LONDON — When the players of the Belarus Free Theater began working on “Dogs of Europe” three years ago, they thought it was a play about a dystopia.

Set in 2049, it imagines the continent cut in half by a wall. On one side sits a Russian superstate, where a dictator has eliminated almost all opposition, and where people cannot speak their native languages or even perform folk dances. On the other side sits a Europe that failed to realize the Russian threat, or stop it from absorbing Belarus, Ukraine, the Baltic States and beyond.

Yet at a rehearsal in London last month the day before Russia invaded Ukraine, the play’s nightmare world didn’t feel so far-fetched.

Maryna Yakubovich, an actor in the production, which opens Thursday at the Barbican theater in London, said that rehearsing the play had sometimes felt like a premonition. “It’s, like, ‘Oh my God, it’s started to happen,” she said.

Natalia Kaliada, one of the Belarus Free Theater’s founders, said that when she and her husband, Nicolai Khalezin, decided to stage the play, they thought it would be a “warning shot” about the dangers of undemocratic leaders left unchecked. But planned performances in London and New York in 2020 were postponed because of the coronavirus pandemic. Now that warning shot appears to be too late.

As the war in Ukraine enters its third week, the Belarus Free Theater’s performance may seem accidentally timely. But it is only the company’s latest attempt in its 17-year existence to warn about rising authoritarianism in Eastern Europe.

The company knows those dangers all too well. Since forming in 2005, it has faced repression in Belarus, which is ruled by President Aleksandr G. Lukashenko, who is known as “Europe’s last dictator” in part for his government’s clampdown on opposition and its stifling of free expression. The troupe has long been effectively banned from performing in Belarus, but it continued to do so in secret venues in Minsk, the capital, even after Kaliada and Khalezin were forced into exile more than a decade ago. The couple settled in London — where they developed close ties to theaters including the Young Vic and the Almeida — but continued rehearsing with actors in Belarus via Skype.

Those clandestine shows, in venues including a converted car garage that once belonged to the American Embassy, also won the troupe high-profile supporters in the United States. In 2015, The New York Times’s chief theater critic, Ben Brantley, visited the company in Minsk, and praised its “spirit of defiant, exultant fraternity” adding that this was something “you rarely find among the young these days in money-driven, shockproof Manhattan.”

Now, even that window to perform in Minsk has closed. The theater’s entire 16-member acting troupe fled Belarus last year to avoid potential jail time for opposing Lukashenko’s regime.

The Belarus Free Theater was now homeless, Kaliada said. “We are refugees.”

She added that she had hoped its members would be granted asylum in Britain, so they could set up a refugee-led theater there, but the process can take years and asylum applicants are almost always banned from working. After its four-performance run at the Barbican, the company would most likely set up base in Warsaw, a city with numerous refugees from both Belarus and Ukraine, Kaliada said, but added that a final decision had not yet been made.

The company’s finances are precarious, Kaliada said, though she had a clear vision for the future. As well as finding a performance space, the company would establish a school where its members could give acting classes to refugee children, she said. All of its future plays would be live-streamed back to Belarus, so the company would keep reaching people there.

“It’s a pretty tough time,” Kaliada said. “We’re trying to solve many issues at once.”

The company’s experiences over the past two years show how quickly fortunes can change in Eastern Europe. In August 2020, Belarus — a country of some nine million people — looked on the verge of a turning point after Lukashenko declared victory in a vote widely dismissed as fraudulent, leading to mass street protests. It was a “beautiful, powerful,” moment, Kaliada said: It felt like her country was waking from a bad dream, she said.

Then a brutal police crackdown against the protesters brought those hopes to an end.

Several of the company’s actors were arrested during the period of repression around the election. Sveta Sugako, the company’s production manager, said she spent five days in prison in a tiny cell with 35 other women. None of them were given any food or drinking water for three days, she added. After Sugako refused to sign a confession saying she had taken part in the demonstrations, a police officer grabbed her and choked her, she said.

Sugako said she had not wanted to leave Belarus, even after that experience. “I was ready to sit and wait in jail,” she said, but other Belarus Free Theater members persuaded her to go, pointing out that the company had no future if all of its actors were behind bars.

At the recent rehearsal in London, the atmosphere was muted. When not performing, the actors checked their phones for news from home.

“Of course we’ve left Belarus, physically,” Yakubovich said, “but mentally we’re still there.” The news was “never good,” she added.

Then there was the situation in Ukraine to contend with. Russia was using Belarus as a staging ground for its looming invasion, and many company members had fled Belarus via Ukraine, or had friends and relatives there. Marichka Marczyk, a Ukrainian musician who performs a live soundtrack for the show, said she had just received a text message from her brother in Kyiv, Ukraine, with instructions if he was killed in the fighting: “Burn my body/scatter the ashes,” he wrote.

Roman Liubyi, a Ukrainian video animator working on the production, said his wife and 5-year-old daughter were also in Kyiv. He was considering leaving rehearsals to get them out if a war began, he said, and then joining any fight against Russia.

While her colleagues grappled with the news, Kaliada, a founder of the company, watched from the sidelines.

She could picture Russia absorbing both Belarus and Ukraine, she said, just as it did in “Dogs of Europe.” Yet even if the company faced many years of exile, “Belarus is with us,” she said. “We will have a home.”