Ukraine’s Operation Vivaldi counteroffensive north of Lyman has reversed months of Russian gains in northern Donetsk Oblast, with independent assessments showing Russia recording a net territorial loss of roughly 80 square kilometers in September 2026 as Ukrainian forces recaptured settlements, severed logistics routes, and forced Russian redeployments. This has disrupted Moscow’s efforts to encircle the Sloviansk-Kramatorsk fortress belt from the north. Russian forces continue grinding assaults in southern sectors toward key remaining Ukrainian-held areas, yet overall advances across the front have slowed markedly from prior years amid Ukrainian defensive reorganizations and strikes on supply lines. These battlefield shifts represent the primary recent driver of trader views on timelines for full Russian control of the oblast.