Finalist: The Wall Street Journal Staff

Aydin Akay retired as a renowned defense attorney. He is now in an Ankara prison for downloading a chat app.

By Margaret Coker

Aydin Akay is confined to a prison cell that holds four beds and six men.

In September, Mr. Akay, 66 years old, a judge and internationally known defense attorney, was taken from his three-story island home to Block C of Turkey’s maximum-security Sincan Prison outside Ankara, where he is held as a terror suspect.

The grounds for his arrest show how far the government has gone in its voracious hunt for traitors after the summer’s failed coup: Mr. Akay downloaded a message app available from Google Play and Apple’s App Store.

Turkey’s intelligence service believes he and hundreds of other detainees used the app to hide membership in a secretive Turkish religious group, led by U.S.-based Islamic cleric Fethullah Gulen, which President Recep Tayyip Erdogan blames for the failed overthrow.

About 40,000 people have been arrested. The first wave swept up mostly military personnel and civil servants who allegedly participated in the coup attempt or had ties to Mr. Gulen. Mr. Gulen denies any involvement.

The purges have since expanded to public figures, politicians and activists—in effect, those who have opposed Mr. Erdogan and his ruling party.

Among the criteria cited by the government are Twitter posts or newspaper headlines that allegedly show support for the Gulenists. Turkey has classified the group as a terrorist organization.

Mr. Akay wasn’t a government critic. Instead, he was part of Turkey’s pro-European secular elite. He did not speak publicly about politics. As a lawyer, he worked at various times defending Turkey at the European Court of Human Rights and served as a judge on a United Nations war crimes tribunal.

“How can a society go between such polar opposites this quickly and this much?” Mr. Akay wrote in a prison note viewed by The Wall Street Journal.

More than 3,000 judges, prosecutors and court staff have been dismissed or arrested since summer, crippling work at court houses around the country, Turkish criminal and civil lawyers said.

Turkey’s Constitutional Court, the nation’s highest, has received tens of thousands of appeals from citizens who believe they have been unfairly detained or fired from their work since the failed coup. Two judges on the high court were arrested this summer, accused of being Gulen supporters.

Prosecutors haven’t charged Mr. Akay but have argued for his continued detention as they investigate users of the messaging app, called ByLock.

Turkish intelligence officials have told the Journal that ByLock wasn’t used by the coup plotters, and that by last year the app had fallen out favor among Gulenists. Even so, authorities have compiled a list of more than 180,000 ByLock users as part of the government’s investigation into other alleged plots. Around 9,000 of these alleged users have been detained.

Another Turkish intelligence official said Mr. Akay’s career and lifestyle didn’t match the usual profile of a member of the organization. But the official said Mr. Akay’s extensive use of the app indicated he was a “functional” member of the group. Mr. Akay has denied being a Gulenist.

Mr. Akay’s lawyers couldn’t view his case file, they were told, for reasons of national security. They don’t believe it contains any evidence of wrongdoing—only that Mr. Akay downloaded ByLock.

“There is no proximity between Judge Akay and the coup, or Judge Akay and terrorism,” said Yaman Akdeniz, a Turkish constitutional law expert and one of Mr. Akay’s defense lawyers. “In most countries, there are legal statutes that make possession of certain items a crime unto themselves, like child pornography or hard drugs. But there is nowhere that I know of where possession of an app indicates criminal behavior.”

The Turkish Justice Minister’s office and the prosecutor assigned Mr. Akay’s case declined to comment, citing privacy grounds.

Mr. Akay’s release isn’t expected soon. The loyalty of any judge who frees a detainee in the current political climate would come under immediate suspicion, his lawyers said.

For now, Mr. Akay wakes before dawn to write letters home and fill his diary. To escape the monotony, he walks in the exercise yard, where he can escape in memories of his family and the narrow streets of Istanbul’s historic quarter, of a life abroad, in Paris, in New York and in Africa.

Lawful rise

Strengthening Turkey’s rule of law was a goal drilled into Mr. Akay from an early age, his family and colleagues said. He was raised in Ankara, and his politically active father, also a lawyer, helped build the secular, anti-Communist party now known as the Nationalist Movement Party, or MHP.

Mr. Akay avoided politics, and after passing the bar went into private practice in the capital. In 1985, he met his future wife, then a graphic designer, at a dinner party hosted by mutual friends.

Over cigarettes and glasses of Turkey’s anise-flavored alcohol raki, they discussed politics and philosophy. Alahan Akay said her future husband wasn’t put off because she was a single working mother with a young son: “He had a progressive and open mind.”

On weekends, Mr. Akay, who lived in Ankara, began visiting his future wife, who lived in Istanbul, a five-hour drive each way.

Once married, Mr. Akay followed his wife’s advice and joined the Turkish foreign service, where her brother worked. The couple, who later had a daughter, sought adventure in a cosmopolitan life abroad.

In 1989, they moved to New York City, where Mr. Akay worked as the legal attaché for Turkey’s mission at the United Nations in Manhattan. The family lived nearby, on 2nd Avenue and 43rd Street, and the children attended local Catholic schools. The family toured the U.S. by car on vacations, Mrs. Akay said. They tried new cuisine, like crabs from the Chesapeake Bay in Baltimore. Their son became a long-suffering fan of the New York Jets.

In the mid-1990s, Mr. Akay was posted to Strasbourg, France, where he defended Turkey at proceedings at the European Court of Human Rights. Turkish citizens, mostly Kurds, alleged they were tortured and abused by the security forces during some of the bloodiest years of insurgency by the outlawed Kurdistan Workers’ Party.

