Operation Vivaldi Worked, But Neither Side Can Break the War's Stalemate

Ukrainian soldiers who fought in Operation Vivaldi credit a fresh tactic for their success near the Siverskyi Donets River north of Sloviansk. They are refusing to explain it, so they can hit the same Russian weak spots again. Based only on videos released by both sides, the operation's pace and methods mirrored other fights in this war: forces spent months chipping away, small assault groups infiltrated, and there was no sign of maneuver warfare. The advance ran 10–15 kilometers deep.

Former 3rd Army Corps commander Andriy Biletsky and his brigade commanders said preparations started back in May. By the fall, after a long stretch of shaping the battlefield, Ukrainian forces liberated a large area fast. On a podcast hosted by military analyst Rob Lee, an American volunteer serving in the 3rd Army Corps compared the buildup to a mountain avalanche — slow changes in the snowpack, then a mass that sweeps everything away. He wouldn't explain the metaphor.

The published videos, most released months after filming, show the advance creeping forward over the summer. Ukrainian forces cut supplies to support units of Russia's 20th Combined Arms Army, which was holding a stretch of front north of Lyman — drone operators, electronic warfare crews and others who anchor defenses in this war. Then assault troops moving from the west, north and south had to clear infantry in four settlements: Novoselivka, Shandryholove, Kolodiazi and Nove. Stripped of reconnaissance and most strike assets, the 20th Army abandoned nearly all its positions west of the Chornyi Zherebets River, and artillery and drone fire from the eastern bank stopped the Ukrainians at the water.

Across the months-long offensive, Ukraine advanced 10–20 kilometers. Tactically that looks small; operationally it matters. Kyiv's command is even talking up the win, with military sources claiming they uncovered a Russian plan to encircle Ukraine's entire force in the Kramatorsk–Sloviansk area and take all of the Donbas. That plan, per Ukrainian officials, called for the 20th and 25th Armies to seize Sviatohirsk, cross the Siverskyi Donets — more than 100 meters wide — and reach the Sloviansk–Izium road, while the Center grouping grabbed Dobropillia and pushed toward Barvinkove. But Russian deployments point to something more modest: the 20th Army's two motorized rifle divisions and 24–27 rifle battalions never looked like a force built to cross a major river and trap Ukrainian troops.

Biletsky has just been promoted to command Ukraine's newly formed Center grouping, putting him in charge of operations on the southern bank of the Siverskyi Donets as well, where Ukrainian forces appear to have started shaping the battlefield. That enemy is clearly stronger than the 20th Army's forward detachments near Lyman. Russia, meanwhile, ran its own version of the operation southwest of Kramatorsk: after months of disrupting Ukrainian logistics and driving out support units, it captured Dobropillia and reached the Dobropillia–Kramatorsk road, advancing 20–25 kilometers since January 2026.

Both sides' endgames are plain. The Kremlin wants Kramatorsk and Sloviansk to show Volodymyr Zelensky and Ukrainians that resisting the handover of Donbas territory was pointless; Kyiv wants to convince Vladimir Putin that Russia's push on Kramatorsk cannot succeed. Both armies have learned to advance, but only after months of preparation. Gains of a few dozen kilometers a year require hundreds of thousands of troops on each side and come at the cost of enormous casualties.