AMSTERDAM.- Just days after the invasion of Ukraine, Olga Smirnova, one of Russia’s most important ballerinas, posted an emotional statement on Telegram, the messaging app. “I am against war with all the fibers of my soul,” she wrote.

“I never thought I would be ashamed of Russia,” she added, “but now I feel that a line has been drawn that separates the before and the after.”

That’s certainly been true for Smirnova, 30. As the war got worse, and dissent in Russia was ruthlessly quashed, Smirnova, who had gone to Dubai to recover from a knee injury, realized that she could no longer return home. “If I were to go back to Russia, I would have to completely change my opinion, the way I felt about the war,” Smirnova said in a recent interview in Amsterdam, adding that returning would be, “quite frankly, dangerous.”

So she left the Bolshoi, the storied company whose name is synonymous with ballet, with its gilded theaters just blocks from the Kremlin, uprooted her life and moved to Amsterdam, where she joined the Dutch National Ballet.

The departure of Smirnova is a blow to the pride of a nation where, since the days of the czars, ballet has had an outsize importance as a national treasure, a leading cultural export and tool of soft power. Her move is one of the most visible symbols of how Russia’s invasion of Ukraine has upended ballet, as prominent artists shun Russia’s storied dance companies; theaters in the West cancel performances by the Bolshoi and the Mariinsky; and dance in Russia, which had opened up to the world in the decades since the collapse of the Soviet Union, seems to be turning inward again.

“We’re going back to the Cold War,” said Ted Brandsen, the artistic director of Dutch National Ballet and Smirnova’s new boss, invoking a time notable for the defections of Soviet dance stars including Rudolf Nureyev, Mikhail Baryshnikov and Natalia Makarova. Brandsen said Russian dancers were contacting him daily saying, “I can’t be myself as an artist in this country.”

Simon Morrison, a Princeton professor and historian of the Bolshoi, said that in recent years the Bolshoi had become “more liberal, international, cosmopolitan, more experimental,” even staging a ballet about Nureyev that touched on his homosexuality. Now, he said, it was looking at “an impoverishment of the repertoire.”

Ballet in Russia is something of a national pastime — a cultural jewel, but also the focus of intense emotion and close scrutiny by its discerning audiences, even if it’s less popular with the pop-culture obsessed young. Ballet is “beloved by Russian people like no other place in the world,” said David Hallberg, who in 2011 became the first American dancer to become a principal at the Bolshoi, half a century after Nureyev became the first major Soviet dancer to defect to the West.

Hallberg said Smirnova was “very brave” to leave the Bolshoi, given she wasn’t just leaving a company, but an institution that “was in her DNA.”

Smirnova is not the only high-profile artist to leave Russia. On the day war began, Alexei Ratmansky, ballet’s preeminent choreographer and a former artistic director of the Bolshoi, was in Moscow rehearsing a new work. He immediately got a flight back home to New York, where he is artist in residence at American Ballet Theater, saying he was unlikely to return to Russia “if Putin is still president.”

Laurent Hilaire, the French director of the Stanislavsky and Nemirovich-Danchenko Ballet in Moscow resigned days after the war began. And a host of dancers, mostly foreign, have left too, including Xander Parish, who is British; Jacopo Tissi, who is Italian; and David Motta Soares and Victor Caixeta, who are Brazilian. Caixeta, a rising soloist, is now in Amsterdam partnering Smirnova. The pair are scheduled to make their debut in “Raymonda,” a classic of Russian ballet, on Saturday.

Since Russia’s invasion began, many European governments have ordered their cultural institutions, including dance companies, not to work with Russian state bodies like the Mariinsky or the Bolshoi. The Dutch National Ballet has canceled a visit by the Mariinsky, pulled out of a ballet festival in St. Petersburg and stopped collaborating with the Moscow International Ballet Competition, scheduled to take place at the Bolshoi in June.

Works by several prominent Western choreographers may disappear from Russian stages, as those who control the rights to their ballets suspend collaboration with Russian companies. Nicole Cornell, the director of the George Balanchine Trust, which holds the rights to the choreographer’s work, said in an email that it had “paused all future licensing conversations” with Russian companies. And Jean-Christophe Maillot, a French choreographer and director of Les Ballets de Monte Carlo, said in an email that he had asked the Bolshoi to suspend performances of his “The Taming of the Shrew,” but that its general director, Vladimir Urin, had refused. “These conditions obviously make it difficult to resume a collaboration with the Bolshoi,” Maillot said.