Mr. Akay also participated in debates at the Council of Europe, the body that oversees international human-rights conventions, which the newly independent Eastern European states were eager to join. Jon Ivanovich, the Macedonian ambassador there at the time, said he and Mr. Akay became friends after hours spent talking about the transition from authoritarian societies to nations where civil liberties were enshrined.

“He was proud of his nation and was a real believer in Turkey’s rightful place in Europe,” Mr. Ivanovich said.

By the early 2000s, after another tour in Strasbourg, the Foreign Ministry nominated him as a judge for a tribunal set up by the United Nations Security Council to adjudicate alleged war crimes during the Rwanda genocide. In 2009, he moved to Arusha, Tanzania, and ruled over five cases there.

Mr. Akay took a break from his legal career and accepted a two-year post, starting in 2012, as Turkey’s first ambassador to Burkina Faso. He was motivated by retirement worries after a life in civil service: An ambassadorship would significantly increase his government pension, his family said.

A senior official in Turkey’s National Intelligence Agency, known by its Turkish initials MIT, said the spy agency is now examining whether Mr. Akay was directed by Gulenists to take the post in Burkina Faso, or whether he used his position to further Gulenist ambitions.

MIT believes supporters of Mr. Gulen worked for years to illegally influence state policy, including the expansion of Turkish embassies across Africa to boost their commercial enterprises. Mr. Akay represented Turkish business interests impartially while serving as ambassador, his lawyer said.

Mr. Gulen’s followers number in the millions, and businessmen affiliated with the cleric include those at some of Turkey’s largest companies. Affiliation with Mr. Gulen or his followers’ businesses wasn’t illegal and Messrs Gulen and Erdogan for many years had been political allies. In May, Turkey’s National Security Council labeled the Gulenists an armed terrorist network. And after July’s coup, such relationships exposed many in Turkey to arrest with little or no warning.

Taken away

Mr. Akay returned to Turkey in 2014 and retired from the foreign service around his 65th birthday. In 2015, he took up his judicial duties at the appellate tribunal based at The Hague and formed by the U.N. to hear cases related to Rwanda and former Yugoslavia war crimes tribunals.

Over the summer, Mr. Akay was deliberating a motion filed by convicted war criminal Radovan Karadic when rogue elements of the Turkish military tried to overthrow the government. He and his wife were at home on the island of Buyukada, known as the Martha’s Vineyard of Istanbul.

At least 270 people died during the coup. Jet fighters bombed parliament in Ankara and tanks fired on civilians in Istanbul. Days later, the government called a state of emergency. Officials said they needed extraordinary powers to combat traitorous citizens, as well as Islamic State and the Kurdistan Workers’ Party—two groups that have killed about 300 people in suicide attacks so far this year.

The couple struggled to make sense of the violence. Mr. Akay became disenchanted with some of his friends in his secular social set who had rooted for Mr. Erdogan’s downfall, his family said. In conversations over drinks, Mr. Akay was clear: Military rule was never a better alternative to a democratically elected government.

For the rest of the summer, life for the Akays was relaxed. The couple baby-sat grandchildren and swam at their beach club. In September, they flew to Israel with Jewish friends and visited Jerusalem for the first time.

Three days after their return, on Sept. 19, Mrs. Akay was cooking pasta for lunch when the doorbell rang. A dozen or so police entered the house, handcuffed Mr. Akay and declared him a national-security threat.

Police confiscated electronic devices and picked through the 2,000 or so books in Mr. Akay’s home library, which was filled with legal case studies, Paris guide books and histories of Western philosophy. They confiscated two nonfiction books, including one about Mr. Gulen.

Police moved Mr. Akay to Sincan, where suspected senior coup plotters are held. For five days, counterterror police questioned his use of ByLock and his professional associations abroad, according to his lawyers and a copy of the prosecutor’s statement viewed by the Journal. Mr. Akay told them he had downloaded the app and used it in 2015, along with other chat apps such as WhatsApp. He said he used it to communicate with friends in Burkina Faso about personal matters.

Mr. Akay denied to authorities any association with Mr. Gulen or the coup, calling it absurd to suspect him of membership in a religious organization trying to subvert democracy.

“It is evident from my social, cultural and family life that I can’t be thought of in the same sentence as” the Gulenist terror group, he said, according to a copy of the prosecutor’s report viewed by the Journal.

During a Sept. 28 court appearance, Mr. Akay’s legal team argued for his release for lack of evidence. They later said the arrest violated the diplomatic immunity granted Mr. Akay as a U.N. official. The judge denied his release.

Turkey has told the U.N. Mr. Akay stands accused of “very serious” crimes and that any immunity would apply solely to his duties as a tribunal judge, a Foreign Ministry official said.

“We keep hoping every day there is going to be a change, that we will wake up and the country will go back to normal,” said Mrs. Akay, who now lives with her son and his family in Istanbul. “But the reality is that my husband is caught in a spider’s web. For now, there is no escape.”

In Sincan, Mr. Akay shares a cell with five men, who like him, had been among Turkey’s elite: judges, military officers and academics. Sharing two beds and two mattresses on the floor means the six men sleep poorly, sometimes in shifts.

Most of his cell mates wake before dawn for morning prayers. Mr. Akay uses those rare moments of solitude to write letters home. They are read by a prison censor, so Mr. Akay writes as blandly as the prison stew. One described how prisoners sometimes share snacks bought at the prison store.

Mr. Akay’s morning walks in the prison yard help relieve his worries—about his wife, who survived a bout of breast cancer—and offer reminders of happier times such as the safari the family took to the Ngorongoro Crater in Tanzania, according to letters viewed by the Journal.

He rarely watches the TV that serves his cell block, he wrote: The scenes of Istanbul trigger a painful homesickness. He is allowed family visits but has asked his wife and daughter to stay away. He is afraid seeing them would crumble the stoicism that shields him day to day.

