Ukraine is stepping up its drone war against Russia, and now it's Moscow's turn to reassemble decades-old air-defense weapons

• Ukraine has stepped up its campaign of drone attacks on targets inside Russia, including in Moscow.
• In response, Russia appears to be copying WWII-style "flak towers" to augment its air defenses.

Desperate to stop Ukrainian drone strikes on Moscow and other targets inside Russia, Russian air-defense forces are resurrecting a World War II-era system: towers with guns.

Russia is building air-defense towers that some observers liken to the "flak towers" used by Nazi Germany. These "flaktürme" were huge concrete structures up to 230 feet — or 21 stories — high and studded with antiaircraft guns to protect German cities from Allied bombers.

The towers that have been built outside Moscow aren't quite as grand. They appear to be elevated structures with Pantsir mobile air-defense systems placed on top. Judging by photographs, some towers appear to be at least three stories high. With no visible ramp, the truck-mounted Pantsir was presumably put in place by crane or heavy-lift helicopter.

Other towers are lower, more like elevated ramps perhaps 20 feet high or so. Pantsirs have already been deployed atop government buildings in Moscow, but the new structures appear to be purpose-built for antiaircraft batteries.

The move comes after multiple attacks by Ukrainian drones that have embarrassed the Kremlin and the Russian military. Britain's BBC estimates there have been more than 190 drone strikes on Russia and Russian-occupied Crimea. While the targets have been mostly in western Russia near the Ukrainian border, attacks have ranged as far as St. Petersburg, with more than a dozen strikes on Moscow.

The physical impact of these Ukrainian attacks includes the destruction of a few Russian aircraft as well as damaging buildings and industrial sites, such as oil refineries. It's a pinprick compared with the devastation of Ukrainian infrastructure by Russian drone strikes, but the very fact that the Russian homeland is under attack undermines an authoritarian regime like that of Vladimir Putin, whose claim to power is that he can protect Russians from alleged enemies such as Ukraine and NATO.

The air-defense towers are not the first decades-old weapon to be used during the war in Ukraine. Despite the fanfare around innovative weaponry, both sides have relied on well-established hardware, especially artillery. Russia and Ukraine have both pressed decades-old flak guns into new service against low-flying missiles and drones.

The question for Russia is how much protection its new air-defense structures can provide. Higher elevation should extend the detection range and field of fire of the Pantsir, a three-vehicle system that includes radar, medium-range surface-to-air missiles, and twin 30-mm antiaircraft guns.

Still, given the vastness of Russia, these towers can only provide point defense for selected sites such as airbases and major cities.

But there may be a psychological benefit in creating a visible reminder to the Russian public that their government is protecting them. In 1940, Hitler demanded flak towers after British bombers conducted a small raid on Berlin. With his taste for grandiose architecture, Hitler conceived of structures that looked like medieval castles.

These structures sprouted in cities across German territory, including clusters of two to three towers in Berlin, Hamburg, and Vienna. They were armed with dozens of antiaircraft guns, including eight 128-mm cannons on the roof, that could hit planes at 50,000 feet. These big guns were supplemented by batteries of 20-mm rapid-fire cannons effective against low-flying aircraft.

Though the towers were tall enough to have a clear field of fire in urban areas, it's not clear how effective they were compared to regular air-defense sites. With concrete walls up to 11 feet thick and impervious to Allied bombs, however, they became attractive as air-raid shelters.

As German cities were pounded around the clock by Allied bombers, the flaktürme housed up to 30,000 people. They also served as air-defense headquarters, hospitals, and even repositories to protect artwork.

Yet there isn't that much resemblance between German flak towers and Russia's new air-defense structures, according to Edward Westermann, author of "Flak: German Anti-Aircraft Defenses 1941-1945."

"They are not the same as the current Russian use of rooftop systems, or systems around Moscow that are built on ramps," Westermann told Insider. "The Russian use of these systems appears to be more utilitarian than strategic, and their use does not appear to have much tactical or operational value besides possibly having a clearer or higher engagement zone in built-up urban areas."

Most of the German flak towers were destroyed after 1945, though a few remain today as tourist attractions — or because they're simply too difficult to blow up. Time will tell whether today's flak towers will become a permanent part of the Moscow skyline.

Michael Peck is a defense writer whose work has appeared in Forbes, Defense News, Foreign Policy magazine, and other publications. He holds a master's in political science. Follow him on Twitter and LinkedIn.