For weeks, the Russian military has been flying explosive-laden "Iranian drones" into critical Ukrainian infrastructure facilities and residential areas. Most of the drones are now intercepted by air defenses, however, according to the British Ministry of Defense, a third still reach their targets.

Ukraine's prime minister, Denys Shmyhal, has said the Russians use "20 to 30 Iranian 'kamikaze' drones' against us every day." 

"They want to take away our population's electricity, water and heating in the winter," Shmyhal told Germany's Frankfurter Allgemeine Zeitung on Saturday. The premier warned numbers of Ukrainian refugees would increase drastically if Russian forces continue to destroy civilian infrastructure.

The German IRIS-T air defense system has already saved "many, many lives," especially in the Kyiv area, Shmyhal said. But Ukraine is impatiently waiting for the next ammunition delivery and the next system.

Iran, Russia deny drone cooperation

Both Russia and Iran vehemently oppose any efforts to clarify the origin of the drones. Russia's UN Ambassador Vassily Nebenzia has rejected a demand last week by the Untied States and European countries for a UN investigation into the use of "Iranian drones."

Nebenzia claimed that such an investigation would violate the UN charter and would seriously damage relations between Russia and the UN. Iran has made similar statements.

Markus Kaim, a senior fellow at German Institute for International and Security Affairs in Berlin, told DW that Iran does not want to jeopardize ongoing talks with Europeans on restarting the nuclear deal, and will continue to deny the delivery and use of its drones in Ukraine.

As long as the origin of the drones can be put in doubt, it is still possible to continue negotiations on the nuclear agreement. An admission by Tehran, on the other hand, would make it very difficult for the Europeans to continue negotiations, Kaim said.

Evidence of Iranian drones in Ukraine

Despite Russian and Iranian denials, there is "striking" evidence that Iranian drones are being used in Ukraine, according to Kaim. This includes video footage presented by Ukrainians of drones in flight and wrecked remains found in rubble after attacks.

"In my estimation, there can be little doubt about this. Nor do I know of any serious expert who doubts that there have been arms deliveries [from Iran to Russia]," said Kaim.

Military expert Markus Reisner, a former director at the Austrian armed forces' Theresia Military Academy, told DW that massive movements of Russian aircraft back and forth to Iran are a clear indicator of the transport of large quantities of material.

Reisner added the design of drones that have been found "strongly suggests an Iranian model." The military expert said the drones are being deployed amid indications that Russia's arsenal is running short of more conventional aerial weaponry.

What drones are attacking Ukraine?

According to Reisner, the two types of Iranian drones likely used in Ukraine include the models Mohajer-6 and the Shahed-136.

The Mohaer-6 can reconnoiter and monitor a target. Like other drones of this type, it plays a major role in reconnaissance of targets for artillery, he said.

"But it can also be equipped with air-to-surface missiles, so it can also engage targets after it has reconnoitered them."

The Shahed-136, on the other hand, is a classic "kamikaze" drone. It is guided by a GPS system that leads it precisely to its destination with constant course correction.

But the key thing, said Reisner, is that this type of drone is usually not used in isolation. "Rather, it usually flies in a swarm of ten to 15 other drones. This overloads the Ukrainian defense systems."

While the systems do shoot down some of the drones, out of 15, some still make it to the target, he added.

The Russians then fire cruise missiles, as Ukrainian air defenses are vulnerable because new air defense missiles cannot be reloaded so quickly. Ukraine's systems are also exhausted after eight months, despite military support, the expert said.

"The drones are comparatively small. But conventional Ukrainian air defenses are usually programmed for much larger objects, such as airplanes and helicopters," said Reisner. "That's why you either have to upgrade them or rely on the modern systems that are now being delivered to Ukraine," which can intercept small targets.

Russia's long-term strategy

Despite the recent attacks, Ukraine remains optimistic about its drone defense .

"Of course, we do not have the technical capabilities to eliminate 100% of Russian missiles and combat drones," President Volodymyr Zelenskyy said in a recent video message.

However, Zelenskyy said he was sure that this would be achieved gradually with the help of international partners. "Already we are shooting down a large part of cruise missiles and drones."

Reisner said that although these kinds of statements are "legitimate," they are also part of psychological warfare, and should be taken with a grain of salt.

"You also have to see that the Russian missiles work very precisely. That 40% of Ukraine's infrastructure has been hit speaks to the tremendous precision of Russian attacks," said Reisner. 

"Ukraine's air defenses have taken heavy hits over the past eight months. That is now making itself felt. It is true that the Russians do not have air superiority and cannot fly planes over Ukraine. But they can attack targets wherever they want," he said, adding that this can be "strategically fatal" for the Ukrainians.

"The Ukrainian army is advancing in the south and east of the country. But in the hinterland, the infrastructure is being hit. In other words, people are in for a very hard winter. That could then lead to further civilian movements toward the west and lead to social discontent there. That's what Russia is counting on."

This article was translated from German.