Only his son, Kerem, also an attorney, visits the prison outside Ankara. The weekly journey reverses the route Mr. Akay would take while courting Mrs. Akay. It is now a trip often filled with dread, the son said, for “the uncertainty over whether it will be my last chance to see him.”

At the end of October, Mr. Akay’s lawyers lost an appeal for his release on bail. They have filed an appeal to the Turkish Constitutional Court. Their next move is to take Mr. Akay’s case to the European Court of Human Rights, where the lawyer had once defended Turkey.

His family struggles to keep faith in the legal system that Mr. Akay spent a career championing. Mrs. Akay hasn’t returned to the island home where she and her husband had hoped to grow old together. The table is still set in blue china plates for a lunch never shared.

Country’s president, strongly supported by conservatives, Islamists and nationalists, is accumulating authority, purging thousands accused of involvement in a failed July coup, and ruling by decree

By Emre Peker and Joe Parkinson

SIVAS, Turkey—Kemal Akinci’s reverence for Turkey’s president runs so deep that when his wife gave birth to triplets he named them after the leader: Recep, Tayyip and Erdogan.

When news of a coup attempt broke in mid-July, the 33-year-old baker asked his wife to pray for him and rushed to the streets in protest, beginning 27 straight days of demonstrations in the medieval square in support of his hero. “I’m ready to give my life for the president, and that was the spirit of the crowd, too,” he said.

In the months since the failed coup, devotion such as his has moved from the fringe to the political mainstream, fortifying an Erdogan personality cult that is now reshaping Turkey’s democracy.

Across the country, Mr. Erdogan’s image has become omnipresent, gazing from billboards, TV screens and newspapers. A biopic called “The Chief,” his nickname, is due for release around his birthday in late February. A song titled the “Erdogan March” lauds what it calls the lion-hearted protector of the global Muslim community, and became a Twitter top trend in Turkey. When the president asked Turks to exchange their dollar savings for Turkish lira to stop the currency’s slide, thousands complied, fuelling a brief rally.

Bolstering the genuine public support, which pushed Mr. Erdogan’s approval rating to 68% after he put down the rebellion, is a fast-expanding architecture of power that many here regard as repression.

Since July, more than 125,000 mostly public employees have been purged, including 40,000 who are under detention. The government of Mr. Erdogan has closed more than 169 media outlets during the same period. It has jailed the entire top leadership of a pro-Kurdish political party that won six million votes in an election last year.

Mr. Erdogan delivers daily hourlong speeches, which television stations that haven’t been shut down uniformly broadcast live.

With the opposition cowed or co-opted, Mr. Erdogan appears almost sure to achieve his longstanding ambition of overhauling Turkey’s constitution by establishing an executive presidency. Under Mr. Erdogan, his behavior over the past few years suggests, that would essentially mean one-man rule.

“I don’t care if they call me a dictator or whatever else. It goes in one ear, out the other,” Mr. Erdogan said at an Istanbul university on Oct. 6 as he accepted the latest of some three dozen honorary doctorates. “I have come to serve my people, not dominate over them.” The president’s office didn’t respond to a request for comment for this article.

Turkey is going through its most tumultuous time in decades. The murder of Russia’s ambassador to Turkey on Dec. 19 capped 10 days of violence, including bombings that killed at least 58 people—volatility that only strengthens Mr. Erdogan’s push for expanded powers.

His unfolding efforts to reshape Turkey place Mr. Erdogan in the vanguard of illiberal populism personified by leaders such as Russia’s Vladimir Putin, Hungary’s Viktor Orban, the Philippines’ Rodrigo Duterte and Venezuela’s Nicolas Maduro. Mr. Erdogan’s movement has been a long campaign against a secular elite installed early last century by Turkish independence hero Mustafa Kemal Ataturk and kept in power by the military.

His movement, sometimes called Erdoganismo, is an Islamist-infused cocktail of winner-take-all democracy, nationalism and nostalgia for the past glories of this onetime center of the Ottoman Empire. Those sidelined include the once-dominant secular and West-leaning intelligentsia, along with ethnic and religious minorities.

The secret to the power grab is a political base of religious Sunni Muslims who have seen their incomes rise, their formerly circumscribed rights restored, and their pride enhanced by Mr. Erdogan’s policies. Zealous support from this bloc, about half of Turkey’s voters, has helped ward off challenges from critics and political opponents.

“The more they tried to stop Erdogan, the stronger he got. Without realizing, they created a giant,” said Murat Toraman, a software entrepreneur in Sivas and councilor with the ruling Justice and Development Party, or AKP.

Supporters say Mr. Erdogan, who has marshaled nine AKP election victories since 2002, has shown himself a benevolent and capable leader. Dismissing the idea he is autocratic, they credit his skill at developing trust and credibility across society.

The steep accumulation of Mr. Erdogan’s power since the failed coup, as he rules by emergency decree, has spooked fellow members of the North Atlantic Treaty Organization.

“His leadership is moving into a new phase. The narrative is transparent—Erdogan is on a constant march toward absolute power,” said Marc Pierini, a former European Union ambassador to Turkey who’s now at the Carnegie Endowment for International Peace in Brussels.

Mr. Erdogan has used decrees to overhaul institutions from the military command to university leadership. When a bill to replace elected municipal leaders with trustees failed in parliament, Mr. Erdogan imposed it with a decree. Then his government ousted scores of pro-Kurdish mayors on terrorism charges.

Liberals and technocrats who formed part of the AKP’s oncebroad coalition have been slowly expunged, some fleeing into exile. Party co-founders have been sidelined or silenced, their names erased from AKP literature.

“This practice is very dangerous. This is paving the way for authoritarianism under one-man rule,” said Utku Cakirozer, a lawmaker with the main-opposition Republican People’s Party.

