By Ivana Kottasová, CNNRussia's decision to launch a full-scale invasion of Ukraine has now cost the country some 450,000 lives, according to a new study that estimates the war's total casualty numbers to have surpassed 2 million.The research by the Center for Strategic and International Studies (CSIS) estimates Russia has suffered 1.4 million casualties, including killed, wounded and missing soldiers - a stunning number that amounts to roughly 1 percent of the country's population.The losses are not spread evenly across Russia, with poorer areas and ethnic minorities suffering significantly higher casualty rates. Stories of male populations of small remote villages being virtually wiped out are becoming more common in Russian opposition media. And according to the study, Russia is currently unable to recruit new troops at the same rate as it is losing them."These rates are astounding," Seth G. Jones and Riley McCabe, the authors of the study, said. "Russian fatalities in Ukraine are more than four times greater than all US fatalities in all wars combined since World War II, and more than nine times greater than all Soviet and Russian fatalities in all wars combined since World War II."Meanwhile, Ukraine is estimated to have endured between 525,000 and 625,000 casualties, including 125,000 and 150,000 fatalities.Neither Russia nor Ukraine release official casualty data, but the latest CSIS figures are broadly in line with western estimates.Jones and McCabe said that in terms of casualties, the war was becoming much more costly for Russia than it was for Ukraine. They said the casualty rate had likely risen to nearly eight to one in the first half of this year, meaning that for every Ukrainian soldier killed, wounded or missing, there were eight Russian casualties.For much of the war, the rate stood at between two to three Russian casualties to one Ukrainian loss. Jones and McCabe said that the recent increase was down to Kyiv's advances in its drone programme, especially its ability to greatly extend the "kill zone" - the area around the frontlines that is so saturated with drones that it makes it almost impossible for Russian troops to enter."Ukraine's defence-in-depth strategy has been effective in killing and wounding Russian soldiers, as well as limiting Russian manoeuvre," they said.However, they said there were other reasons why Russia was suffering so much, including "Russia's attrition strategy, its failure to effectively conduct combined arms and joint warfare, its poor tactics and training, corruption, and low morale".Whatever the reasons, the data paints a horrendous picture: with 2 million total casualties, the war in Ukraine has now likely surpassed the battle of Stalingrad, widely considered to be the bloodiest conflict in history.- CNN