Ukraine's Operation Vivaldi thwarts Russian plan to encircle Donbas

The Ukrainian counteroffensive in the direction of Lyman has thwarted Russia's plan to encircle and occupy the part of the Donetsk region that continues to be controlled by Ukraine, according to an analysis by the Washington-based Institute for the Study of War (ISW).

The Ukrainian operation, codenamed "Vivaldi," has destroyed the northern flank of a Russian encirclement maneuver, liberating up to 176 square kilometers of territory and forcing Russian units to go on the defensive.

According to ISW, the Russian campaign aimed to encircle the so-called “fortified belt,” a defensive and logistical network that protects the part of Donbass under Ukrainian control. The plan called for Russian forces to advance from Lyman in the north and Dobropillia in the southwest, with the aim of the two flanks joining up near Barvinkovo, in the Kharkiv region.

The realization of this encirclement would bring Moscow closer to its long-term objective of occupying the entire Donetsk region and would offer the Kremlin an important result to present to Russian public opinion, relative to the costs of the war.

However, the Ukrainian counteroffensive on the Lyman axis thwarted this plan. Ukrainian forces advanced along the Ridkodub–Nove–Novomykhailivka line in the north and Yarova–Drobysheve–Stavky in the south, collapsing the advanced Russian positions threatening Sloviansk from the northeast.

The commander of the Third Army Corps of Ukraine, Andrii Biletskyi, stated that the first three phases of the operation, conducted from mid-to-late September, liberated 176 square kilometers of territory.

Ukrainian President Volodymyr Zelenskyy gave a lower figure of 125 to 140 square kilometers for the situation as of October 3. He also said that Russian losses had increased significantly over the previous two to three months.

ISW estimates that the success of the operation may be even greater than Kiev's official figures indicate.

Russia loses positions for attack on Sloviansk

According to the institute, the failure of the northern wing of the encirclement maneuver forced Russia to abandon plans to advance towards Sloviansk from the northeast. This deprived Russian forces of positions intended to allow them to threaten the northern approaches to the fortified Ukrainian strip.

Maintaining Ukrainian control over the Lyman area has also helped maintain key supply routes. Meanwhile, some Russian units from other parts of the front may have been moved to reinforce the northern sector.

In these circumstances, the Russian advance from the Pokrovsk–Dobropillia area to the southwest, the remaining arm of the initial encirclement plan, now faces much more ambitious objectives alone.

ISW calls the collapse of the northern flank an operational failure for Russia, as Moscow has not only lost territory around Lyman, but also a key part of the plan to defeat Ukrainian defenses in Donbas.

Russian forces continue to hold some positions gained in the Kostyantynivka area and east of Sloviansk, but have encountered difficulties maintaining the pace of advance in both areas.

According to the analysis, reliance on infantry penetrations, drones, and bombing can cause gradual attrition of opposing forces, but does not enable the rapid mechanized maneuvers needed to breach Ukrainian defenses on the scale required by Moscow.

ISW notes that the situation on the front remains volatile and that Russian forces may adjust their tactics over time. However, for now, Ukraine appears to have managed to halt Russian advances in this sector. Further Russian mobilization and technological adaptations could change the situation, but do not necessarily guarantee a successful breakthrough.

ISW rejects Russian claims of territorial occupation

The institute also questioned claims, widely circulated by pro-government Russian media, that Russian forces had occupied 1,301 square kilometers of Ukrainian territory in September alone. This figure was about two and a half times higher than that reported in previous months.

Relying on geolocated photographs and videos, satellite imagery, and visually confirmed data, ISW calculated that Russian assault units had lost control over at least 80 square kilometers of territory during September.

According to the institute's calculations, the net Russian withdrawal during the month amounted to 175.18 square kilometers, including areas where Russian troops had temporarily penetrated but failed to establish sustainable control.

Last week, Russian President Vladimir Putin stated at the Valdai Club meeting that Russia now controls 89 percent of the Donetsk region. In contrast, ISW estimates that the territory of the region occupied by Russia does not exceed 81 percent.

The institute described Putin's claims of Russian advances during September as so far from reality that, in its opinion, they "resemble hallucinations."

The ISW said it could not determine whether Putin is aware that the figures he cites are false, or whether he has come to believe the fabricated data he receives from the front lines. The institute said this could be linked to an entrenched culture of dishonesty within the Russian military command.