Mr. Erdogan’s predecessor as president, AKP co-founder Abdullah Gul, said the situation risks Turkey’s institutions. “Elections are without a doubt the foundation of democracy, but if you leave it at that it would lead to a majoritarian understanding and that’s not true democracy,” Mr. Gul said. “One of Turkey’s biggest issues is checks-and-balances; the political parties aren’t powerful enough to challenge each other, and individuals can make mistakes.”

Observers from Sivas to Washington say Mr. Erdogan has accumulated power through deft pivots: spotlighting an Islamist agenda in certain situations, and downplaying Islam in others.

His party swept to power in 2002 after courting European and U.S. policy makers enamored by the thought of an Islamist democratic party in the mold of Christian Democrats like Germany’s.

Many Turks who favored Islamic-rooted government initially didn’t support him. Mr. Toraman in Sivas didn’t trust the AKP’s Western-oriented agenda. Although Mr. Erdogan sought to expand rights for observant Muslims held back by secular rule, he did so within a campaign to persuade Europe Turkey belonged in the EU.

Threats by the military to quash his program won Mr. Toraman to his side. Mr. Toraman, now 32, joined AKP youth ranks and rose to elected local office.

After antigovernment protests broke out in 2013, starting with environmentalist opposition to commercial development of an Istanbul park, Mr. Erdogan embraced more overtly Islamist and nationalist policies. He framed protesters as elitists or foreign agents. He began accusing onetime ally Fethullah Gulen, a cleric living in the U.S., of inspiring opposition to him, which Mr. Gulen denies.

Since July, the failed coup has provided cover for Mr. Erdogan to complete his political project. He should be handed as much power as he needs, Mr. Toraman in Sivas said, because “he’s restoring Turkey’s historic greatness.”

Cities such as Sivas, at the crossroads of Anatolia’s economically thriving center and depressed east, form the bedrock of Mr. Erdogan’s power. Heartland supporters say outsiders can’t imagine how dramatically Mr. Erdogan’s rule has improved life for Turks once limited by an immutable class system. Seeking treatment for illness was a challenge. Families couldn’t afford to send children to school. Conservative men tell of being ousted from the staunchly secularist military because of their piety.

Mr. Erdogan’s successful challenge to that system is a motivational story for millions. Merve Subutay, an officer of the AKP’s women’s wing in Sivas, cites Mr. Erdogan’s life story—a ferry skipper’s son who rose to big-city mayor and president— as a model for her own big ambitions.

When she was young, her father’s recounting of Turkish legends made her dream of joining the army. As an adolescent she saw the futility of that, after her religion deepened and she donned the Islamic headscarf.

Studying biology at her hometown’s Cumhuriyet University, she faced a dilemma. The school, like all public institutions, barred outward signs of religion. To continue, she had to remove her hair covering daily on entering the campus.

In her junior year, Mr. Erdogan’s party revoked the headscarf law, and her future widened. Now, as she finishes a master’s degree in optical engineering, Ms. Subutay is angling for a coveted job with a defense contractor, Aselsan, which has opened an optics factory in Sivas. Until recently, it would have been impossible for a headscarfed woman.

“You might not always agree with” Mr. Erdogan, Ms. Subutay said, “but when all is said and done, you see that he was right.”

Mr. Erdogan’s appeal also owes in part to a Teflon ability to deflect bad press.

The president’s lifestyle has moved beyond comfortable to opulent. He lives in an 1,100-room palace with 1,800 employees. It is part of a prime minister’s complex built while he held that post, but was inaugurated as the presidential palace after Mr. Erdogan won the presidency in 2014.

None of this dents a cultivated down-home image, which Mr. Erdogan burnishes in televised meetings with local officials called mukhtars.

Ahmet Dagasan, from the Gultepe neighborhood in Sivas, attended a gathering last year. Mr. Erdogan discussed topics from Syria to Kurdish insurgents. At lunchtime, he asked the TV crew to leave the room. Then he rolled up his sleeves, ignored the silverware and grabbed a lamb chop, telling those present to make themselves at home.

“My mukhtars, be comfortable, eat as I eat,” Mr. Dagasan recalls the president saying.

While some call such moves a crass attempt to politicize an office that had long been nonpartisan, to Mr. Dagasan they show “he treasures us, because he comes from among us.”

Although Mr. Erdogan is wildly popular in the Sunni majority, many secularists and members of minorities see him as a dictator who fuels a dangerous polarization.

In 2002 when his party gained power, many Kurds, liberals and Alevis—members of a Shia offshoot of Islam—were hopeful the AKP would bring a more inclusive political culture. That hope died, said Ali Dag, an Alevi leader, when Mr. Erdogan started invoking the phrase “national will” to defend his policies, which primarily cater to his Islamist supporters. Mr. Erdogan has ignored pleas from minorities in favor of rhetoric that galvanizes nationalist feeling and the Sunni majority.

The president dismisses such allegations, pointing to initiatives such as returning state-seized properties to religious minorities. He has said he embraces everyone who upholds four principles: one nation, one flag, one homeland and one state.

Kurds, who are 20% of the population, are the latest to find their fate intertwined with Mr. Erdogan’s ambitions.

A three-decade insurgency by the Kurdish group PKK, which Turkey and its NATO allies list as terrorist, finally led to peace talks with the government in 2013. They were mediated by the legal pro-Kurdish Peoples’ Democratic Party, or HDP.

In last year’s elections, however, the HDP doubled its previous showing and won 13%. That was enough to deny Mr. Erdogan’s party a ruling majority in parliament.

Mr. Erdogan then accused the HDP of supporting terrorism. He revived scorched-earth tactics against Kurdish insurgents. He froze the peace talks and called snap elections. With voters spooked by rising violence and insecurity, the AKP was propelled back to majority control of parliament.

