Moscow’s Strategic Shift: Targeting Kostyantynivka in Ukraine’s "Fortress Belt"

A New Focus in the Conflict: Kostyantynivka

Moscow appears to be setting its sights on capturing another key Ukrainian city, Kostyantynivka, located in the southernmost part of Ukraine’s "fortress belt" in Donetsk Oblast. According to a Ukrainian military analyst cited by the Institute for the Study of War (ISW), Russia has recently redeployed additional forces to the neighboring cities of Toretsk and eastern Pokrovsk. This move is seen as an attempt to exert pressure on Kostyantynivka and potentially encircle Ukrainian forces defending the area. The ISW suggests that Russia is embarking on a multi-year effort to seize Ukraine’s "fortress belt," a defensive line spanning 50 kilometers and including cities like Slovyansk, Kramatorsk, Druzhkivka, and Kostyantynivka. This strategy underscores Moscow’s apparent disinterest in pursuing a lasting peace in Ukraine, as it continues to escalate its military campaign.

The implications of this strategy could extend beyond the battlefield, potentially impacting upcoming peace negotiations between Kyiv and Moscow. Ukraine’s "fortress belt" is a critical line of defense in Donetsk Oblast, with cities currently situated 12 to 30 kilometers from the front lines. Russian forces operating near Pokrovsk and Toretsk are within striking distance of Kostyantynivka, with some units as close as 11 kilometers from the city. Analysts predict that Russian advances could reach the outskirts of Kostyantynivka by May 2025. However, the ISW doubts that Russia has the manpower or resources to sustain a multi-year campaign against the "fortress belt," given its ongoing manpower shortages and equipment losses.

The "Fortress Belt" and Its Strategic Importance

Ukraine’s "fortress belt" is a 50-kilometer-long defensive line in Donetsk Oblast, designed to protect key cities like Slovyansk, Kramatorsk, Druzhkivka, and Kostyantynivka. As of April 2024, these cities are positioned 12 to 30 kilometers from the front lines, forming a critical barrier against Russian advances. Kostyantynivka, in particular, is the southernmost point of this defensive line, making it a strategic target for Russian forces aiming to break through Ukraine’s defenses.

The recent redeployment of Russian troops to Toretsk and eastern Pokrovsk has raised concerns among Ukrainian analysts. Kostyantyn Mashovets, a Ukrainian military analyst, noted that Russian forces have moved elements of the 20th and 150th Motorized Rifle Divisions to these areas. He believes this maneuver is an attempt to outflank Ukrainian forces defending south of Konstantinovka, with the goal of encircling and defeating them. Mashovets predicts that a successful Russian advance could lead to a two-way breakthrough into the Stepanovka-Berestok-Pleshcheyevka-Yablonovka area, followed by a simultaneous assault on Konstantinovka from multiple directions.

Military Movements and Strategic Objectives

The ISW has assessed that Russian forces near Pokrovsk and Toretsk are positioned to exert significant pressure on Kostyantynivka. As of February 16, Russian units operating east of Pokrovsk were approximately 22 kilometers south of the city, while those in Toretsk were just 11 kilometers away. Analysts warn that these forces could reach the southern outskirts of Kostyantynivka by May 2025, potentially threatening the city’s defenses.

However, the ISW remains skeptical about Russia’s ability to achieve a decisive victory in the near term. Despite its advances, Russia faces significant challenges, including manpower shortages and equipment losses, which make it unlikely to sustain a multi-year campaign against the "fortress belt." The think tank also notes that while Russian advances could pressure Ukraine’s defenses, they are unlikely to result in the complete collapse of the "fortress belt" in 2025 or 2026.

Reactions from Analysts and Officials

Iuliia Mendel, a former spokesperson for Ukrainian President Volodymyr Zelensky, highlighted the significance of Kostyantynivka on the social media platform X (formerly Twitter). She noted that Russia may be shifting its offensive focus to the city in spring-summer 2025, following a period of stalled momentum near Pokrovsk. Mendel emphasized that the large-scale redeployment of Russian troops signals Moscow’s intent to make Kostyantynivka a key target.

Giorgi Revishvili, a political analyst, also commented on the situation in Pokrovsk, where Russian attacks have slowed in recent months. Instead of engaging in direct urban combat, Russian forces are attempting to bypass the city and cut off its supply lines, particularly the T0504 highway. Revishvili described this as an effort to gain control of key logistical routes, which could have implications for Ukraine’s ability to maintain its defenses in the region.

What’s Next: Implications for Peace Talks and the War Ahead

The implications of Russia’s campaign to seize cities along Ukraine’s "fortress belt" remain uncertain. It is unclear how these developments will impact peace negotiations between Kyiv and Moscow or whether the recent redeployments will delay the process. Some analysts speculate that Russia’s continued military pressure could harden Ukraine’s position in negotiations, making a diplomatic resolution more challenging to achieve.

Meanwhile, the battle for Kostyantynivka and the broader "fortress belt" is likely to remain a focal point of the conflict in the coming months. Ukraine’s ability to hold its defensive lines will depend on its capacity to respond to Russian maneuvers and maintain its military resources. At the same time, Russia’s ability to sustain its campaign will hinge on its ability to address its manpower and equipment shortages, which have already begun to strain its military efforts. As the situation continues to unfold, the world will be watching closely to see how these developments shape the trajectory of the war and the prospects for peace.