Dima never puts out a cigarette until he has smoked it all the way to the filter, risking burning his fingers to squeeze out another drag. He spent years at the front in Ukraine. He knows the price of a good smoke.

As a battalion commander, Dima was in charge of some 800 men who fought in some of the fiercest, bloodiest battles of the war – most recently near Pokrovsk, the strategic eastern city now on the verge of falling to Russia.

But with most of his soldiers now dead or seriously injured, Dima decides he's had enough. He resigned and got another job in the army – in an office in Kiev.

Standing outside that office, smoking cigarettes and drinking sweet coffee, he told CNN he just couldn't bear to watch his people die anymore.

The two and a half year Russian offensive decimated many Ukrainian units. Reinforcements are few and far between, leaving some soldiers exhausted and demoralized. The situation is particularly bad among infantry units near Pokrovsk and elsewhere on the eastern front line, where Ukraine is struggling to halt Russia's creeping advance.

CNN spoke with six commanders and officers who until recently fought or supervised units in the area. All six said desertion and insubordination were becoming a widespread problem, especially among newly recruited soldiers.

Four of the six, including Dima, asked that their names be changed or withheld due to the sensitivity of the topic and because they are not authorized to speak to the media.

"Not all mobilized soldiers leave their positions, but the majority do. When new guys come here, they see how hard it is. They see a lot of enemy drones, artillery and mortars," a unit commander currently fighting in Pokrovsk told CNN. He also asked to remain anonymous.

"They go to the positions once and if they survive, they never come back." "They either abandon their positions, refuse to go to battle or try to find a way to leave the army," he added.

Unlike those who volunteered earlier in the war, many of the new recruits had no choice but to enter the conflict. They were called up after Ukraine's new mobilization law took effect in the spring and cannot legally leave until the government introduces demobilization unless they receive special permission to do so.

However, the discipline problems apparently started long before this. Ukraine went through an extremely difficult road during the last winter and spring. A month-long delay in getting US military aid into the country led to a critical shortage of ammunition and a severe drop in morale.

Multiple soldiers told CNN at the time that they would often find themselves in a good position, with a clear view of an approaching enemy and no artillery ammunition. Some spoke of feeling guilty for not being able to provide adequate cover for their infantry units.

"The days are long, they live dug in, they are on duty around the clock, and if they can't fire, the Russians have an advantage, they hear them advancing and they know that if they fired, it wouldn't have happened. " said Andrii Horetsky, a Ukrainian military officer whose unit is now fighting in Chasiv Yar, another hot spot on the eastern front line.

Serhiy Tsehotskyi, an officer with the 59th Separate Motorized Infantry Brigade, told CNN the unit tries to rotate soldiers in and out every three to four days. But drones, which have only increased in number over the course of the war, may make that too dangerous, forcing soldiers to stay longer. "The record is 20 days," he said.

As the situation on the battlefield worsened, more and more soldiers began to give up. In the first four months of 2024 alone, prosecutors opened criminal proceedings against nearly 19.000 soldiers who either abandoned their posts or deserted, according to the Ukrainian parliament.

More than a million Ukrainians serve in the country's defense and security forces, although this figure includes everyone, including people working in offices far from the front lines.

That's a staggering and – most likely – incomplete number. Several commanders told CNN that many officers will not report desertions and unauthorized absences, hoping instead to persuade soldiers to return voluntarily without facing punishment.

This approach has become so common that Ukraine changed the law to decriminalize desertion and absence without permission if they do it for the first time.

Horecki told CNN the move made sense. "Threats will only make things worse." "A smart commander will delay threats and even avoid them," he said.

Pokrovsk became the epicenter of the struggle for the east of Ukraine. Russian forces have been advancing on the city for months, but their advance has accelerated in recent weeks as Ukrainian defenses have begun to crumble.

"Everything Feels the Same"

Russian President Vladimir Putin has made it clear that his goal is to gain control over the entirety of Ukraine's Donetsk and Luhansk regions, and taking Pokrovsk, an important military and supply hub, would be a major step toward that goal.

It is located on a key road connecting it to other military towns in the area and to a railway connecting it to the Dnieper. The last major coke mine still under Kiev's control is also west of the city, supplying coke for steelmaking – an indispensable wartime resource.

Ukrainian soldiers in the area paint a grim picture of the situation. Kiev's forces are clearly outnumbered and outgunned, with some commanders estimating that there are 10 Russian soldiers for every Ukrainian.

But they also seem to be struggling with problems of their own making.

An officer from the brigade fighting in Pokrovsk, who asked that his name be withheld for security reasons, told CNN that poor communication between different units is a major problem there.

