“We’re so used to it by now, we no longer pay much attention,” Ms. Bondarenko, 76, said as she pointed to a nearby crater left by a Russian shell in the morning. “It’s been going on for months. When is it going to end?”

As they sat outside their apartment block on a frigid day, chatting and enjoying some fresh air, Russian shells came closer and closer, devastating what remains of this eastern Ukrainian city of Bakhmut.

Ukrainian troops fortified the neighborhood by emplacing concrete slabs at an intersection nearby. Finally, three tanks arrived, their turrets bearing blue-and-yellow flags. Machine-gun fire, along with the thumps of artillery, could be heard in the distance.

“It’s probably never going to end,” replied Ms. Shilkova, 75.

No heating, power, or running water has been available in their apartments for months. The only food available comes from volunteers, Bondarenko said. “That is how we live,” she said. It’s a humanitarian catastrophe.

With the exception of Bakhmut, the battle for Ukraine has become a focal point for troops, tanks, and artillery in the last 10 months; Bakhmut has become the new frontier in the conflict. Prigozhin, the proprietor of Wagner, has recruited thousands of Russian prisoners for the assault on Bakhmut. In addition to the 300,000 troops that Moscow has supposedly mobilized since October, some new forces have also been sent.

Prigozhin, a close ally of Vladimir Putin, the Russian president, and founder of the military contractor Prigozhin companies, has heavily invested in the future of Bakhmut because he criticized regular military commanders as incompetent, praised Wagner as Russia’s most significant fighting force, and received generous state funding after promising to conquer Ukrainian territory months ago.

General Sergey Surovikin, the new commander of Russian forces in Ukraine, also has a lot at stake here. In early October, General Surovikin cited the need to transfer troops from Kherson to other locations to justify the withdrawal.

“Surovikin must show some sort of victory somewhere since his appointment,” said Fedir Venislavskiy, a member of the Ukrainian parliament’s national security, defense and intelligence committee. “What the Russian military and political leadership desire very much is a capture of Bakhmut. And that’s why both Surovikin and Prigozhin are throwing all their forces at it.”

The Ukrainian calculation is not purely military in nature. If Bakhmut were to fall, Chasiv Yar, located just to the west, would provide an excellent line of defense for the Ukrainian-controlled 40% of the Donetsk region that Russia claims as its own.

However, according to Col. Gen. Oleksandr Syrsky, commander of Ukrainian land forces, Bakhmut doesn’t have military significance but has a psychological one.

The fall of Bakhmut would signal that Ukraine has lost the initiative after four months of steady advances, raising Russian morale and making future Donetsk and Luhansk offensives more difficult. That is why in the last three weeks, Ukraine has sent large numbers of fresh troops and equipment to the area.

Ukraine tried to avoid set-piece battles throughout the battle, knowing that this warfare favored Russia.

“Some of the things that make us strong, such as independence, initiative, the ability to act even when without clear orders, can also become our weaknesses when many units are in the same place, and each has their own view,” said Mykola Volokhov, commander of the Terra drone-reconnaissance unit that, among other Ukrainian forces, was relocated to Bakhmut from the Kherson front this month. “The outcome in Bakhmut will depend on the ability of our forces to achieve coordination.”

Because of poor weather conditions, the Ukrainian offensive on the Kreminna-Svatove front to the north has been stalled, making unpaved roads impassable. A sustained drop in temperatures, Ukrainian commanders believe, might freeze the ground, allowing Ukrainian forces to resume their eastward push.

Russian advances in Bakhmut, if they come first, would relieve the Ukrainian pressure on Kreminna and Svatove. But, conversely, if successful, that would endanger the rear of Russian troops attacking Bakhmut, forcing them to retreat.

Heavy artillery fire was used by the Russians in an attempt to capture Bakhmut over the summer, reducing numerous urban areas to rubble before infantry assaults. This approach was used to seize Mariupol in May and Severodonetsk and Lysychansk in June and July, as well as months of fierce fighting near Bakhmut, which have gained only limited amounts of ground.

A Ukrainian Akatsiya 152 mm howitzer battery commander, who identifies himself as Captain, says that Russian fire has been less intense in Bakhmut these days than it was on the Kherson front before his recent redeployment there.

Standing behind him, a U.S.-made M109 Paladin howitzer from another brigade roared into a field and began firing. The Captain suggested that the Russians were running out of ammunition.

Ukrainian troops face a dangerous new threat from Russian mercenaries hired by a private Russian military company. The company, founded by a Russian oligarch, reportedly uses former Russian soldiers to lead a group of mercenaries into battle. The mercenaries are said to have been recruited from prisons, where inmates face execution for desertion if they flee and are promised amnesty if they survive six months in Ukraine. 

These mercenaries, better equipped and more motivated than Russian troops on other front lines, have at times been successful—but at a high cost.

A cockroach infestation is the best way to describe the situation on the frontlines of eastern Ukraine, according to Yuri, a soldier is permitted to only give his first name or call sign. 

“We shoot them, and they keep coming back, like cockroaches. The fields all around us stink because of their corpses, but there is still one wave coming after another.”

Ukrainian soldiers recently transported a body bag containing a slain comrade across the Bakhmutka River in the city, incurring casualties as well.

A Russian shell exploded on a hillside near an improvised medical facility, followed moments later by volleys of gunfire. After the field hospital in Bakhmut was repeatedly shelled and closed down, three more plastic bags were piled up in the driveway, awaiting transport.

According to Sergiy Stakhovsky, a Ukrainian tennis player and winemaker fighting in Bakhmut, Russians are emptying their prisons and sending their worst to die here while losing some of our best. It is not at all a fair trade,” he said.

Despite Russian offensives aiming to encircle Bakhmut, at least three crucial supply roads remain under Ukrainian control. Military traffic moves in and out of Bakhmut 24 hours a day, supplying ammunition, fuel, and meals to the front lines and transferring soldiers from the fighting positions to the rear outposts.

According to Ukrainian officials, roughly one-tenth of Bakhmut’s prewar civilian population remains. The zhduny, Russian sympathizers who anticipate a Russian occupation, as well as people who are too poor, old, or sick to leave, and Ukrainians who believe in the Ukrainian army’s ability to defend the city and eventually expel the Russians, are all present.

Officials opened a Resilience Center in an abandoned store earlier this month where Tetiana Shcherbak, a nurse, runs a program. Volunteers distribute tea, coffee, hot food, and medicines to local residents.

Visitors can charge their phones and other devices using a generator, and a Wi-Fi service lets them connect with family and friends. In addition, a TV on the wall broadcasts Ukrainian news to those who often have no clue what’s going on in the war, providing information and support.

Psychological help is critical in Bakhmut, according to Ms. Shcherbak. She stated that survivors can speak to one another, watch TV news, and consequently survive. Shcherbak has no intention of leaving. 

“Of course Bakhmut will hold out,” she said tearfully. “We believe in our soldiers, in our eagles, in our falcons. We’re Ukrainian.”