UNDISCLOSED LOCATION, Ukraine - Inside a concealed warehouse at night, masked operatives from Ukraine's GUR military intelligence unit drill and assemble a series of 15-foot aircraft. These Liutyi long-range kamikaze drones carry up to 150 pounds of explosives and can cover nearly 1,300 miles before striking targets deep in Russia.

"They represent our strongest asset in this conflict," notes a Ukrainian commander known by the call sign Vector while touching the wing of one drone. He directs operations focused on deep strikes well beyond Russian front lines.

What started in early 2024 with limited numbers has grown into a major effort. Ukrainian forces under President Volodymyr Zelenskyy now dispatch 200 to 300 drones nightly toward sites across Russian territory.

On Thursday, Ukraine carried out its biggest such assault yet, hitting an oil refinery close to Moscow. Blasts produced thick black smoke over suburban areas and halted flights at four airports for several hours. Russian authorities claimed to have intercepted hundreds of drones over Moscow and additional cities.

A team from the Axel Springer Global Reporters Network, including Business Insider, received access to watch one evening of preparations this month. Rules protected the unit: no mobile phones, no filming of intelligence staff faces, and altered voices for any recordings.

Officials described the strikes as using a hard-to-defeat mix of explosive long-range kamikaze drones, decoys to mislead defenses, and faster missile-style drones. Main goals include military sites and oil infrastructure vital to Russia's war efforts and funding.

"Russians once saw this as a special military operation. They now recognize it as full war," Vector said. The signal to Moscow is clear: "This conflict has arrived at your doorsteps too." He hopes this will push Russia toward ending the fighting.

Zelenskyy views the drone effort as key to tilting the war. He issued an open letter to Putin calling for direct peace talks and pointed to the drone strikes, such as one on St. Petersburg on June 3 that disrupted an economic summit with visible smoke plumes.

"As you know well, that range does not mark the edge of our reach," Zelenskyy wrote, noting effects like fuel shortages, higher costs, and fear for everyday Russians.

"They dislike our drones and missiles," he added, recently calling the operations "long-range sanctions" in a light tone.

The campaign already shows clear economic effects in Russia. At the St. Petersburg summit, Deputy Prime Minister Alexander Novak admitted oil output has fallen since January, blaming unscheduled refinery maintenance - code for damage from Ukrainian drones. Several major facilities in central Russia have cut production or stopped after hits.

Ben Hodges, former head of US Army Europe, notes Russia's historic strength in vast territory now works against it.

"Thanks to Ukraine's long-range precision strikes, what was once an advantage has become a serious weakness," he said. "They cannot shield every refinery, shipyard, or factory - all are now within reach, even in Siberia."

Analyst Franz-Stefan Gady, who visits Ukrainian units, says Russia faces a built-in drawback in drone conflicts due to its size.

"The cost imbalance now favors the attacker over the defender," Gady noted.

Russia's economy is far from breaking. Yet refinery strikes now deliver more than dramatic fireballs and smoke. They create real interruptions in parts of the energy sector.

Industry figures show repeated hits have at times affected a notable portion of Russia's oil export capacity this year, leading to schedule changes and supply shifts. Impacts appear outside the plants themselves.

"History shows war tests both will and logistics. Ukrainians are targeting Russian logistics hard," Hodges said.

Russia has gained from recent global events. Conflict involving the United States, Israel, and Iran has lifted oil prices, giving Moscow an unexpected revenue lift. Higher state oil and gas income, about one-fifth of the budget, has eased some pressure from sanctions and strikes.

'We know how they move'

Just before midnight in the warehouse, GUR technicians secure the last parts on the long-range drones.

Some models now reach 2,000 miles and carry over 500 pounds, Vector said.

"Rest assured we can hit any spot up to the Urals," he added, referring to the range marking eastern European Russia and the start of Siberia. "With some fortune, maybe farther."

Each drone costs around $230,000, varying by setup.

Russia struggles to halt the waves because Ukraine keeps changing tactics. Nightly, small teams spread out, often in eastern Ukraine, launching from varied spots.

"If Russians take out some sites or drones, we still have 10 or 20 more ready. That matters greatly," Vector explained.

This mirrors guerrilla methods suited to Ukraine's asymmetric approach and proves tough to stop.

Nearby sit smaller decoy drones without explosives. Launched first, they distract air defenses. Ukraine also uses faster jet-powered missile drones in combined attacks.

Technicians ready several alongside the larger ones. They name the jet model Peklo, meaning Hell in Ukrainian.

"It is highly accurate and swift. A special navigation system and antenna allow precise strikes on small targets," said a technician with call sign Logist.

Austrian colonel and analyst Markus Reisner thinks Russian defenses face growing strain from the volume and mix of attacks. AI-guided drones resist jamming, reducing a key Russian defense tool.

The data focus shows in a side room where pilots plan routes using real-time screens for weather, Russian positions, and flight details.

"Daily and hourly, we track air-defense and electronic warfare movements. Each night brings new routes. None repeat," Vector said.

Prisma, the AI software central to the effort, merges live data into an updated picture. Lessons from many missions form a key asset.

"We review routes across years and identify the best corridors," he noted.

Drones have reached even the defended Moscow area. Asked when he last planned a Moscow strike, Vector laughed but declined to comment publicly.

Ibrahim Naber serves as a foreign correspondent covering Ukraine since 2022. In October 2025, he and his team sustained injuries from a Russian Lancet drone strike in Dnipro. He earned the George Weidenfeld Prize in 2025 for conflict reporting and completed his dissertation at King's College London on the psychology of modern drone warfare.

This account first appeared on POLITICO and comes via the Axel Springer Global Reporters Network, which pools resources across newsrooms for major reporting, investigations, interviews, opinions, and analysis. Journalists from POLITICO, Business Insider, WELT, BILD, Onet, and Fakt collaborate on stories for a global audience.