The number of Russian and Ukrainian troops killed, wounded or missing in nearly four years of war could reach 2 million by this spring, a Washington-based report warns. The Center for Strategic and International Studies (CSIS) estimates Russia suffered around 1.2 million casualties, including up to 325,000 deaths. Ukraine's losses are close to 600,000. Neither side has officially shared full casualty numbers, keeping them secret. The Kremlin dismissed the CSIS report on Wednesday as “not credible” and said only the defence ministry can release Russian figures. CSIS based the estimates on interviews with western and Ukrainian officials and data from independent sources like Mediazona and BBC Russian Service. The losses are huge by historical standards. Russian battlefield deaths in Ukraine are “more than 17 times greater than Soviet losses in Afghanistan during the 1980s,” the report says. They are also 11 times higher than in the Chechen wars and five times greater than all Russian and Soviet wars combined since World War II. Russia’s casualties are estimated to be about 2 to 2.5 times those of Ukraine, but Ukraine’s smaller population and limited troop-raising capacity make this toll very damaging. Russia uses pay and benefits to attract new recruits, including thousands from Asia, South America and Africa. Some of these recruits faced misleading promises or pressure. Ukraine struggles to mobilise enough soldiers and President Volodymyr Zelenskyy has avoided lowering the draft age below 25, which would be unpopular. Despite heavy losses on both sides, Russia's land gains remain very small. CSIS reports that since 2024, Russian forces advanced only 15 to 70 metres per day during major attacks, “slower than almost any major offensive campaign in modern warfare.” Winter and stiff Ukrainian defence have slowed progress further after small advances late last year. Between January 1 and 25, Russia captured 152 square kilometres, the slowest advance since March 2023, according to Ukrainian group DeepState. Last weekend, Russia, Ukraine and the US met in Abu Dhabi for the first peace talks since the war began, but no breakthrough happened. Russia still demands large areas of Ukrainian land.