“Erdogan really is dragging Turkey toward Third-World standards, a total dictatorial structure and culture of obedience whereby he crushes anyone who is not subservient,” an HDP member of parliament, Garo Paylan, said in an interview. Three days after he spoke, police arrested his party’s entire top leadership in midnight raids. Most remain in jail, facing terrorism-related charges.

Mr. Akinci, the man who patrolled Sivas’s main square for weeks after the July coup attempt, says he would do whatever it takes to help Mr. Erdogan. He and his wife, Dicle, credit Mr. Erdogan’s improvements to the health system with literally bringing their children into the world.

The introduction of mandatory workplace health insurance helped pay for Mrs. Akinci’s medical bills during a difficult first pregnancy. Then, after the birth of their daughter, it paid for treatment necessary for her to conceive again.

When the Akincis learned they were expecting, this time triplets, there was no doubt what the babies’ names would be.

“It’s important for Tayyip Erdogan to stand tall for our nation. The more swagger he has the prouder we are,” said Mr. Akinci.

Gesturing to his triplets, he added: “God willing, they will get to great places like their namesake.”

Crackdown, which has snagged associates of imam Fethullah Gulen and others, is designed to remake country’s higher education in president’s image

By Joe Parkinson and Emre Parker

KONYA, Turkey—On the humid afternoon after July’s bloody coup attempt, signs of a rift that is redefining this nation’s academia played out in two cities 400 miles apart.

In Istanbul, Nil Mutluer grabbed her 3-year-old daughter and raced with a suitcase toward Turkey’s coast. The former sociology-department chair at the city’s Nisantasi University narrowly escaped the nation’s looming dragnet.

“Authorities had already begun questioning colleagues at the airports,” said Dr. Mutluer, 42, a Western-leaning liberal who took a ferry to Greece en route to an academic post in Berlin.

That afternoon in Konya, once known as the Citadel of Islam, some local professors cheered the coup’s failure as a chance to remake Turkish academia. “Elitist professors are looking at the world with Western glasses—they’re not really thinking about what the Turkish people want and need,” said Assistant Professor Sedat Gumus, 33, a U.S.-educated lecturer at Konya’s Necmettin Erbakan University, named after President Recep Tayyip Erdogan’s political mentor.

“The current situation might be a golden opportunity for Turkey to write a new constitution,” he said, “and with it reform the higher-education system.”

Turkey’s crackdown after the July 15 putsch has been swift and expansive, sweeping through the military, judiciary and higher education. The government declared a state of emergency and said it has detained more than 40,000 people as it hunts for suspected affiliates of the man officials accuse as the mastermind, Fethullah Gulen, a U.S.-based Turkish imam. Mr. Gulen, who counts millions of supporters in part because of his network’s investments in education, has denied any role.

Overnight, educators became a suspected class. The Education Ministry dismissed more than 27,000 staff and Turkey’s Council of Higher Education forced all 1,577 university deans to resign, saying only those with no ties to coup plotters would be reinstated. The university watchdog also ordered each university to list faculty suspected of links to Mr. Gulen and has suspended 4,225 academics. The 15 Gulen-linked universities have been sealed like crime scenes.

So far, the purge has affected mainly academics on the outs with Mr. Erdogan even before the coup attempt, chiefly those connected to Mr. Gulen and to causes seen as critical of the government. But the chill is broadening, and many academics from top schools, expecting a second wave of purges, are seeking work abroad.

The convulsions in Turkish academia reflect the latest and perhaps most transformative chapter in the long-running story of Turkey’s split between its urban elite and conservative-Muslim interior, showing the acceleration of the country’s shift from stalwart Western ally to aspiring regional power.

The gathering intellectual purge is arming allies of Mr. Erdogan to realize a goal of their own: to tip the balance of power away from the Western-oriented ivory towers in Istanbul and Ankara toward what ruling-party adherents call academies for “New Turkey”—an amalgamation of Islamic piety and nationalism rooted in the Ottoman past.

The government has suspended the U.S. State Department’s Fulbright English Teaching Assistant program and canceled the European Union’s Jean Monnet scholarships after the failed coup.

Batuhan Aydagul, director of the Education Reform Initiative at Istanbul’s Sabanci University, said the shift could rob an institutional anchor that has linked Turkey with its Western allies and erode Turkey’s position as an emerging globalized economy.

A senior Turkish government official dismissed concerns that Mr. Erdogan’s vision conflicted with Turkey’s interests, saying: “Turkey has excellent schools and departments. Obviously we would like to have the best departments on all subjects.” The Higher Education Council didn’t respond to requests for comment. Ruling-party leaders have said the post-putsch crackdown has support across Turkish society.

Academics affected by the purge include some of the more than 1,000 who signed an open letter in January calling for peace talks between the government and Kurdistan Workers’ Party, or PKK, a designated terrorist group that wants autonomy in majority-Kurdish southeast Turkey.

Maya Arakon, 44, a self-described secularist and liberal, faced a dual threat after the failed coup. She signed the letter and was an associate professor at Istanbul’s Suleyman Sah University, established by Gulen followers in 2010, which the government closed after the putsch.

“I was in shock,” said Ms. Arakon, whose Istanbul apartment was covered in boxes as she prepared to leave for the U.S. “I feel unwanted and disliked, that my life, thoughts, existence are under threat.”

Candan Badem, 46, a history professor in the eastern city of Tunceli and a signatory to the letter, was suspended in early August, which Tunceli University officials said was related to the crackdown against Gulen followers. His lawyer discovered he was being investigated as a suspected coup plotter because authorities found at his university office a book by Mr. Gulen.

