: "You can only operate in the network of pipelines that exists." Similar underground networks are also found in the Kharkiv, Luhansk and Donetsk regions and in parts of Zaporizhzhia. Because the Soviet-era construction is known to both sides' military planners, "So you have the map, and the Russians have the map."

Urban infrastructure could extend the underground front in places. Gressel noted that sewage and drainage pipes could serve the same role: "In urban conglomerations, the wastewater system becomes another battlefield".

Analysts see the tactic as bounded. Nizhnikau described tunnel operations as a support measure, and Aliyev said they cannot be replicated along the whole front because much of it simply lacks the infrastructure. Kingston-Cox added that narrow pipes can move infantry past an obstacle but cannot sustain a larger force, and that soldiers exiting the pipe are exposed if defenders are watching the opening. Used well, he said, these high-risk tactics can help "break local deadlocks".