Russian Offensive Campaign Assessment, September 17, 2026 - Institute for the Study of War

Ukraine’s Operation Vivaldi in the Lyman direction demonstrates Ukraine’s recent progress in restoring elements of tactical maneuver on the battlefield, enabled in part by Ukraine’s shaping operations and intermediate-range strike campaign that degrades Russian electronic warfare (EW) capabilities. Ukrainian 3rd Army Corps Commander Brigadier General Andrii Biletskyi stated on September 17 that a Ukrainian counteroffensive against the Russian salient north of Lyman — Operation Vivaldi — thwarted Russia’s plan to encircle the Fortress Belt from the north through Lyman and Svyatohirsk and the south through Dobropillya.