“The investigation is a total joke,” Dr. Badem said, citing his yearslong criticism of the imam. Tunceli University didn’t respond to inquiries.

Fear has spread across academia, with many Turkish intellectuals saying they are afraid to speak out and that their cellphones are tapped and research restricted.

Universities in Sweden, Germany and Austria have reported a surge in inquiries from Turkish academics. Karabekir Akkoyunlu, an assistant professor specializing in modern Turkey at Austria’s University of Graz said colleagues back home had inquired about positions over the past month for the first time.

“All of a sudden we are inundated with requests from junior and senior academics,” said Umut Ozkirimli, a Turkish political scientist at Sweden’s University of Lund, who said dozens of Turkish academics have called him looking for work in Europe or the U.S. “Now there is a sense of urgency as people are desperate.”

Some conservative academics argue professors have never been freer to pursue previously taboo subjects such as Kurdish separatism and Islamic politics. “I’m very certain there’s no systematic pressure on academic studies,” said Necmettin Erbakan University’s Prof. Gumus. “People shouldn’t mix the reaction to political statements and academic freedom.”

A Secularist past

For decades, top universities including Istanbul’s Bogazici and Ankara’s Middle East Technical played an outsize role in shaping a secular-minded national culture in line with principles laid out by the republic’s founder, Mustafa Kemal Atatürk. Secularist elites controlled professorial appointments and vetoed research in areas considered detrimental to the government’s pro-Western orientation. Head scarves were banned from campuses, a rule that kept generations of women out of higher education.

When Mr. Erdogan’s Justice and Development Party, or AKP, swept to power in 2002, ending that ban was among its priorities. Animosity from the secular elite meant it took almost eight years to repeal.

Mr. Erdogan has defined his philosophy of education as building “a religious generation.” In a May speech accepting an honorary doctorate at Turkey’s Kocaeli University, he trumpeted his government’s success in expanding education opportunities for students from all backgrounds, including his conservative religious constituents.

Under AKP rule, university enrollment more than tripled to 6.7 million and the government has opened 57 new public universities, many in areas historically lacking educational and political opportunity. Universities run by private foundations, including Gulen affiliates, jumped to 68 in number from 20.

The new universities have been a source of pride for provincial academics and communities. Recep Tayyip Erdogan University in Rize, the president’s hometown, has benefited from government largess and is among Turkey’s fastest-growing universities. In the decade since the school was founded—it was renamed after Mr. Erdogan in 2012—its number of academics has risen almost 10-fold to 1,000 and the student body has tripled to 18,000.

The institution has had a positive impact on the region, said Taner Erol, 36, a communications lecturer and Erdogan University’s spokesman. It has helped establish and staff outpatient clinics in the region, he said, and its researchers are studying fish diseases in the Black Sea and are working on regional disaster-prevention plans. Students from Europe and the U.S. have for decades almost exclusively attended elite colleges of Istanbul and Ankara. Erdogan University has admitted hundreds of international students, burnishing Turkey’s standing in the world, Mr. Erol said.

‘Ideological nepotism’

State funding has been funneled toward the new public universities and faculties that specialize in subjects dear to the ruling party’s interests, such as Ottoman history and Islamic studies, education watchdogs and opposition lawmakers say.

Ahmet Acar, 67, whose eight-year tenure as president of Ankara’s Middle East Technical University ended this summer—not purge related—said he agreed with the capacity-building policy but felt the pace has hurt education quality. “Once you recruit and promote people on anything other than academic or professional qualifications, such as on the premise of political views and associations, then you can forget about the future of these universities.”

Some former members of Turkey’s Scientific and Technological Research Council say the institution even before the putsch had been filled with loyalists who channeled funding toward religious-minded scholarship. The Research Council didn’t respond to inquiries.

“This is about ideological nepotism,” said Ali Alpar, a 65-year-old astrophysicist at Istanbul’s elite Sabanci University who was once a Research Council board member. “As they purged the old ranks, the clear criteria was that new people would be close to the government, be trustworthy—by which they meant they would belong to religious congregations.”

Last week, the ruling party proposed a law to abolish rector elections and allow Mr. Erdogan to pick each academy’s chief from a list provided by the Higher Education Council. The government pulled the bill after a rare show of unity from opposition parties.

In recent years, some academics say, it has been harder to find research funding or jobs in a field once wide open to Western-minded academics such as Dr. Mutluer. She gained her Ph.D. in Budapest before returning to Istanbul to lecture in several sociology faculties. She was promoted to head that department at private Nisantasi University, not associated with Mr. Gulen. She produced a political-analysis television program, Oteberi, or “Paraphernalia,” broadcast on a channel known for championing views critical to the government.

Some universities operated by Gulen-linked foundations became a haven for critical thinkers when other private academies shunned them to avoid angering the government and state universities prioritized the hiring of professors with other ideological stripes.

Earlier this year, the tension between academics erupted over one of Turkey’s most sensitive subjects, its war against the PKK, which Turkey and the North Atlantic Treaty Organization designate a terrorist group. Dr. Mutluer signed the January letter calling for peace talks, which described the government’s counterterrorism operations as a “massacre.” Mr. Erdogan called the statement “treason by so-called intellectuals.” Turkey’s Higher Education Council vowed to act against signatories.

Dr. Mutluer said she received death threats from nationalists. By February, she said, she was fired by Nisantasi University, which didn’t respond to inquiries from The Wall Street Journal. After the putsch, hearing that authorities were about to ban travel by academics, she left Turkey for a fellowship she had lined up teaching at a program for scholars at risk at Berlin’s Humboldt University.

“It wasn’t an easy decision to leave, but I couldn’t stay in Turkey—we could no longer speak,” she said. “The civil space has been shrinking…now there’s very little civil space at all.”

