The 66th Mechanised Brigade reversed months of retreat by seizing high ground, cutting Russian logistics, and liberating two villages in six weeks during Operation Vivaldi.
Inside the Turnaround
New York Times journalists spent two weeks with troops of Ukraine’s 3rd Army Corps, including the attached 66th Brigade, during the active phase of Vivaldi. In an underground command post, dozens of screens carried live battlefield feeds. Yurii Horobets, commander of the brigade’s 2nd Mechanised Battalion, kept his soldiers focused on the fighting unfolding across them.
A year earlier, the brigade had been falling back. Russian troops outnumbered it. Roads were under fire. Ukrainian units struggled both to deliver ammunition and to evacuate the wounded. The battalion was a ragtag formation: many of its infantrymen, like Horobets, were in their 40s or 50s, serving with ageing equipment and too few people.
Commanders took the initiative. They captured the high ground Russia had used to observe and correct its fire. They disrupted Russian communications. They attacked the routes and logistics drones bringing supplies forward. After a month, the 66th advanced and liberated its first village following months of retreat. Six weeks later, it took another.
The Logistics Fight
The brigade’s commanders say coordination changed after Andrii Biletskyi took command of the 3rd Army Corps in summer 2025. Six brigades on that sector began acting together. Commanders at the front made decisions rather than waiting for a distant headquarters. Neighbouring units closed gaps between their areas that Russian troops had exploited.
Medium-range drones extended the fight far behind Russian positions. Corps forces struck up to 50 Russian vehicles a day, sometimes as far as 160 kilometers out. Russian troops were forced to unload 40–50 km back and continue on foot; in one account, a soldier carried a single artillery shell for more than 30 km. Ukrainian drones also hit attempts to bring food closer to the line.
Ground robots carried food, water, ammunition, batteries and even mini-excavators to Ukrainian positions. Some broke down or were destroyed. Others got through and sometimes brought back the bodies of fallen soldiers. Biletskyi says his brigades deliver three times as much cargo to their troops as brigades in other corps.
Biletskyi says Vivaldi wrecked Russia’s plan to encircle Sloviansk and Kramatorsk and that his forces effectively destroyed a Russian division.
The shift began with Ukrainian troops solving the immediate problem in front of them: taking away Russia’s view of the battlefield, then making it harder for Russian soldiers to reach it supplied.