Ukraine Keeps Downing Russian Drones, but Price Tag Is High

Exploding drones are lumbering and noisy and relatively easy to shoot from the sky and, over the New Year’s weekend, Ukraine says, its military downed every single one of about 80 that Russia sent the country’s way.

“Such results have never been achieved before,” a Ukrainian air force spokesman said on Tuesday.

But some military experts wonder if the successes are sustainable.

Ukraine is getting more and more skilled at knocking down drones, but there is a growing imbalance: Many of its defensive weapons like surface-to-air missiles cost far more than the drones do. And that, some military experts say, may favor Moscow over the long haul.

Artem Starosiek, the head of Molfar, a Ukrainian consultancy that supports the country’s war effort, estimated that it costs up to seven times more to down a drone with a missile than it does to launch one. That is an equation that the Kremlin may be banking on, some analysts say.

President Volodymyr Zelensky of Ukraine, in an overnight speech, warned that Russia was betting on the “exhaustion of our people, our air defense, our energy sector.”

Ukraine has vowed not to be cowed by the aerial assault, but the attacks have been unrelenting.

Molfar said its group estimated that, since September, Russia had launched around 600 drones at Ukraine. The campaign, targeted at infrastructure and accompanied by numerous missile strikes, has knocked out power, heating and water across Ukraine just as the country’s harsh winter has started to bite, compounding the misery of a Russian invasion that is nearing its first anniversary.

The Iranian-made Shahed-136 drones that Moscow has increasingly been relying on since October are relatively uncomplicated devices and fairly cheap, while the array of weapons used to shoot them out of the sky can be much pricier, according to experts. The self-destructing drones can cost as little as $20,000 to produce, while the cost of firing a surface-to-air missile can range from $140,000 for a Soviet-era S-300 to $500,000 for a missile from an American NASAMS.

Since the war began in February, both sides have used drones not just for reconnaissance but also for attacks. It is the first time the devices have been so widely deployed in a European war. Some military experts view Ukraine as a testing ground for state-of-the-art weapons and information systems that may foreshadow the shape of warfare for generations to come.

The military authorities in Kyiv have said little about the details of their air defenses — in keeping with the operational secrecy that has shrouded much of their war planning — or about the cost, making analysis difficult.

But it is known that while Ukraine’s forces have enjoyed some success against drones using antiaircraft guns and even small-arms fire, that has changed as the Russians have taken to launching assaults at night. Now Kyiv is also relying heavily on missiles fired from warplanes and the ground. Over the weekend, officials said, Ukraine employed surface-to-air missiles fired from NASAMS — for National Advanced Surface-to-Air Missile System — multiple times to counter drones.

Michael Kofman, an expert on the Russian military at the CNA research institute, said that Ukrainians were using “a zoo of different air defense systems” to combat the threat, including Soviet-era and NATO missile systems, each with its own cost profile.

Some of Ukraine’s antiaircraft guns, like the Gepard 2 radar-directed mobile gun system, are inexpensive in comparison with other Soviet-era and European defense systems being deployed. But some of the American-made interceptor missiles are fairly expensive compared with drones.

Even so, evaluating the wisdom of downing drones with missiles is not always straightforward.

George Barros, an analyst at the Institute for the Study of War, said he suspected that Ukraine was deploying more complex and expensive air defense systems to protect sensitive and critical infrastructure.

It costs far less, for example, to shoot down a drone than to repair a destroyed power station, Mr. Starosiek noted. And then there is the human factor.

“People are still alive,” he said.

Mathieu Boulegue, a consulting fellow with the Russia and Eurasia Program at Chatham House, a London-based research organization, said that Ukraine currently had enough air defense weapons and ammunition to combat the threat of Russian drones.

“The cost is irrelevant as long as the West keeps providing military assistance to Ukraine,” Mr. Boulegue said. “The problem for Kyiv is the moment they don’t have enough stock of ammunition in their air-defense chain to shoot down these drones.”

Aware of the risk that Western allies may grow weary of the cost of supporting Ukraine’s defense — a concern heightened by the transfer of leadership in the U.S. House of Representatives to the Republicans — Ukrainian officials have warned that Russian tactics are changing.

The White House has said that it is aware of reports that the Kremlin and Tehran are seeking to establish a joint production line for drones in Russia. Over the long term, Mr. Boulegue said, that would allow Moscow to deploy still more drones in attacks.

“That is going to put more stress on Ukraine’s air defense system,” he said.

That helps explain why Ukraine has adapted its own tactics, in part by conducting strikes on bases deep inside Russian territory. The goal, Mr. Boulegue said, is “to increase deterrence, which they hope will place less stress on air defense.”

For now, Moscow has changed how it using the drones it already has in hand.

Russian forces have increasingly been launching their explosive drones at night and low along the Dnipro River, making it harder for Ukraine to detect them, according to Yurii Ihnat, the spokesman for the Ukrainian air force, who was speaking on Ukrainian radio.

“The radar antenna that detects the target will not see it if the target is flying below the level of the antenna,” he said.

Andrew E. Kramer, Julian E. Barnes, John Ismay and Shashank Bengali contributed reporting.