On the other side of the rift are dozens of up-and-coming academics such as Prof. Gumus who are optimistic about their careers. He graduated from one of the country’s oldest institutions, Atatürk University in his hometown of Erzurum, with a degree in mathematics pedagogy. He taught in public schools before getting a doctorate at Michigan State University.

Prof. Gumus contested the view that only pro-government ideologues have a chance to advance. He said everyone in Turkey is benefiting from broadening education opportunities under Mr. Erdogan.

“No government sufficiently responded to public demands until the AK Party,” he said. “I see it as a democratization of education.”

Juggling terror threats from Islamic State and Kurdish separatists, Turkey’s vast intelligence service struggled to make sense of clues before plotters sprung to action on July 15

By Joe Parkinson and Adam Entous

ANKARA—In the months before Turkey’s failed coup, the country’s spy agency penetrated online chat rooms and decoded millions of secret messages but found no mention of the plot, senior Turkish intelligence officials said.

Agents checked tips pointing to a coup that led nowhere. Analysts studied the video sermons of an imam who the government alleges directed the plot and speculated if the color of his robes relayed secret orders to his followers.

Turkey’s spies, juggling terrorist threats from Islamic State and Kurdish separatists, struggled to make sense of clues that never seemed to add up until the conspiracy they feared most materialized on the night of July 15.

Failure to detect the coup revealed the limitations of Turkey’s spy agency, known as MIT, which is widely seen as operating a far-reaching domestic surveillance system that government critics allege serves to protect President Recep Tayyip Erdogan.

The challenge of sifting through a daily avalanche of electronic communications was compounded by encryption apps used by the alleged plotters, leaving Turkey’s spy service in the dark this year for several months.

U.S. intelligence agencies, whose work with the MIT is colored by distrust, also didn’t see the coup coming, officials said, even though it threatened to compromise the North Atlantic Treaty Organization’s second-largest army. The agencies saw only brewing political resentment, with U.S. surveillance of communications in Turkey focused on militants, not military officers.

Turkish authorities have singled out Pennsylvania-based religious leader Fethullah Gulen as the coup’s mastermind and launched a purge against tens of thousands of his alleged accomplices. They have demanded the U.S. grant extradition of Mr. Gulen to Turkey, adding to tension between the two nations.

Mr. Gulen and his organization Hizmet deny any role in the coup and have alleged Mr. Erdogan orchestrated it himself to build a dictatorship, a claim the president has denied.

Alp Aslandogan, who speaks on behalf of the imam, said claims that Mr. Gulen was involved were wrong, and if Mr. Gulen’s sympathizers participated in the coup, they did so without the cleric’s sanctions. The imam has repeatedly sought to distance himself from the coup, whose participants, he wrote in a newspaper op-ed this week, have “betrayed my ideals.”

American officials say they suspect followers of Mr. Gulen participated, but the U.S. doesn’t have access to primary sources in Turkey to determine independently who did what in the coup attempt. So far, they said, there is no credible evidence of Mr. Gulen’s personal involvement.

Some of Turkey’s Western allies have expressed concern that Mr. Erdogan is using the coup to widen the purge well beyond the alleged participants.

This account of the July 15 coup attempt that left 246 people dead in Istanbul and Ankara was based on interviews with senior Turkish intelligence officials, U.S. and other Western diplomats, and followers of Mr. Gulen.

Broken alliance

Long before Turkey’s spy agency turned its sights on Mr. Gulen, he and Mr. Erdogan were partners. The men had different Islamist philosophies but worked together, beginning in the late 1990s, to capture power from Turkey’s secular establishment.

To bolster Mr. Erdogan’s government and his own influence, Mr. Gulen asked his followers to seek leading roles in the bureaucracy.

At the peak of the partnership in 2010, the imam’s followers in the police, judiciary and media, helped jail hundreds of top military officers they accused of plotting a coup to remove the Islamist government.

The convictions were quashed years later, after revelations the evidence was fabricated. But it paved the way for Mr. Gulen’s sympathizers to rise to positions of power in the military, Turkish and U.S. officials said.

In 2012, the alliance between Mr. Erdogan and Mr. Gulen collapsed over disagreements about power sharing, sparking a feud that put the imam’s supporters under the scrutiny of MIT chief Hakan Fidan.

Inside Turkey’s spy agency, a group of senior analysts have since spent their days picking through intelligence on Mr. Gulen’s followers and analyzing the imam’s sermons—both words and gestures—for alleged hidden messages.

Mr. Gulen and his group had long frustrated the spy agency: Aware of MIT’s snooping, they imposed strict discipline over their communications, helped by military intelligence veterans fluent in the spy game.

Mr. Aslandogan, who speaks on behalf of Mr. Gulen, said the movement “has a problem with transparency” because of longterm persecution by the Turkish state.

The religious leader stopped using telephones and gave instructions in person to a handful of top advisers during visits to Mr. Gulen’s home in Pennsylvania. Ankara asked Washington to bar Mr. Gulen’s followers from entry into the U.S., but administration officials didn’t believe they posed a threat.

To avoid detection, the group in 2014 started using ByLock, an encrypted messaging app, according to senior Turkish intelligence officials.

“I have no direct knowledge of such a practice. If true, it might be that they are trying to avoid the wrath of the government,” said one person close to the movement.

The MIT discovered the communications channel last winter and began the laborious process of decrypting the messages, which numbered in the millions. The agency eventually identified 40,000 names, including 600 senior military officers, suspected of connections with the group.

None of the ByLock messages referred to a coup plot, senior Turkish intelligence officials said.

U.S. intelligence agencies knew of growing political opposition against Mr. Erdogan. A classified U.S. assessment included Turkey on a list of countries at heightened risk of political instability, but it didn’t predict a coup.