There were even cases where soldiers did not reveal the full picture of the battlefield to other units for fear of looking bad, the officer said.

A battalion commander in northern Donetsk said his flank was recently left exposed to Russian attacks after soldiers from neighboring units abandoned their positions without reporting.

The large number of different units Kiev has sent to the eastern front lines has caused communication problems, according to several soldiers who fought in Pokrovsk until recently.

One said it was not unheard of to have Ukrainian signal jammers affecting vital coordination and drone launches because units from different brigades were not communicating properly.

A group of sappers -- or combat engineers -- spoke to CNN near the border between Ukraine and Russia's Kursk region, where they were recently redeployed south of Pokrovsk.

Kiev launched its surprise incursion into Kursk last month, taking Moscow by surprise and rapidly advancing about 30 kilometers into Russian territory.

Ukrainian leaders, including President Volodymyr Zelensky, have said one of the goals of the operation is to prevent further attacks on northern Ukraine, while showing Kiev's Western allies that, with the right support, the Ukrainian military can fight back and eventually win the war.

The operation also provided a major boost to the depleted nation. Ukraine has been on the back foot for most of the past year, suffering relentless attacks, blackouts and heartbreaking losses.

But the sappers weren't too sure about the strategy. Having just completed a long mission over the border, they were slumped around a table outside a closed restaurant near the border, waiting for their car to show up.

Smoking cigarettes and trying to stay awake, they wondered why they had been sent to Kursk when the eastern front line was in disarray.

"It was strange for me to enter Russia, because in this war we were supposed to defend our country and our country, and now we are fighting on the territory of the other country," said one of them.

CNN is not releasing their identities because they were not authorized to speak to the media and because of the sensitive nature of their words.

All four have been fighting for more than two and a half years and their work is difficult. As sappers, they spend days on the front lines, clearing minefields, preparing defenses and conducting controlled explosions. They can find themselves under attack, even in front of the front line of infantry, hauling around 40kg of kit and four anti-tank mines, each weighing around 10kg.

Speaking to CNN, they appeared completely exhausted. They had no rest between their mission at Pokrovsk and that at Kursk.

"It depends on each commander. "Some units get rotations and have free time, while others just fight non-stop, the whole system is not very fair," said one of the soldiers.

Asked whether the Kursk advance had given them the same boost as the rest of the nation, they remained skeptical.

"After three years of this war, everything feels the same," one of the men told CNN.

"Rotten Access"

Speaking to CNN on Thursday, Ukraine's commander-in-chief Oleksandr Sirsky acknowledged that low morale is still a problem and said that raising it is a "very important part" of his job.

"Operation Kursk ... significantly improved the morale not only of the military, but also of the entire Ukrainian population," he said.

He said he regularly went to the front to meet the soldiers there and do what he could to make them feel better.

"We understand each other no matter who I talk to, whether it's an ordinary soldier for example, or a brigade commander or a battalion commander... I know all the problems that our soldiers, soldiers and officers have. experience. The front line is my life,” he said.

And Horecki – an officer specially trained to provide moral and psychological support to soldiers – is part of the plan to boost morale.

During a recent leave in Kiev, Khoretsky told CNN that while his role has been around for a while, it mostly consists of paperwork. Now he spends a lot more time with his unit, checking in, making sure they don't burn out. Not that his help is always appreciated.

"They have this idea that I'm for tapering that will make them do thousands of tests and then tell them they're sick, so I'm trying to break down the barriers," he said, adding that small distractions can prevent a downward spiral.

In the monotony of war, any break from routine can help, he said. This can include washing in a real shower, getting a haircut or going for a swim in a lake.

"It's a small thing, but it gets them out of their routine for half a day, makes them happy and they can go back to their positions a little more relaxed," Horecki explained.

Even officers with many years of experience find the situation in the east difficult.

Some, like Dima, move to places far from the front lines. He said his decision to leave the battlefield was mostly due to disagreements with the new commander.

It's also an increasingly common occurrence, several police officers told CNN.

The ranks of Dima's battalion grew thinner and thinner until the unit disappeared.

They never got enough reinforcements, Dima says, something he blames squarely on the government and its reluctance to recruit more people.

The battalion suffered painful losses in the past year, fighting on multiple front lines before being sent to Pokrovsk without any rest. Dima saw so many of his men killed and wounded that he was dumbfounded.

However, he told CNN that he is determined to return to the front lines, but he will make one change first.

"Now I have made a decision that I will stop getting emotionally attached to people. It is a rotten approach, but it is the most sensible one,” he said.