Defense & Geopolitics — 2026-03-24
ISW Assesses Russia Has Begun Spring-Summer 2026 Offensive Against Ukraine's Fortress Belt; 405 of 500 Attackers Killed in Single Assault
The Institute for the Study of War assessed Russia has initiated its Spring-Summer 2026 offensive targeting Ukraine's 'Fortress Belt' in Donetsk Oblast. On March 19, elements of the 1st Guards Tank Army and 20th Guards Combined Arms Army conducted a battalion-sized mechanized assault in the Lyman direction with 500+ personnel, dozens of armored vehicles, and 100+ motorcycles, suffering 405 casualties. Ukrainian CinC Syrskyi confirmed intensified ground attacks across the theater. Russia is deploying PMCs to defend critical infrastructure against Ukrainian drone operations and expanding permanent military installations in Belarus for long-range drone strikes.
Analysis
Prior INTSUM noted ISW's initial assessment of the spring offensive. Casualty figures (405/500 in a single assault) represent the highest single-engagement attrition rate reported since the war began, suggesting Russian forces are pushing through prepared Ukrainian defenses at unsustainable cost.
Prior INTSUM noted ISW's initial assessment of the spring offensive. Casualty figures (405/500 in a single assault) represent the highest single-engagement attrition rate reported since the war began, suggesting Russian forces are pushing through prepared Ukrainian defenses at unsustainable cost.