
Russia’s Spring Offensive Quietly Targets Ukraine’s Fortress Belt from Lyman toward Slovyansk
ISW assesses Russia has likely begun its Spring-Summer 2026 offensive against Ukraine’s Fortress Belt in Donetsk Oblast, pressing in the Lyman direction toward Slovyansk with a dispersed, battalion-sized assault backed by air interdiction and drone strikes; Ukrainian forces report heavy Russian casualties and ongoing countermeasures, and ISW warns that major fortress-belt seizure this year is unlikely, though tactical gains at high cost are possible, as Ukraine maintains long-range strikes in Russia and advances near Kupyansk and Pokrovsk.












