More than 1.8 million soldiers from Russia and Ukraine have been killed, wounded, or gone missing during nearly four years of war, according to a report by the U.S.-based think tank Center for Strategic and International Studies (CSIS). The report, published on January 28, 2026, found that Russian forces suffered significantly higher losses, with about 1.2 million affected, including over 325,000 killed and several thousand still missing. CSIS noted that no major military power has faced such heavy losses in any conflict since World War II.

Ukraine has also endured severe casualties, with more than 600,000 soldiers killed, wounded, or missing between February 2022 and December 2025. The report estimated Ukrainian military deaths between 100,000 and 140,000 during that period. CSIS warned that if the war continues, total casualties could reach around two million by spring 2026.

The conflict began on February 24, 2022, when Russia launched a military operation in Ukraine following long-standing tensions over Crimea and Ukraine’s efforts to join NATO.