National Defense

Ukraine’s War Goes Underground As Troops Battle Inside Gas Pipelines

(Houses of the Oireachtas, CC via Wikimedia Commons)

Russian and Ukrainian soldiers are fighting a brutal underground war inside narrow Soviet-era gas pipelines, turning the battlefield beneath Ukraine into a deadly new front as drones make movement above ground increasingly dangerous.

Ukrainian forces have launched an underground counteroffensive near Kupiansk, reversing a Russian tactic that previously allowed Moscow’s troops to infiltrate behind enemy lines, according to Ukrainian President Volodymyr Zelenskyy. The operation has reportedly killed more than 100 Russian soldiers and resulted in dozens of prisoners, according to Ukraine’s Defense Ministry.

The fighting underground has become exceptionally dangerous. One video posted on Instagram by Ukraine’s 39th Brigade and Dark Navy Syndicate appears to show a heavily fortified position in a tunnel where a Ukrainian soldier is firing an M2 .50 caliber machine gun.

The position is so heavily fortified that the gunner cannot see what he is shooting at on the other side of the sandbags. He could be firing at enemy troops, or simply spraying his .50 at nothing.

“Drones and increasingly sophisticated surveillance techniques have forced both sides underground big time,” Matt Boyse, a senior fellow at the Hudson Institute, told the Daily Caller News Foundation. “While bunkers and other protective measures have been major fixtures of the war on both sides since the first Russian invasion in 2014, subterranean combat is a relatively new area, as Russia in particular has sought to avoid Ukrainian ‘kill zones.'”

“The Russians have used drainage tunnels in urban warfare and natural gas pipelines to try to infiltrate behind Ukrainian lines. The Ukrainians have fought back by flooding pipelines, mining or sealing them, but also in close-quarters combat,” Boyse added.

Another video, posted on X by Zelenskyy, shows what appears to be Russian prisoners of war being transported through the pipelines, wearing duct tape as makeshift blindfolds.

The mission, dubbed Operation Veles, involved Ukrainian troops advancing more than nine miles through underground pipelines beneath the northeastern Kharkiv region, according to the Ukrainian military.

Ukraine’s National Guard 2nd Khartiia Corps coordinated the underground assault with surface operations and drone strikes, seeking to cut off Russian infiltration routes near Kupiansk, according to the Ukrainian military.

“Modern Firepower incentivizes fortification,” Barry R. Posen, Ford International Professor of Political Science and former director of the Security Studies Program at the Massachusetts Institute of Technology (MIT), told the DCNF. “Urban areas are sought out because they are pre-built fortifications, which can easily be improved with clever combat engineering. Tunneling is a part of this, as is the exploitation of sewage systems, etc. One does not wish to be seen, and one wishes to evade the destructive power of modern weaponry … Drones have added an extra component to the problem from both a surveillance and a survivability point of view.”

The 2nd Corps of the National Guard of Ukraine uploaded a video on X summarizing the operation and showing off combat footage.

Russian troops had previously exploited the sprawling pipeline network to move beneath Ukrainian defenses, establish fortified positions and emerge behind Ukrainian lines without exposing themselves to aerial surveillance, according to The Wall Street Journal.

“Underground warfare also carries considerable risks,” David Cattler, a senior fellow with the Transatlantic Defense and Security Program at the Center for European Policy Analysis (CEPA), told the DCNF. “Confined spaces restrict maneuver. Close-quarters engagements are exceptionally dangerous, and ventilation, navigation, structural stability and casualty evacuation present serious challenges. Communications are particularly problematic, complicating command and control and situational awareness. Forces may gain concealment from enemy surveillance while sacrificing much of their own ability to understand and control the fight.”

Some pipelines measure just three to four feet in diameter, forcing soldiers to crawl or maneuver through extremely confined spaces. Russian troops reportedly constructed sandbag fortifications, machine-gun positions and underground living quarters, according to the Journal.

Movement in the tunnels has become quite advanced, with small makeshift electric trains pulling troops back and forth, according to a video posted by the Journal on X.

Ukrainian soldiers described fighting at extremely close range, sometimes separated from Russian troops by only a few feet. The underground passages also contain gas fumes, human remains and other hazardous conditions, the Journal reported, citing Ukrainian military personnel.

“The main tactical advantage of moving underground is the ability to evade the pervasive aerial observation and attacks by drones, which in turn allows to preserve the element of surprise,” Federico Borsari, a nonresident fellow with the Transatlantic Defense and Security Program at CEPA, told the DCNF. “Pipelines and tunnels can provide concealed infiltration routes, enable troops to bypass exposed terrain, and potentially threaten an adversary’s rear areas. They also offer relatively protected routes for moving personnel and limited supplies. I think that what makes the Ukrainian case distinctive is the combination of a sort of underground maneuver with coordinated operations above and below the surface.”

Ukraine has deployed explosive-carrying unmanned ground vehicles to destroy Russian barricades and remotely operated machine guns to engage enemy positions. However, debris and bodies inside the pipelines have sometimes obstructed the robots, according to the Journal.

The fighting represents an escalation of underground tactics Russia has employed for years.

