Ukrainian forces largely halted the Russian spring-summer offensive of 2026, and Russian troops were able to gain a foothold in only a small portion of the territory in May of that year.
This is stated in a report by the Institute for the Study of War (ISW), according to Ukrinform.
The ISW analyzed data suggesting that between December 2025 and May 2026, Russian forces took control of or invaded an area of 40.64 square kilometers. However, during the same period, Russian forces lost 281.1 square kilometers, if we consider only the territory they fully control.
Analysts note that Russian forces have begun actively employing infiltration tactics—sending in sometimes very small groups of a few soldiers into Ukrainian territory, intermingling with Ukrainian positions, yet without actually controlling that territory.
Citing evidence it has gathered independently, the ISW estimates that Russian forces have lost control of approximately 281 square kilometers, partly because ISW analysts have recoded certain areas on their map from “Russian offensive” to “infiltration zones.” Consequently, according to ISW’s calculations, the Russians’ loss of control over 281 square kilometers does not mean that Ukrainian forces have liberated exactly that amount of territory.
