AMNA NAWAZ: New research estimates Russian forces have suffered more than one million casualties in its war against Ukraine.

At the same time, its territorial gains have been some of the slowest in modern history.

Tonight, we get a rare look at the Kremlin's war machine.

Special correspondent Simon Ostrovsky reveals the brutality and the corruption eating away at the Russian military from the inside.

And a warning: Viewers may find some scenes in this report disturbing.

SIMON OSTROVSKY: In Russia's military, men learn quickly to fear their commanders more than their foe.

This is the treatment awaiting those who refuse to hand over their pay.

Hundreds of videos circulating on Russian social media reveal horrific punishments by superiors extorting money from their men.

Soldiers report being locked in cages, electrocuted and sexually assaulted.

Those wounded, but lucky enough to survive, must pay thousands more to be declared unfit for service, or they're force to literally limp into battle.

MAN (through translator): Russian warriors, this is how we go to the front.

SIMON OSTROVSKY: Corruption dictating who lives and who dies.

In Russia, military cemeteries are running out of space to bury the dead, while the authorities are trying to keep the scale of their losses secret by blurring them on maps.

New research published by the Center for Strategic and International Studies in Washington, D.C., shows the extraordinary price Russia is paying as its war in Ukraine grinds on into its fifth year.

Between the start of the full-scale invasion in 2022 and the end of last year, Russian forces have suffered 1.2 million casualties, which include the dead, wounded and missing.

Out of that staggering number, as many as 325,000 are believed to be dead.

One of the report's authors is Seth Jones, a former senior official in the Department of Defense.

He said many Russians are dying because they're unable to pay bribes and are being sent to the front lines to be killed.

SETH JONES, Center for Strategic and International Studies: They're being used as bait, so they draw fire.

And when there's artillery that goes off, Russian artillery or Russian drones are able to, say, spot where Ukrainian locations are.

SIMON OSTROVSKY: One of the things I have been struck by as I have looked at the video footage that's come out of this war is that you often see soldiers who are totally unfit for duty.

I'm talking about people who are on crutches, people who are missing limbs.

You have to ask yourself, why is this happening?

What kind of a strategy is that?

SETH JONES: I think this is where the Russians believe this is the least worst strategy, because they have an advantage in numbers.

The problem, of course, is that it leads to historical numbers of casualties.

It is unprecedented since World War II.

SIMON OSTROVSKY: Another way of looking at it is by comparison to America's deadliest war since World War II, the Vietnam War.

Here in Washington, D.C., at the Vietnam War Memorial, the names of service men and women who died and went missing in Vietnam are commemorated on these walls.

In total it's about 58,000 names.

Russia's war dead in just four years are more than five times that number.

And the multiple is even higher if you consider the missing in action.

After nearly two decades, the widely unpopular Vietnam War ended with an embarrassing withdrawal of American troops and the fall of South Vietnam.

With Ukraine, the Kremlin has managed to project strength both at home to its citizens and abroad when it comes to negotiating for land.

Last year, President Donald Trump even told his aides the Russian army looked invincible after seeing footage from this military parade in Moscow.

Yet, on the actual battlefield, Russia's forces have advanced at a slower pace than any major offensive campaign in any war in the last century.

SETH JONES: We're seeing average rates of advance around 15 meters per day and in some cases up to 70 meters per day.

The... SIMON OSTROVSKY: The advances are being measured in meters.

SETH JONES: Meters, right.

SIMON OSTROVSKY: That sounds like World War I. SETH JONES: It's even slower than World War I. So this is slower than some of the slowest and most casualty-accepting campaigns we have seen in any war in the last century.

SIMON OSTROVSKY: In Russia, promises of generous sign-up bonuses and a steady paycheck have managed to feed enlistment drives, with recruitment targeted at the country's poorest regions.

For now, that's helped compensate for the high battlefield casualty rates.

WOMAN (through translator): Heartbreaking.

Our boys are once again being sent to the special military operations zone.

SIMON OSTROVSKY: Leaked messages sent to this government Web site show mounting desperation among Russian soldiers and their families.

Obtained by the independent Russian outlet Radio Echo, nearly 12,000 complaints filed over six months last year accused commanders of corruption and violence towards their own men.

In this 2025 video, military police in the Siberian region of Tuva beat and electrocute wounded soldiers to force them back to the front.

Alexandra Arkhipova is a Russian researcher who's spent weeks sifting through these letters to verify their authenticity and catalog the brutality that the Russian military is inflicting on its own men.

ALEXANDRA ARKHIPOVA, Wilson Center: In many cases, in many letters, the people are saying that literally we paid everything to have our father, brother, husband not to be killed.

In many cases, superiors, they use tortures to take money from the soldiers.

MAN (through translator): How the (EXPLETIVE DELETED) did you end up here?

MAN (through translator): I refused to go on the mission.

MAN (through translator): Why the (EXPLETIVE DELETED) did you think you could do that?

MAN (through translator): I'm wounded.

SIMON OSTROVSKY: And this is the Russian army doing this to its own soldiers?

ALEXANDRA ARKHIPOVA: Yes, correct.

SIMON OSTROVSKY: She told PBS News the army shifts the cost of the war in Ukraine onto the soldiers themselves through extortion.

Soldiers report handing over up to 80 percent of their salary just to stay alive.

MAN (through translator): What did he do to you?

MAN (through translator): He shoved a (EXPLETIVE DELETED).

MAN (through translator): Why?

What for?

MAN (through translator): Because I didn't give him money.

MAN (through translator): How much was he demanding?

MAN (through translator): Thirty nine hundred dollars.

SIMON OSTROVSKY: Price lists dictate new rules of engagement, $2,000 to be assigned to a post as a drone operator away from the front line, $6,000 to serve in the rear, a staggering $12,000 for a forged discharge on medical grounds.

The picture you describe is hellish.

If the entire military is functioning like this, it couldn't really perpetuate the war for much longer.

ALEXANDRA ARKHIPOVA: The situation in Russia, from the economical point of view, is very bad.

Poor people, they became poor, so they go to the war.

Taxes are going up.

And it's a big problem now what to buy for dinner.

And this is the price of the war.

SIMON OSTROVSKY: With Russian oil and gas revenues down 24 percent last year, the price of war is no longer just the 35,000 Russian casualties a month.

It's also new taxes the government has been forced to levy, coupled with skyrocketing prices for consumer goods.

In the fifth year of what was meant to be a three-day war, the outlook for Russia has never been so grim.

For the "PBS News Hour," I'm Simon Ostrovsky in Washington, D.C.