“This appears to be a more sophisticated and long-term use of these pipelines,” Col. Drew Craig, the principal military engineering staff officer at NATO’s Allied Rapid Reaction Corps and a specialist in subterranean warfare, told the DCNF. “The tactical advantages are best framed as the ability to operate and manoeuvre, albeit along highly confined routes, without the constant risk of observation, detection and then attack from drones.”

Russian troops previously used underground infrastructure during operations around Avdiivka in 2024 and Sudzha in Russia’s Kursk region in 2025, according to military researchers at West Point’s Modern War Institute.

Near Kupiansk, Moscow’s forces exploited pipelines running beneath the Oskil River to bypass Ukrainian defenses and establish positions in the city’s northern districts, according to the Hudson Institute.

Another video uploaded by Ukraine’s Ministry of Defense on X shows a visual representation of the pipeline, showcasing how far behind enemy lines these tunnels allow Ukrainian and Russian troops to travel.

Zelenskyy praised Operation Veles on Tuesday, saying his troops had turned Russia’s underground tactics against Moscow.

The operation has eliminated more than 100 Russian soldiers and captured more than 30 others, Zelenskyy claimed, according to the Ukrainian presidency. The casualty figures have not been independently verified.

The operation has reportedly prevented Russia from reinforcing its positions in northern Kupiansk, although Russian personnel remain dispersed throughout the area, according to the Institute for the Study of War.

Underground combat is hardly unprecedented in modern warfare, with Israeli forces spending years battling Hamas militants through an extensive tunnel network beneath the Gaza Strip. The Israel Defense Forces. (IDF) reported discovering more than 800 tunnel shafts and destroying approximately 500 by December 2023.

Israeli troops have also engaged Hamas fighters in close-quarters combat inside fortified underground passages containing explosives, blast-resistant doors and command facilities. In January 2024, the IDF’s 98th Division raided a tunnel complex approximately 65 feet underground in Khan Younis, killing militants inside before destroying the network, according to the IDF.

An Oct. 15 video uploaded by the IDF on X shows how the HAMAS tunnels have been reinforced with concrete to prevent cave-ins.

Hamas has used these underground networks for troop movements, weapons storage, command operations and attacks against Israeli forces. Israeli combat engineers have subsequently worked to dismantle the infrastructure, including a tunnel system stretching more than 2.5 miles near the Erez crossing, according to the IDF.

“Underground warfare in Ukraine is a natural progression of the nature of the war,” Matthew Wallin, chief executive officer of the American Security Project, told the DCNF. “In World War One, frustrated by the carnage of trench warfare, underground miners dug long tunnels to bypass enemy trenches or place mines. The enemy would employ counter-mining teams to intercept or collapse tunnels. In the Battle of Messines, the British notably set off a series of explosive-packed mines under the German lines that together represented the biggest conventional explosion in history at the time. Tunnels were also common in Vietnam.”

Tunnel warfare dates back centuries, with Ottoman forces employing underground mining operations during the Great Siege of Malta in 1565. Ottoman engineers dug beneath the fortified city of Birgu in attempts to destroy defensive walls, while the Knights of St. John developed countermining tactics to detect and intercept enemy tunnels, according to the National Trust of Malta.

The tactic resurfaced during the American Civil War, most famously at the Battle of the Crater in Petersburg, Virginia, on July 30, 1864. Union soldiers excavated a roughly 500-foot tunnel beneath Confederate fortifications and detonated 8,000 pounds of gunpowder, creating an enormous crater before their subsequent assault collapsed into a bloody defeat as Union troops rushed into the crater where they became trapped, according to the National Park Service.

Underground warfare became particularly destructive during World War I, when British and German engineers dug extensive tunnel networks beneath opposing trenches to plant explosives and destroy enemy positions. On July 1, 1916, British troops detonated approximately 60,000 pounds of explosives beneath German defenses during the Battle of the Somme, creating the massive Lochnagar Crater, approximately 330 feet wide and 70 feet deep, according to the Lochnagar Crater memorial.

The underground fighting also raises significant questions about the future of warfare.

“I’m not as concerned about training for subterranean operations as I am about operating on a battlefield full of drones,” Wallin told the DCNF. “Today’s U.S. and NATO forces are not accustomed to fighting in environments where battlefield maneuvers are so easily observed, severely limiting the element of surprise. I think that will affect above-ground warfare more significantly than anything happening underground.”

John Spencer and Craig, military researchers specializing in subterranean warfare, argued in August that increasingly sophisticated drones and surveillance systems are forcing both armies underground. Ukraine has expanded its subterranean infrastructure to include command centers, hospitals, military manufacturing facilities and logistical networks, according to their analysis published by the Modern War Institute.

The researchers warned that NATO must adapt its training, military engineering capabilities and operational doctrine to account for the growing importance of underground warfare, according to the Modern War Institute.

“Much like drones and other major evolutions in warfare, it’s not a silver bullet or shield and has to be used on conjunction with the other tools and methods of war,” Craig told the DCNF. “We must learn and we must look to evolve, as fast as possible. We must consider how we will look to detect and deny these routes and spaces or indeed learn to repurpose/engineer existing underground infrastructure or create new routes and spaces to meet our military needs.”