STANYTSIA LUHANSKA, Ukraine — People pass the bare-bones checkpoint dragging wheeled suitcases along the muddy pavement, crossing one of the starkest political divides in Europe today.
In pale winter sunshine on Sunday afternoon, Gleb Yegorov, 17, made his way into Ukraine after navigating a half-mile buffer zone and then crossing a pedestrian bridge strung over a ravine. Artillery boomed in the distance.
Behind him was the Russian-backed separatist enclave known as the Luhansk People’s Republic, which he said he was fleeing to avoid the draft. He barely made it out, he said, after an eight-hour interrogation on the separatist side of the crossing, and would never go back.
“There’s no future for me there,” he said. “They send boys to the front and don’t think about it if they die.”
For years, the Luhansk People’s Republic and its fellow breakaway Ukrainian enclave, the Donetsk People’s Republic, were largely ignored. They were just two odd little political entities, Stalinist throwbacks with internal politics too esoteric to merit much attention from the outside world.
But now that the biggest war in Europe in decades may hinge on them, it sometimes seems as if Luhansk and Donetsk are all anyone is thinking about.
With Ukraine surrounded by Russian forces, Western governments warn that Moscow may use the two Russian-backed republics as the stage for a “false flag” attack on ethnic Russian civilians — and then cite it as justification when they storm across the border.
The divide between these mini-states and Ukraine is reminiscent of the Berlin Wall — that is, a separation that grew not out of language or ethnicity but from Cold War-style politics. On one side of the roughly 250-mile frontline is Ukraine, a Western-looking nation aspiring to integrate with European democracies. On the other are about 3.5 million people living in virtual police states.
The worry is that these territories will become the setting for a catastrophe, whether staged or accidental, that could lead to far wider violence. A stray shell, for example, might hit a residential building, or there could be a terrorist attack on fleeing refugees. Whatever the situation, Ukraine would be blamed, and Russia would have a pretext to invade.
Russia, despite repeated accusations from the West, says that it has no intention of invading, and that it simply wants its legitimate geopolitical interests respected.
On Sunday evening, the Ukrainian military issued a statement saying the Russian-backed separatists in the Luhansk region had opened fire with heavy artillery on their own capital city “with the goal of blaming the Ukrainian military.”
“In the absence of any aggressive action from the Ukrainian defenders, the occupiers themselves are blowing up infrastructure in the occupied territories and firing chaotically on towns,” the statement said. Russian news agencies reported artillery strikes in the area. There were no immediate reports of casualties.
While attacking one’s own side to blame an enemy may seem particularly sinister, it would not be the first time it has happened over the eight-year history of the two enclaves.
Analysts have suspected numerous violent events to be false-flag attacks. And insider violence by Russia’s security services or local proxies has been an integral aspect of the republics’ history for years, according to the Ukrainian intelligence services and public statements by comrades of some of those killed.
In recent days, both sides along the eastern Ukrainian front have been making ominous predictions about a mass-casualty event somewhere out in the mining and farming villages — and they are blaming each other even before it has happened.
“The Russian Army and special services are preparing a terrorist attack, the victims of which should be peaceful residents,” the commander of the Ukrainian armed forces, Valery Zaluzhny, warned in a statement over the weekend. “The enemy is seeking to use this as justification to bring in the Russian Army as ‘peacekeepers.’”
On Sunday, the Ukrainian interior ministry released a statement saying the information ministry in the Donetsk People’s Republic was prepositioning film crews at sites of supposedly impending Ukrainian drone strikes. “The purpose of such actions is to demonize the Ukrainian military,” it said.
The Luhansk People’s Republic, meanwhile, said its security service — known as the M.G.B., one version of the name used by the K.G.B. in the Soviet Union — had discovered a radio-controlled car bomb along the route traveled by buses carrying evacuees. The claim could not be independently verified.
Raising tensions, the people’s republics have said they plan to evacuate 700,000 women and children because the Ukrainian Army plans an attack. Western governments have scoffed at the idea that Ukraine would launch an attack just as Russia has amassed, by the most recent U.S. estimates, 190,000 troops near its borders.
Residents of the separatist enclaves who evacuated to Russia had starkly different views of the escalating violence along the frontline, accusing Ukraine of firing artillery into towns on their side.