Change could be coming within Russia too. At the end of March, President Vladimir Putin raised the idea of uniting the Bolshoi with the Mariinsky — Russia’s other main company, based in St. Petersburg — under the leadership of conductor Valery Gergiev, the artistic and general director of the Mariinsky, a close ally of Putin who has seen his Western career evaporate since the war began. Bringing the fierce rivals together under a common directorship would take Russian ballet back to the days of the czars.

Morrison said in a telephone interview that the move was likely a way of pressuring Urin, the Bolshoi’s general director, who signed an anti-war letter in the early days of the invasion, to toe the line and to ensure there would be no further high-profile departures or anti-war commentary from his company. Putin “certainly has bigger problems than the Bolshoi,” Morrison said, “but he understands the nationalistic potency of culture.”

Urin seemed to get the message. On April 2, the Bolshoi performed Aram Khachaturian’s “Spartacus,” a 1956 ballet about “the liberation of the oppressed,” Morrison said, meant to chime with “the ideological principles of the Soviet Union.” The Bolshoi said in a news release that proceeds from the show would be used to help the families of Russian soldiers who died in the “special operation” in Ukraine, as the invasion is known in Russia.

Representatives of the Bolshoi, Mariinsky and Vaganova Ballet Academy declined or did not reply to interview requests for this article.

In Amsterdam, Smirnova said her own future was “cloudy,” and she wouldn’t want to guess what was in store for Russian ballet. But, she said, it seemed there would be “a lot fewer invitations for international choreographers and a lot fewer stagings of international works.” That means Russian dancers would have fewer opportunities to develop, even if “the golden collection of the Bolshoi’s work” — its classical ballets — would remain in place.

Smirnova’s own family highlights the growing gap between Russia and the West. She didn’t tell her mother about her move to Amsterdam until after she had signed the contract. “For her, the Bolshoi Theater is the pinnacle,” Smirnova said. “She couldn’t understand why I would change.”

Despite her high profile, Smirnova had not had to deal with politics before in her career. She grew up in St. Petersburg in “a very ordinary family that had nothing to do with the art form,” as she told The Daily Telegraph in 2013. But after joining the famed Vaganova academy in her home city, she appeared destined for stardom, with ballet writers often struggling to find metaphors strong enough to describe her.

Brandsen said he first saw her dance while visiting her graduating class. “There was this creature completely unlike any young dancer I had seen,” he said. “I was completely overwhelmed with her talent and her presence.”

In 2011, Smirnova joined the Bolshoi when Sergei Filin, then its artistic director, offered her a contract. (In 2013, Filin was the victim of an acid attack that shocked the world, but also highlighted the intensity of Russia’s dance culture.) The Bolshoi’s tours helped make Smirnova an international star. In 2013, when she danced at the Royal Opera House in London, at 21, Roslyn Sulcas described her in The New York Times as “a ballerina whose every movement feels luminously right and true.” When she danced the “Diamonds” prima ballerina role in George Balanchine’s “Jewels” in an international performance at the Lincoln Center Festival in 2017, Alastair Macaulay wrote in the Times that her “illustrious performance” was “just what festivals should be about.”

There was relatively little coverage of Smirnova’s departure in Russian state media, but the strength of feeling around her can be seen in comments on Russian ballet forums: One user of the Passion Ballet forum, for example, last month wrote “good riddance” to Smirnova, adding, “this freshly frozen cod was never interesting to watch.”

Hallberg said that although the implications for the Bolshoi and the Mariinsky were still unfolding, it was “disheartening to think that such great theaters won’t be able to share the beauty they possess, the command of the stage they possess, with the world.”

And yet, most observers said, the Bolshoi and the Mariinsky will weather this moment. Morrison said the Bolshoi had been used for political purposes before, by Russia’s czars and then by the Soviet Union, and its theater had survived being burned down (more than once) and turned into a political convention hall. “It’ll survive longer than these politicians,” he said.

Smirnova agreed. “Regimes change, and the Bolshoi stays,” she said toward the end of an hourlong interview, before giving her husband a quick kiss and heading downstairs to rehearse “Raymonda” with her new partner, Caixeta.

Smirnova and Caixeta rehearsed a short, romantic duet, with Smirnova stopping to finesse its smallest details — a leg extended behind her head, a moment she took Caixeta’s hands — though they had already seemed perfect.

As Larissa Lezhnina, the Russian- and English-speaking ballet master, gave her instructions, Smirnova focused intensely. And then she broke into a broad smile and a little laugh when Lezhnina joked about the position of her posterior in one sequence. In the middle of a ballet studio, for the first time that day, Smirnova looked at home.

This article originally appeared in The New York Times.