Institute for the Study of War@TheStudyofWar
MORE: ISW is no longer prepared to forecast when Russian forces might seize Donetsk, including the Fortress Belt, since the slowing rate of Russian advances and the challenging nature of the Ukrainian-held terrain in Donetsk makes it unclear that Russia is capable of seizing the territory at all. ⬇️
Russia’s exaggerated territorial ambitions and aggressive territorial demands run completely counter to battlefield reality. Anonymous sources in contact with Putin and additional sources familiar with the matter as well as a Ukrainian intelligence assessment shared with FT indicate that senior Russian commanders have convinced Putin that Russian forces could seize all of Donetsk and Luhansk oblasts by Fall 2026. ISW has observed evidence to assess that Russian forces have only advanced 349.89 square kilometers in Donetsk Oblast since the start of 2026, an advance rate of 2.63 square kilometers per day.
Strong Ukrainian fortifications, the area’s challenging human and physical geography, and Ukrainian counterattacks and mid-range strike campaign that are already inhibiting Russian offensive operations across the theater make the prospects for a Russian seizure of the rest of Donetsk dim.
Russian forces first infiltrated into Kostyantynivka (the Fortress Belt’s southernmost city) in October 2025 and have failed to make any significant tactical gains in the city over the last six months. Ukrainian counterattacks in southern Ukraine since early 2026 have also forced Russia to choose between defending against Ukrainian counterattacks and allocating manpower and resources to priority sectors of the frontline, including the Fortress Belt.
Ukraine’s recent successes are accomplishing tactical, operational, and strategic battlespace effects that undermine Putin’s narrative that the Ukrainian frontlines are on the verge of collapse. Two people involved in back-channel negotiations over ending the war told the FT that Putin’s ambitions are still to control all the Ukrainian territory between Russia and the Dnipro River, and possibly farther into Kyiv City and the port of Odesa, despite Russia’s stalling offensive. Putin’s thinking thus appears to be further and further removed from battlefield realities, likely resulting in the issuance of orders to the Russian military to make gains that it is not capable of making.