A new study by the Washington-based Center for Strategic and International Studies (CSIS) has estimated that more than two million Russian and Ukrainian troops have been killed or wounded since Russia launched its full-scale invasion of Ukraine in February 2022, highlighting the enormous human cost of a war now entering its fifth year.
The report, released on Wednesday, estimates that Russia has suffered the heavier losses, with about 1.4 million military casualties, including approximately 450,000 deaths.
According to the study, the number of Russian troops killed is nearly four times higher than the total number of U.S. military fatalities recorded across all wars since the end of World War II.
Ukraine’s military casualties were estimated at between 525,000 and 625,000, including between 125,000 and 150,000 personnel killed.
The authors of the report cautioned that casualty figures remain difficult to verify, noting that Russia is widely believed to underreport its military losses while Ukraine has not publicly disclosed official casualty data. The estimates were compiled using figures from U.S. and British government assessments, among other sources.
Despite the high losses, Russia has continued to make only limited battlefield gains. The report said Russian troops have advanced in some areas at a pace of less than 165 feet per day.
It added that Ukraine recorded its first month of net territorial gains since 2023 in February after launching offensives in the country’s south.
“Russia’s territorial control in Ukraine shrank in the spring of 2026,” the study stated. “Russian forces lost more ground than they captured in both April and May, a net loss of roughly 400 square kilometers and their first monthly net losses since August 2024 — yet another sign of Russia’s military struggles.”
The report also credited an unexpected development involving billionaire Elon Musk’s Starlink satellite internet service with briefly improving Ukraine’s battlefield position.
According to the analysts, Musk blocked Russian forces from accessing Starlink in February, reducing the effectiveness of Russian drone operations and allowing Ukrainian troops greater freedom of movement.
Although Russia has suffered greater overall casualties, analysts noted that Ukraine is losing a larger proportion of its smaller military force.
Military analysts estimate that more than 400,000 Russian troops are currently deployed along the front lines, compared with about 250,000 Ukrainian soldiers.
Russia has maintained its troop strength despite mounting losses through a combination of compulsory military service, recruitment incentives and the enlistment of prisoners and debtors. President Vladimir Putin has also offered financial bonuses to recruits and reportedly allowed criminal suspects to avoid prosecution in exchange for military service.
The report further noted that North Korea contributed more than 10,000 troops during 2024 and 2025 to assist Russia in retaking parts of its Kursk region after Ukrainian forces seized territory there.
However, the study suggested Russia’s manpower challenges are becoming increasingly severe, estimating monthly casualties in 2026 at between 30,000 and 34,000 troops, exceeding recruitment levels of roughly 27,000 new personnel each month.
The findings come as U.S. President Donald Trump has reduced Washington’s involvement in the conflict.
Speaking at a summit in France last month, Trump signaled that ending the war was no longer a top foreign policy priority.
“Look, we have nothing to do with it,” Trump said. “It has no impact on us, other than we sell weapons” to Ukraine.
His comments reflected a significant shift in U.S. policy that has prompted European allies to reassess their long-standing reliance on American security guarantees.
While Trump has framed U.S. involvement primarily as a humanitarian effort aimed at ending the bloodshed, supporters of Ukraine, including members of the U.S. Congress, argue that preventing a Russian victory remains essential to deterring further aggression against NATO member states.
The war is expected to feature prominently during a NATO summit scheduled to take place in Ankara, Turkey.
The CSIS report warned that without increased pressure from the United States and Europe, Putin is likely to continue pursuing the war despite Russia’s mounting casualties.
The study also highlighted Ukraine’s growing ability to strike targets inside Russian territory using drones and missiles.
Last month, Ukraine carried out what analysts described as its largest drone attack on Moscow since the war began. This week, Ukrainian forces launched additional drone strikes targeting Moscow and Crimea, the peninsula Russia annexed from Ukraine in 2014.
Russia’s Defence Ministry said it intercepted 419 drones during the latest wave of attacks.
“Russia is facing, by far, its darkest period of the war since its February 2022 invasion of Ukraine,” said Seth G. Jones, one of the study’s authors.
“The war has come home to everyday Russians, who are paying the price of President Putin’s war with a sputtering economy, skyrocketing prices, a growing number of body bags coming back from the front lines and drone strikes in Russian cities.”
