Ukrainian forces have achieved incredible success.
12.10.2026
The advances made by Ukrainian forces north of Lyman during Operation “Vivaldi” exceed the results officially reported by the Ukrainian side. This assessment was provided by the U.S.-based Institute for the Study of War (ISW) in its report “Ukraine Thwarts Russian Offensive on Donetsk,” published on October 8.
Analysts cited a statement by the commander of the 3rd Army Corps Andriy Biletsky regarding the clearing of 176 km² of territory from Russian forces during the first three phases of the operation. At the same time, drawing also on reports from Russian military bloggers, the ISW considers the Ukrainian gains to be more significant. The institute did not provide its own estimate of the area of liberated territory.
In the forecast section of the report, the ISW noted that the 3rd Corps thwarted Russian attempts to capture and bypass Lyman and eliminated the Russian salient north of the city. Analysts emphasized that details of the operation continue to emerge and that Ukrainian forces may have achieved even more significant results.
According to the institute’s assessment, “Vivaldi” dealt an operational defeat to the northern group, which was supposed to encircle the Ukrainian “belt of fortresses” — Slavyansk, Kramatorsk, Druzhkivka, and Kostiantynivka. The operation also thwarted Russian plans to encircle Slavyansk from the northeast.
The ISW believes that these results are forcing the Russian command to revise its plans for the offensive campaign in the Donetsk region. Before attempting to capture or encircle Slavyansk again, Russian forces will have to restore their combat effectiveness and retake the positions they have just lost.
According to analysts, the two Russian combined-arms armies operating in the Liman sector and north of Liman are likely significantly depleted by months of Ukrainian counterattacks and are not in a position to resume the offensive.
The ISW predicts that the Russian command will have to either abandon the northern part of its encirclement plan or redeploy significant forces from other sectors of the front to counter Ukrainian counterattacks. Such a redeployment could weaken other Russian offensive operations.
Separately, analysts drew attention to false reports within the Russian army. In their assessment, the command’s distorted view of the front line hinders a timely response to Ukraine’s actions. Ukrainian forces, in turn, exploited this situation to maintain the secrecy of the operation and the element of surprise in their strikes.
At the same time, the ISW warned that the success of “Vivaldi” does not eliminate the immediate threat to Konstantinovka. Russian troops continue to attack in other parts of the Donetsk region, and the long-term consequences of the Ukrainian operation have yet to be assessed.
https://charter97.org/en/news/2026/10/12/701633