By PATRICK KINGSLEY JUNE 29, 2017

DIYARBAKIR, Turkey — Gosto’s kebab shop is not the only diner on its block, let alone on its street. It is, however, the one that perhaps reveals most about the threat to Kurdish culture.

Its owner and manager — the cheery, chubby Vural Tantekin — turned to the kebab trade only in January, after the city authorities sacked most members of his municipally run theater troupe.

“The reason,” said Mr. Tantekin, during an interview squeezed between kebab orders, “was to stop us from performing in Kurdish.”

For people like Mr. Tantekin, the fate of Diyarbakir’s theater troupe is emblematic of an ongoing assault on Kurdish culture at large.

Since the founding of the Turkish republic in 1923, which enshrined a monocultural national identity, the country’s sizable Kurdish minority — around 20 percent of the population — has often been banned from expressing its own culture or, at times, from speaking the Kurdish language.

Turkey’s current leader, Recep Tayyip Erdogan, loosened many of these restrictions toward the end of the last decade, in what some described as a “Kurdish opening.” But repression began again after a cease-fire with Kurdish militants fell apart in 2015. It accelerated further during the crackdown that followed last year’s failed coup.

The crackdown was nominally intended to target the plotters of the putsch. But it has also been used as a smoke screen to squeeze other groups and movements that promote narratives deemed problematic by the government. More than 140,000 people have been fired or suspended from their jobs, and up to 50,000 have been arrested. Among them are those who, like Mr. Tantekin, promote the concept of a unique Kurdish culture.

The suffocation of Kurdish expression in Turkey constituted the latest rollback of reforms Mr. Erdogan put in place during his first decade in power.

Yet the fate of the Kurds has long been one of the central themes in the recent history of the region; one that ignores borders. Kurds in Turkey have been inspired by Kurdish gains in Iraq and Syria, two countries where the Kurds were repressed. Across Turkey’s southeastern border, Kurds run an autonomous zone in northeast Iraq and will hold an independence referendum in September. To Turkey’s south, Syrian Kurds have carved out a territory in northeast Syria and their militias are America’s main partner in the campaign to retake Raqqa, the proclaimed capital of the Islamic State.

And continued successes of those movements will likely further encourage the ambitions of the Turkish Kurds.

Across southeast Turkey, where most people are Kurdish, Mr. Erdogan’s government fired over 80 elected mayors and replaced them with state-appointed trustees. Here in Diyarbakir, the spiritual capital of Turkish Kurdistan, the trustee not only fired most of the city’s municipally employed actors, but also 80 percent of the staff of the municipal department that promoted the teaching of Kurdish and other minority languages.

In towns across the region, trustees have changed the names of streets previously named for prominent Kurdish figures, or removed statues of Kurdish heroes. More than a dozen lawmakers from the main pro-Kurdish party have been arrested in recent months. A Kurdish artist was jailed for doing a painting of the ruins of Nusaybin, one of several Kurdish towns partly destroyed in 2015 during fighting between the Turkish army and Kurdish militants.

Kurdish or pro-Kurdish journalists are some of the principal victims of the post-coup crackdown on free speech. According to the Free Journalist Society, a now-banned, pro-Kurdish news media watchdog, 173 journalists are now in Turkish prisons; of those, 50 worked for Kurdish or pro-Kurdish news outlets.

Turkey’s only Kurdish-language newspaper, Azadiya Welat, was closed last summer — along with at least 10 television channels that broadcast, at least in part, in Kurdish. Even a Kurdish cartoon channel, Zarok TV, was banned for several months before being allowed to reopen in December.

The government says all these closures, bans and arrests are legitimate.

Those fired or now in jail were representatives of or apologists for the P.K.K., the main Kurdish militant group, said Galip Ensarioglu, a lawmaker from Mr. Erdogan’s party who represents Diyarbakir in Parliament. Their dismissal, Mr. Ensarioglu added, does not amount to a crackdown on Kurdish culture, but on the supporters of terrorism.

“There might be some people who were purged because they were considered dangerous — or people who were doing political activities under the name of cultural activities — but never, ever have cultural activities been stopped,” Mr. Ensarioglu said in an interview.

