Expert calculations have found Russian military casualties in Ukraine to be very high, although verifying accurate death tolls from war zones is extremely difficult.

NATO estimates the number of Russian soldiers killed in Ukraine since the invasion began at between 7,000 and 15,000.

The estimate is roughly equal to the number of Soviet soldiers killed in more than a decade in the war in Afghanistan.

According to a report in the New York Times in mid-March, US intelligence officials said they believed up to 7,000 Russians had been killed.

The Washington Post also reported around the same time that one of the Russian news websites posted a file – which was quickly re-deleted – claiming that up to 10,000 soldiers had died so far in the conflict.

CBC News analyzes why Russian losses are so high and how long they can last, as well as how difficult it is to get accurate statistics on war zones.

How accurate are the statistics released from Ukraine?

Experts say there is reason to believe that Russia’s estimated death is close to the real thing.

But getting exact figures on the death toll on the battlefield is nearly impossible.

“In conditions of war, you have the fog of war, which makes it very difficult to get accurate figures,” said Walter Dorn, a professor of defense studies at the Royal Military College.

“To see death, you have to go to places where people are dying, which usually means there is a dangerous threat.”

“So it’s difficult for an objective observer to get such an accurate number.”

Stephen Saideman, Paterson Chair in International Affairs at Carleton University and director of the Canadian Defense and Security Network, told CBC News experts don’t immediately believe the figures provided by Russia or Ukraine .

“Each side has an incentive to inflate the damage they’ve done, and deflate the damage that has been done by their opponent,” he said.

“It’s part of every war to do that.”

“Experts from the US and NATO used the model to calculate losses informed by on-the-ground intelligence, satellite imagery, and Russian military awareness,” Saideman and Dorn said.

“That method makes it the most reliable source we can get.”

“We know the size of the Russian battalion, we know how many people are getting into a Russian tank, which tank needs four people, which tank needs three, and we also have a lot of videos and pictures,” Saideman said.

Sean Maloney is a professor of military history at the Royal Military College who has served as a historian of the Canadian army during the conflict in Afghanistan.

He told CBC that, based on his knowledge of the Russian military and sources in Belarus and Russia, NATO’s estimates of Russian casualties were most likely accurate.

“I believe, with the sources I have, the number of Russians who died in the invasion is above 15,000,” Maloney said.

Why were so many Russian soldiers killed so quickly?

If the calculations are accurate, the next question is: Why did a month of the war in Ukraine kill nearly as many Russian soldiers as did the Soviet Union’s decade-long war in Afghanistan?

“War will always be bloodier than the war we are used to because a higher level of explosive power meets a higher level of explosive power,” Saideman said.

Experts say Western democracies have expected a toll similar to that of the US conflict in the Middle East.

Saideman and Maloney say this invasion is a very different kind of war.

Afghanistan and Iraq are “low-intensity conflicts,” Maloney said.

“Yes they do violence, yes people get killed,” he said.

“But in Ukraine, we are dealing with high-intensity mechanized warfare where you have a large number of vehicles, a large number of personnel, a lot of air support colliding at the same time, all over the place. It is continuous, all over the place.”

Another reason for the sheer number of casualties, Saideman said, was Russia’s poor strategy.

“Russia is not preparing the battlefield at all,” he said.

“They didn’t do much of what the American/NATO doctrine normally does, which is to take as much anti-aircraft capability as possible, on the command nodes.”

“The fact that Ukrainians still have power, they still have Internet, they still have communication means it’s easier for Ukrainians to make smart decisions and communicate them effectively.”

Saideman said the Russian military’s medical services were also subpar, which contributed to the death rate.

Reports from Ukraine suggest Russian medics are not handling cases of frostbite properly, along with more serious injuries.

And because there was no pre-invasion bombing, he said, the airspace over Ukraine remains contested.

Ukrainian troops managed to shoot down a helicopter that might have brought the wounded soldiers back from the front.

Maloney said Russia’s poor military situation had left troops on the ground inadequately equipped.

“They don’t care about their personnel, their vehicles are not equipped to protect their people.”

“They are not like our vehicles with fire suppression systems and so on,” he said.

“I’ve never seen an armored ambulance in this entire war.”

“We have it, but I’ve never seen an armored ambulance at all.”

Can Russia endure these losses much longer?

To sustain these heavy losses and continue the war, Russian President Vladimir Putin must maintain the morale on the battlefield and stick to the autocratic regime he leads.

Experts say there is reason to believe that Russia‘s ability to continue the war and Putin’s grip on power could be jeopardized.

Maloney said the Russian military was poorly trained.

He said that about 31 senior Russian military officers, from colonels to generals, died in the invasion.

Losing experienced officers and fighters can damage troop morale.

But poor training, inadequate logistics, and subpar medical support have a bigger effect on Russia‘s war effort, experts say.

“The soldiers who are currently fighting, if they see their comrades being disowned, they will lose the will to fight,” Dorn said.

“If they see their dead comrades, whom they cry for not being returned home, it will have a huge effect on the morale of the Russian troops .”

Despite his iron grip on Russia, Putin must also bear in mind the threat of backlash at home.

“His power base is intelligence and military and if he loses the support of the generals and soldiers, then he knows he can’t stay in power for too long. There is a big risk for him,” Dorn said.

Retired major Michael Boire, a former NATO war planner and assistant professor of military history at the Royal Military College, disagrees.

He said that while the high death toll would be a problem for a country like Canada, Russia was used to the bad news.

“Democracy would say this is a high, unacceptable, and appalling number.”

“But the average Russian would say, ‘That’s war, that’s how it is, that’s how you do business,'” says Boire.

Saideman said that during the Soviet war in Afghanistan, a group of mothers organized to pressure the regime into ending the war and bringing their sons home.

In the short term, he said, battlefield losses in Ukraine would require Putin to spend more resources maintaining power.

In the long term, he added, it could go one of two ways.

“At some point, there will be a large crowd of people and the Russian repression apparatus will appear and they will face the choice of whether to shoot these protesters or not,” he said.

“And we never know how it’s going to turn out until it happens.”