Four years of Russian invasion of Ukraine: The alarming human cost of the deadliest war in Europe since World War II

Tuesday, February 24, 2026, marks four years since Russia invaded Ukraine. The invasion, which Russian President Vladimir Putin called a special military operation, was aimed at liberating the self-declared Donetsk and Luhansk People’s Republics, two breakaway regions of Ukraine.

When the special military operation was announced, the Kremlin originally expected it to last a couple of days or a week, with a goal of quickly capturing Kyiv and overthrowing the Ukrainian government led by President Volodymyr Zelenskyy.

Four years of Russia-Ukraine war

But Russia heavily overestimated its abilities and underestimated the Ukrainian resistance, resulting in the conflict being dragged into weeks, months, and years, entering its fifth year, with no clear path to peace.

While the Ukrainians managed to resist the invasion and the capture of their homeland as a whole by Russia, the resistance came at a high cost.

Ukrainian death toll

Though it is nearly impossible to count all the fatalities in the past four years, various estimates put the Ukrainian military casualties anywhere from 500,000 to 600,000. This is much higher than the documented cases of deaths and missing-in-action, which is over 175,000.

Ukrainian civilians have also suffered mass casualties in the past four years, with the United Nations verifying more than 15,000 deaths and over 41,000 injuries, including more than 3,200 children. Over 19,000 Ukrainian children have been allegedly abducted or forcibly deported to Russia in the past four years.

Even with these shocking numbers, many believe that the real death toll in Ukraine is much higher, as those killed in currently Russian-occupied territories like Mariupol have not been ascertained.

Refugees and internally displaced

Ukraine, the poorest country in Europe, has also suffered significant manpower losses due to the war in the form of displacement. According to UN data, nearly 11 million Ukrainians, which is about a quarter of the country’s pre-war population was forced to flee their homes since the start of the invasion in February 2022. Out of this, around 6.9 million have become refugees abroad, and another 3.7 million have been displaced internally.

The UNHCR estimates that around 12.7 million people in Ukraine are in need of humanitarian assistance for basic necessities like food, water, and medicine.

How war with Ukraine has affected Russia

The war has also taken a toll on Russia, in the form of international isolation and crippling economic sanctions, targeted at the country’s energy sector. The war, which was envisioned as a quick in-and-out operation, has also dealt a major blow to the Russian military’s morale, which is at an all-time low.

Russian battlefield losses

Like Ukraine, Russia has also been secretive about its battlefield losses, which have not been officially updated since the Kremlin acknowledged the death of 5,937 soldiers in September 2022.

Other estimates, including those by independent observers and media houses, put the Russian military losses in Ukraine anywhere from 230,000 to well over 1 million.

According to the Center for Strategic and International Studies (CSIS) estimated up to 325,000 deaths as of December 2025. The UK Ministry of Defense estimates that up to 1.2 million Russian soldiers may have been killed in Ukraine.

The BBC has also verified the names of at least 186,102 Russian soldiers killed in Ukraine by cross-referencing official reports, social media obituaries, and cemetery records.

2025 was the deadliest year for Putin’s troops on the battlefield, with The Economist suggesting that around 1,000 Russian soldiers were being killed every day.