The question of who has the right to speak for Kurdish culture is complex, since Kurds are not a single homogeneous block. Around 30 percent of Diyarbakir’s residents voted with the government in a referendum to grant sweeping powers to Mr. Erdogan’s office. Tens of thousands of Kurds across southeastern Turkey also belong to the Village Guards, a state-sanctioned militia that assists Turkish soldiers in their fight against the P.K.K.

Mr. Erdogan’s Kurdish critics, however, say there is nothing ambiguous about the government’s intentions.

“The aim of the government is very clear,” said Hakki Boltan, the head of the Free Journalist Society, and a former editor in chief of Azadiya Welat. “The policy is to end the Kurdish political movement and the wider Kurdish culture.”

The crackdown on Kurdish culture caught some by surprise, because until recently Mr. Erdogan was widely perceived to have eased restrictions on Kurdish life and language. He also brokered a historic cease-fire with the P.K.K.

Though never enshrining Kurdish as an official language in the Turkish Constitution, he allowed a limited amount of Kurdish-language classes at the high school level and opened a Kurdish-language television channel.

But the situation began to unravel in June 2015, when the peace process broke down, and Mr. Erdogan began once more to tighten restrictions on Kurdish society. Mr. Erdogan’s supporters argue that his hand had been forced: “It was the P.K.K. that said they were done with the peace process,” Mr. Ensarioglu said.

Mr. Erdogan’s critics, however, have another narrative: that by this point Mr. Erdogan was spoiling for a fight. His party had just suffered its worst electoral performance in a decade, hemorrhaging votes to both a new pro-Kurdish alliance and a right-wing nationalist party that opposed his Kurdish overhauls.

Feeling betrayed by Kurdish voters and seeking to win back the nationalists, Mr. Erdogan had already decided to revert to the Turkish state’s traditional stance on Kurdish issues — or so the argument goes.

“Simply to get nationalist support,” said Mehmet Kaya, the head of the Tigris Social Research Center, a think tank based in Diyarbakir, “there began a complete cultural and political attack on the Kurds.”

In Diyarbakir, that perceived policy has involved firing the city’s two co-mayors and canceling plans they promoted to introduce intensive, yearlong, state-funded Kurdish courses for anyone of any age or standard.

The Kurdish name for the city, Amed, was later removed from some city signs, in a move that was repeated in other Kurdish towns. In Van, for instance, about 250 miles away, the state-appointed trustee renamed a park previously named for Tahir Elci, a popular Kurdish lawyer.

In Sur, the ancient district at the center of Diyarbakir, an even more controversial transformation is underway. Contained within a ring of walls first built during the Roman era, Sur was until recently a charming warren of winding streets that many Kurds regarded as the symbolic heart of the Kurdish nation.

But now much of Sur is not only destroyed but also sealed off. Some 2,000 buildings are estimated to have been destroyed or damaged in the fighting and 20,000 residents displaced.

The provincial governor, Huseyin Aksoy, says the area will be rebuilt according to its original character, along the lines of a renovation plan agreed to in 2012 by the mayor, who was pro-Kurdish.

“When’s it’s finished,” Mr. Aksoy said in an interview, “the old atmosphere of Sur will return again.”

Some locals scoff at this.

“They want to Turkify and Islamify the area,” said Abdullah Demirbas, a former mayor of Sur.

Some caution, nevertheless, that the state is not the only obstacle to Kurdish cultural expression. After Abdullah Keskin — the head of Avesta, Turkey’s largest Kurdish-language publisher — criticized Kurdish insurgents for starting a fight in residential districts like Sur, a depot housing his books mysteriously burned down a few days later.

Life was also worse in the past for the Kurdish community, Mr. Keskin says. When he was a child, even Kurdish music was banned. When his family — who lived just north of the Syrian border — held a wedding, they had to enlist Syrian Kurds to perform Kurdish music from the southern side of the border.

Things have not yet reached that level today, Mr. Keskin says. So far this year, his company alone has published more Kurdish books than the entire Kurdish community managed to during the first 60 years of the Turkish republic. But he allows that the government’s actions in the last two years still constitute “a kind of coup against Kurdish language and culture.”

Here and there, however, artists and activists are trying to make the most of a tough situation. Mr. Tantekin, the actor, has left the trade. But several of his former colleagues have set up their own private theater in the basement of a mall.

Their former theater fit 1,700. This tiny basement seats just 80. But it is a start, says Berfin Emektar, one of the players.

“The show,” she said with a smile, “goes on.”