Russia Sets Sights on Ukraine's 'Fortress Belt': ISW

Moscow reportedly has its sights on gaining control of another Ukrainian city, the southernmost point of Kyiv's "fortress belt."

A Ukrainian military analyst has asserted that the Russian military is aiming to put pressure on Kostyantynivka through its recent redeployment of additional forces to neighboring cities Toretsk and eastern Pokrovsk, according to the Institute for the Study of War (ISW).

Newsweek reached out to the Ministry of Defense of Ukraine and the Ministry of Defense of the Russian Federation for comment via email.

Two Russian Soldiers Preparing to Fire
Two Russian soldiers preparing to fire toward Ukrainian positions at an undisclosed location in Ukraine, photographed on February 8, 2025. Uncredited, Russian Defense Ministry Press Service/Associated Press

Why It Matters

The ISW posited that the Russian military "appears to be committing to a multi-year-long effort to seize Ukraine's 'fortress belt' in Donetsk Oblast, further underscoring Russia's Putin's apparent disinterest in a lasting and enduring peace in Ukraine." These efforts could affect upcoming peace negotiations between Kyiv and Moscow.

This campaign to seize cities in Ukraine's "fortress belt" may be in vain as the U.S. think tank said that due to persisting manpower shortages and increasing equipment losses, "it is unlikely that the Russian military can sustain a multi-year and multi-axis campaign against Ukraine's fortress belt alongside its other offensive operations in Ukraine."

What To Know

Ukraine's "fortress belt" is a 50-kilometer-long line (approximately 31 miles) along the cities Slovyansk, Kramatorsk, Druzhkivka, and Kostyantynivka that forms the line of Kyiv's defenses in Donetsk Oblast, in eastern Ukraine. As of April 2024, the cities along the "fortress belt" sat between 12 and 30 kilometers (7.5 to 18.6 miles) from the front line.

In a post on Telegram, Ukrainian military analyst Kostyantyn Mashovets wrote that Russia recently redeployed elements of the 20th Motorized Rifle Division's 242nd, 255th, and 33rd motorized rifle regiments and the 150th Motorized Rifle Division's 102nd and 103rd motorized rifle regiments and 163rd Tank Regiment to Toretsk and eastern Pokrovsk.

Mashovets theorized that the reason for the redeployments is to outflank "the tactical group of the Ukrainian Armed Forces, which is defending itself south of Konstantinovka, in the area between Alexandropol and Tarasovka" and "achieve its encirclement and defeat." He added that he believes this would ultimately lead to "a two-way breakthrough (from the southwest and southeast) to the Stepanovka - Berestok - Pleshcheyevka - Yablonovka area (8th Army, together with the 51st Army)" after which a "simultaneous assault on Konstantinovka will follow, both from this area and from the side of Chasov Yar (the 3rd Army + airborne forces will join in)."

As of February 16, the ISW assessed that Russian forces are "operating east of Pokrovsk near Vozdvyzhenka are roughly 22 kilometers south of Kostyantynivka at their closest point of advance and that Russian forces operating in Toretsk are roughly 11 kilometers from Kostyantynivka at their closest point of advance" and that they could "possibly reach the southern outskirts of Kostyantynivka in May 2025."

However, the Washington, D.C.-based think tank noted that while "Russian advances east and south Kostyantynivka would pressure the fortress belt," they are "unlikely to completely collapse and seize the fortress belt in 2025 or even 2026."

What People Are Saying

In a post on X, formerly known as Twitter, Iuliia Mendel, a former spokesperson for Ukrainian president Volodymyr Zelensky, wrote: "Russia may be shifting its offensive focus to Kostyantynivka, the southernmost stronghold of Ukraine's fortified defense line in Donetsk Oblast, in spring-summer 2025. In Dec-Jan, Russian forces pushed rapidly south and southwest of #Pokrovsk, but since Feb, their momentum has stalled, writes @TheStudyofWar. Now, a large-scale redeployment of Russian troops signals that Moscow's military command sees #Kostyantynivka as its next key target. #RussianAggression."

Giorgi Revishvili, a political analyst, wrote on X: "Pokrovsk: Limited Ukrainian Success. Russian attacks in the Pokrovsk area have slowed over the past two months. Instead of engaging in direct urban combat for Pokrovsk, Russian forces are attempting to bypass the city and cut off its supply lines. Their primary objective is to gain full control of key logistical routes to and from Pokrovsk, particularly the T0504 highway to the west and east of the city."

What Happens Next

It is unknown at this time how much Russia's efforts to seize cities along Ukraine's "fortress belt" will affect peace negotiations with Kyiv, and if Moscow's recent redeployments will delay the process.

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About the writer

Maya Mehrara is a News Reporter at Newsweek based in London, U.K.. Her focus is reporting on international news. She has covered Ukraine, Russia, immigration issues, and the revolution in Iran. Maya joined Newsweek in 2024 from the Londoners and had previously written for MyLondon, the Camden New Journal, BUST Magazine, and Washington Square News. She is a graduate of New York University and obtained her NCTJ at News Associates. Languages: English. You can get in touch with Maya by emailing m.mehrara@newsweek.com


Maya Mehrara is a News Reporter at Newsweek based in London, U.K.. Her focus is reporting on international news. She ... Read more