Maidan Square in central Kyiv gave its name to the 2014 pro-Western revolution that toppled Ukraine's Moscow-aligned President Viktor Yanukovych and, inadvertently, prompted a new and more violent phase in Russia's decades-long campaign to contain and smother Ukrainian independence and democracy.
In the square's grass banks, once covered by the encampment of protesters, there are now rows upon rows of flags planted in the snow-covered soil. Each one represents a Ukrainian service member -- or a foreign volunteer -- killed defending the country across four years of full-scale war.
Ukrainian President Volodymyr Zelenskyy said earlier this month that 55,000 Ukrainian soldiers are known to have been killed in almost four years of defending against Russia's full-scale invasion of the country. The true toll of the war may never be known. Neither side regularly publishes casualty figures, and both have reason to distort them.
They, and many of what Zelenskyy said is a "large number of people" registered as missing, will be added to the Ukrainian pantheon of military dead, ever-swelling -- gradually since 2014 but rapidly after 2022 -- as Kyiv's troops sought to push back Russia's invasion.
Ukraine had around 980,000 people in uniform as of January 2025, according to Zelenskyy. A handful, dotted around some of the hottest portions of the front, told ABC News of their exhaustion and resolve on the eve of the invasion's fourth anniversary.
Kuper -- who asked to be identified only by his call sign -- is a member of the communications unit of the 14th Chervona Kalyna Brigade, an assault formation and part of the National Guard of Ukraine. The unit is currently deployed to the Pokrovsk area -- one of the most intense portions of the front and the focus of a grinding Russian offensive since the summer of 2024.
"The situation is really hard," he told ABC News via phone from a position behind the so-called "zero line," where the fighting is unceasing.
"The Russians are paying a great cost in the Pokrovsk direction," Kuper said. "This summer, it's going to be two years that they're fighting for the city -- just one city."
"Around the city of Pokrovsk and other cities in this direction, all the fields, all the little pieces of forests -- everything is covered with Russian bodies," he said. "They are well-known for not collecting the corpses of fallen comrades."
Kuper -- a rock musician and journalist before the war -- joined the military in 2023. His unit has been active in the ill-fated 2023 Ukrainian counteroffensive in the southern Zaporizhzhia region and later in Donetsk for the defense of Pokrovsk and Myrnohrad.
"Everyone is tired -- very tired," Kuper said. But all are driven by the fear of a Russian victory. "All they care about is wiping out our country, and our country is our home," Kuper said.
"We don't have anywhere to go," he added.
The capture of Donetsk and Luhansk -- which together form the Donbas area -- is the foremost Kremlin goal. To achieve it, Russian forces must battle across an industrial landscape dotted with urban centers, hills and valleys -- all offering the Ukrainians potent defensive positions. Several of those who spoke to ABC News are fighting in this region.
The Donetsk "fortress belt" of interlinked fortified cities has contained the Russian army since 2014, and Ukrainian commanders and politicians are loath to surrender it. Moscow has demanded that Kyiv withdraw its troops from the partially occupied region as part of a potential peace deal. Kyiv has repeatedly refused.
Naruto -- his call sign -- is a 23-year-old sergeant also with the 14th Chervona Kalyna Brigade, serving in an intelligence and reconnaissance unit in the Pokrovsk area. Each day, he told ABC News, "I wake up, smoke a cigarette, put on my armor and helmet, and go out to conduct surveillance so the enemy can't break through our defense lines."
Naruto is three years into his military career. Before the war, he ran his own car service business. "This job is hard and has many stressors. Day by day, it takes a heavier emotional toll," he said.
Drones dominate the fighting on both sides, Naruto said -- whether for supply and logistics, reconnaissance or direct combat. Russian guided bombs destroy Ukrainian shelters and fortifications, he said, after which Russian FPV drones move in for the kill.
The mauled Russian army now edging westward around Pokrovsk is a patchwork of different units with different capabilities, Kuper said, "kind of like a salad."
"The infantry is very poorly prepared," he said. But Russian drone units, he continued, have "a lot of well prepared specialists with good equipment. And they try not to use them in these meat grinder attacks."
Particularly feared is Russia's "Rubicon" unit, which are engaged in strikes on supply routes and positions deep behind the Ukrainian lines.
The Russian attrition rate is high, Kuper said, comparing Moscow's army degradation to a sports team with multiple squads -- an A team, B team, C team and so on. "I think they are at least in the middle of the alphabet by now," he said.
For its part, the Russian Defense Ministry has framed its attritional advance as an inevitability. Each day, the ministry releases the names of small -- often destroyed -- settlements it claims to have captured.
The Pokrovsk battlefield includes neighboring Myrnohrad, less than 3 miles to the east. There, too, "the situation is hard," Maj. Bohdan Yanush -- call sign Fritz -- of the 79th Air Assault Brigade told ABC News via text message.
"We all want peace, but at what price? Give up our territories? No, this is our land, we are fighting for it," Yanush said. "Аll wars were started and finished by diplomats -- it's their job. Our job is to keep fighting."
The Russians are "engaging our positions 24/7" and bombarding Ukrainian supply routes with all kinds of munitions, Yanush said.
