Writing for the Kyiv Independent, Francis Farrell notes that despite the war's fading presence in the international spotlight, the daily battles in Ukraine's east remain as intense as ever. Net Russian territorial gains have largely flatlined despite consistently heavy casualties, and Ukrainian forces have carried out two successful counterattacking operations of strategic importance.
Russia's main goal continues to be the capture of the remainder of Donetsk Oblast. Russian forces have inched closer to the last remaining Ukrainian cities in the region, while Ukraine has sought to create the conditions to stop whatever offensive power Moscow can muster. The political stakes are high: the Trump administration is tightening the screws on Kyiv, and Moscow refuses to discuss a ceasefire unless Ukraine hands over the rest of Donetsk Oblast as a bare minimum.
The backbone of Ukraine's defense has been the so-called fortress belt: four industrial cities running north to south, Slaviansk, Kramatorsk, Druzhkivka and Kostiantynivka. For about a year, all have been within range of Russian first-person-view drones, and incremental advances plus improved technology have made Ukrainian logistics noticeably harder and driven many remaining civilians from their homes. In May and June, Russian forces entered and overran much of Kostiantynivka, using the model of mass infiltration backed by drones, artillery and glide bombs that took Pokrovsk last year.
Russia is attempting a double envelopment of the belt with two large pincers. The northern pincer, bearing down on Lyman, was the site of Operation Vivaldi, a series of counterattacks by the 3rd Army Corps under commander Andrii Biletskyi. On the southern flank, Russia has concentrated immense pressure for over a year on the mining city of Dobropillia. After a mass infiltration in August 2025 pushed up to 20 kilometers behind Ukrainian lines, Kyiv redeployed the 1st Azov Corps of the National Guard, commanded by Denys Prokopenko, to the area.
In August, under new Commander-in-Chief Mykhailo Drapatyi, Kyiv divided the defense of the Donbas between two newly formed task forces built up by Biletskyi and Prokopenko. Task Force Azov expanded west, while Biletskyi's Task Force Center took the 11th and 19th Corps, and with them most of the fortress belt. The challenge is bringing exhausted brigades, some fighting for years without rotation, up to the standard of Biletskyi's 3rd Corps.
Through autumn, Russian attempts to push through the hilly terrain east of the fortress belt have bogged down, and Kostiantynivka, which looked likely to fall by the end of summer, is still hanging on. Ukrainian brigades face daily infiltrations and thin, sometimes empty, infantry ranks, but they have adapted: all logistics to infantry positions are handled by heavy bomber drones, and unmanned ground vehicles have become key to keeping drone teams supplied. Inside Kostiantynivka, Ukrainian and Russian positions heavily overlap in the city's residential and industrial areas.