Ukrainian soldiers “are standing just six miles away from us, and we can hear them very well,” said Lyudmila N. Zueva, 63, as she entered Russia at the Matveev Kurgan border point over the weekend.
The enclaves broke away in 2014, and after they did, to drive into these regions deep in Eastern Europe was to journey into a realm seemingly apart from the contemporary world. Pontoon bridges have been put up beside blown-up highways that trace a route of half-abandoned towns and the sprawling hulks of ruined factories. Overhead, no commercial planes are to be seen. Flights ended in 2014 after a civilian airliner was shot down.
What happens in the republics is something of a black box.
Gaining entry for international journalists can be challenging. And only one international group, an Organization for Security and Cooperation in Europe monitoring mission with a weak mandate, has observers on the ground.
But some information has emerged.
The military and civilian leadership has seesawed between Russian citizens with suspected ties to intelligence agencies and local Ukrainians with modest résumés, and it has been upended by a series of violent purges. At various times, senior positions have been held by the owner of a dog behavior school, a man who performed as Santa Claus at a mall, the operator of a Ponzi scheme and a reputed organized crime boss.
As they were sidelined and replaced, separatist leaders blamed the Ukrainian military for assassinations and ambushes that officials in Kyiv, Ukraine’s capital, said were entirely homegrown affairs.
Perhaps the most prominent killing was that of the president of the Donetsk People’s Republic, Aleksandr Zakharchenko, who died in a restaurant bombing in 2018 that each side pinned on the other.
But other bloody episodes occurred even before that, among them one in which several separatist paramilitary commanders and their supporters were killed in ambushes in 2015. The victim of one attack was a man named Aleksei B. Mozgovoi, a pro-Russian warlord nicknamed “the Brain” whose five bodyguards proved of little avail. Mr. Mozgovoi’s press secretary, too, was killed.
One of his comrades in arms, Pavel L. Dryomov, made a video address to President Vladimir V. Putin of Russia, blaming the pro-Russian side for the internecine violence.
“Is this why we intervened? Is this why we died?” he asked.
Mr. Dryomov was soon also killed. The Luhansk People’s Republic blamed Ukrainian special forces.
Ukraine’s interior ministry estimated that 200 people died in the purges and said Russia’s military intelligence agency, the G.R.U., had organized the attacks.
The politics of the enclaves are a blend of Russian imperialism and nostalgia for the Soviet Union. Hammer-and-sickle flags are commonly flown. In government offices, officials hang portraits of Stalin and Orthodox Christian icons.
“When it all started back then, I had a feeling of disconnect with reality,” said Maria Paseka, who left the Luhansk People’s Republic and moved to the government-controlled side last August. “The puzzle didn’t fit together. It felt like everyone around had been told something that I didn’t know about.”
In Ukraine, Ms. Paseka admitted, “there are things to improve, like the government, salaries, prices, living standards. But it’s clear to me where I live now, and that we move to Europe, not falling back into prehistoric times with Russia.”
The order last week by the new leader of the Donetsk People’s Republic, Denis Pushilin, to evacuate hundreds of thousands of women and children was seen as a particularly ominous signal.
Mr. Pushilin, who stepped in after the assassination of Mr. Zakharchenko, said he anticipated a Ukrainian attack that would kill civilians.
While thousands of people have boarded buses and evacuated to Russia, some have taken the opportunity to flee West, crossing into Ukraine at the only operating checkpoint: the footbridge and a roughly mile-long stretch of pavement here, where a cease-fire is generally observed to allow civilians to cross.
On Saturday, Natalia Kasheyeva, 33, a lawyer, rolled a Day-Glo yellow suitcase across while leading her two daughters, whom she was sending to their grandparents’ to get away from the violence.
“You feel the pressure,” she said of life in the Luhansk People’s Republic.
Mr. Yegorov, who left to avoid the draft, his green eyes squinting in the late-afternoon sunshine, said he had been living with his grandfather but would now live with his mother in Kyiv. He said he saw right through what he called the phony, Communist-revival politics of the leadership.
“Nobody I know,” he said, “wants to fight for the Luhansk People’s Republic.”
Maria Varenikova contributed reporting from Kyiv, Ukraine, and Ivan Nechepurenko from the Matveev Kurgan border post in Russia.