That strain on resupply and reinforcement is the main problem facing troops in Myrnohrad, Yanush added. Ukrainian forces are now largely reliant on resupply by large drones -- such as the "Vampire" heavy lift hexacopter -- he said.
Maj. Myroslav Kryvoruchko of the 38th Marine Brigade, also fighting in and around Myrnohrad, told ABC News that Ukrainian supply routes remain operational, though under constant threat.
Kryvoruchko described the urban battlefield as fluid. "Control can shift block by block, or even building by building," he said, making it hard to accurately chart areas of control on maps.
Russian soldiers are constantly attempting to slip into the city's ruins unnoticed in small groups, Ukrainians who spoke to ABC News said. The Russian assault teams "often exploit poor weather conditions, darkness or limited visibility" as cover for their infiltration efforts, Kryvoruchko said.
Ukrainian defenders, he added, stay in their positions until their cover is destroyed, then move to defend new locations. Russian forces claim destroyed areas as captured territory, "but in reality it's just destroyed buildings without cover," Yanush said.
The Russian attacks keep coming despite their many setbacks, Yanush said. The Russians' sudden and widespread disconnection from the Starlink network, for example, prompted "panic on their radios" and a halt to assault operations, he recalled.
But the pause lasted at best a few days, the Ukrainian troops who spoke with ABC News said, before the Russians resumed their attacks.
The Russian units are reliant on a constant influx of replacements to maintain momentum, the Ukrainian soldiers told ABC News. Military analysts have generally come to the same conclusion.
Naruto said of the Russians, "I can't even call them soldiers. They are wild beasts who have never seen anything in this world. They came here to rob, kill, and rape us. These beasts deserve only one thing -- elimination."
"Russia is a copy of North Korea: no freedom of speech, no free elections, nothing. Russia is a big swamp that needs to be destroyed and turned into a turnip farm," he said. "There can't be any kind of peace with them, but if such a thing happens, I would build a wall to separate us from Russia and Belarus."
Among the most dangerous Russian thrusts are the drive toward the southern city of Zaporizhzhia, which had a pre-war population of 710,052 and serves as the gateway to much of the southern front. In September, Russian forces began a relatively rapid advance in the farmlands to the east of the city, advancing up to six miles in places, according to Ukrainian military officials.
Among the units dispatched to stem the tide there was the 225th Separate Assault Regiment, engaging the Russians around the small city of Huliaipole. The relatively flat, sparsely populated landscape of southern Ukraine is starkly different to the hilly, industrial Donetsk region. But the nature of the fighting is similar.
Maj. Oleh Shyriaiev of the 225th told ABC News in a video interview, via an English translator, from close to the front that the Russians have "hit some barriers" in trying to penetrate deeper toward Zaporizhzhia. "They are desperately trying to infiltrate their infantry in between our positions," he said.
"Nothing has changed in their tactics, except for the number of casualties that they are suffering," Shyriaiev said, adding that the 225th counts only Russian casualties they can visually confirm -- often with the help of UAVs. "They have lost two complete regiments in the Huliaipole direction, and they have brought in two new brigades."
Shyriaiev said his unit is facing the Russian 5th Combined Arms Army. "Their infantry personnel were completely wiped out and they have replaced them with two brigades that had not been reconstituted properly, because they need to keep trying to move forward," he said.
"They have serious problems with equipment," Shyriaiev said of the Russian attackers. "They are increasingly using civilian cars -- regular cars, not armored vehicles -- and there have even been cases where they have used horses to try and move, and also motorcycles ... 90% of armored vehicles that approach the front lines, we just destroy them."
Shyriaiev is on his third stint in the Ukrainian military, having completed his mandatory service in 2008 and later fighting against Russian forces and their local separatist allies in the Donbas after 2014. He re-joined in the opening days of the 2022 full-scale invasion.
Shyriaiev said he is not thinking about his post-war life, "because I do not believe that the war will stop anytime soon."
If it does, though, Shyriaiev said he intends to stay in the military and pass on his experience. "I do not see any other future for myself, because this is the only thing that I know how to do -- fighting in a war," he said.
On the Pokrovsk front, Kuper said he keeps abreast of the U.S.-led peace negotiations. But after a while, he said, the news cycle becomes "white noise."
The possibilities of post-war life, though, is a favored topic of conversation within his unit. "Everyone has plans," Kuper said.
Kuper said that his pre-war life is gone, its routines and relationships broken and scattered by four years of war. Kuper hopes to return to playing music and plans to leave the military, he said.
In the meantime, Kuper said he snatches moments of rest when he can -- video games and his guitar are favored escapes. But sometimes, he said, "when you're really tired, a good way to relax is to stay in silence. To feel the calm."
Naruto said he can occasionally meet his wife in the city of Dnipro -- less than 100 miles from the front -- for a short holiday. "For two to three days, we live only for each other," he said.
He also sees little prospect of an end to the fighting. "We don't see the war ending this year," he said.
Talk of security guarantees "sounds great, but nobody follows agreements," he added. "Support with weapons and intelligence is good, but nobody hears our request to 'close the sky' and stop the suffering of women and children. Nobody reacts to the deaths of civilians and children."