At the time, U.S. intelligence-gathering about Turkey focused on Islamic State and other terror threats, not the Turkish military.

Soon after the MIT gained access to the ByLock messages, operatives of Mr. Gulen’s organization realized the channel had been compromised and switched to a different messaging app that remained impenetrable, senior Turkish intelligence officials said. In early spring, the Turkish spy agency shared the decrypted files with other government ministries. Turkish intelligence officials said that tipped off Mr. Gulen’s group that the messages had been decoded.

Days later, on March 21, Turkish analysts saw a YouTube video that showed Mr. Gulen wearing for the first time a khaki robe the same green hue used by the army.

Analysts at MIT believed he was signaling his followers in the army, but they had no idea what. A person close to the Gulen group said such speculation was unfounded.

Plot revealed

Four days before the coup, the Turkish spy agency forwarded the names of the 600 military officers under suspicion to the military’s general staff. The plan was to sideline them during the annual meeting of military leaders in August.

Turkish and U.S. officials believe that warned the plotters their time was growing short.

In the late afternoon of July 15, analysts at Turkey’s spy agency got a tip of unusual troop movements at a Ankara’s airborne academy, as well as the Akinci Air Base 30 miles northwest of the capital.

Senior officers at the intelligence agency prepared a brief report and sent it by fax to the military’s general staff headquarters. Around 5:30 p.m., a senior intelligence official, Mr. Fidan’s deputy, went to the headquarters to share firsthand the agency’s suspicions about the troop movements.

A senior commander visited the academy and found that the attack helicopters had been armed with missiles. He was told it was for a military exercise. Suspicions lingered.

At 6 p.m., Mr. Fidan went to army headquarters, and Gen. Hulusi Akar, Turkey’s top soldier, agreed to visit the Akinci Air Base himself.

Mr. Fidan returned to MIT headquarters and waited to notify Mr. Erdogan, who was on vacation on Turkey’s Mediterranean coast.

Mr. Akar never reported back. He was taken hostage. Mr. Akar later said that a brigadier general who was part of the plot had urged him to speak with Mr. Gulen, and he had refused.

By 9 p.m., it was clear something dramatic was afoot. About an hour later, coup forces reached the MIT headquarters of Turkey’s spy agency.

Two Super Cobra attack helicopters and three Sikorsky troop movers carrying commandos raked the compound with cannon fire. Mr. Fidan was kept outdoors for fear jets would bomb the buildings. He and his staff, protected by armed security teams, took cover among trees.

When a Sikorsky descended to drop off commandos, agency bureaucrats, including those with little or no weapons training, fired handguns. Sparks flew from rounds ricocheting off the helicopter’s fuselage. “Fight until the last bullet, they shouldn’t capture you alive,” Mr. Fidan told his aides.

Between 1:30 a.m. and 2 a.m., members of the MIT’s security team brought heavy machine guns to fend off the helicopters. Defenders of the spy headquarters and the presidential palace used shoulder-fired missiles.

After the coup was thwarted, Mr. Erdogan publicly scolded his spy agency, raising questions about the future of its chief, Mr. Fidan. The highest-ranking military official accused in the plot is a four-star general and former commander of the Turkish Air Force.

“There’s no point trying to hide or deny it, I told the head of national intelligence, there is a significant shortcoming of intelligence in all of this,” Mr. Erdogan said in a TV interview. “This kind of armed coup attempt isn’t something you can plan in 24 hours…By drawing lessons from all that has happened, we will take steps.”

Turkish intelligence officials said they did the best they could given the difficulty of collecting intelligence from a sophisticated network of plotters.

“If we hadn’t gone after this rumor and brought the coup plot forward most likely we would be dead or in prison,” a senior Turkish intelligence official said. “This was an intelligence failure that was systemic across our security apparatus, not just the MIT.”

American charter schools have become embroiled in a proxy fight between Turkish President Recep Tayyip Erdogan and Fethullah Gulen

By Ianthe Jeanne Dugan and Douglas Belkin

A global proxy war between the president of Turkey and his No. 1 nemesis played out early this year in an otherwise routine public-school board meeting in Fremont, Calif.

On the agenda during the January meeting was a pitch from the chief executive of a California charter-school chain, which had proposed opening an outpost in the Silicon Valley suburb.

Also in attendance, and bearing a long list of objections, was a lawyer representing the Republic of Turkey.

The attorney, from London-based Amsterdam & Partners LLP, “has been following us around lately” trying to block the chain’s projects, Caprice Young, chief executive of Magnolia Public Schools, told the Fremont board. “He is a representative of the Turkish government who seems to believe that we are affiliated with a religious group with whom we are not affiliated.”

Magnolia is among hundreds of targets in a battle between Turkish President Recep Tayyip Erdogan and his former political ally Fethullah Gulen , a Muslim cleric with millions of global followers, who left Turkey in 1999 and lives in Pennsylvania.

Turkish officials blame Mr. Gulen for orchestrating a July 15 coup attempt. They accuse him of trying to subvert the democratically elected government via positions his sympathizers hold in the judiciary, police and academia.

Turkey has asked the U.S. to extradite Mr. Gulen on charges unrelated to the putsch. U.S. officials have said they would consider all evidence Turkey presents as part of an extradition request; privately, many senior U.S. officials said they are skeptical of Turkey’s claims against Mr. Gulen.

Mr. Gulen’s network is hard to define. His supporters run schools and foundations around the world with clear ties to him. His links to other institutions are less clear, including to U.S. schools such as Magnolia. The chain was founded by two Gulen sympathizers and counts Gulen admirers among its teachers, said its CEO, Dr. Young. She said Magnolia has no legal, financial or governance connection with him.

Robert Amsterdam, whose firm was hired by Turkey, said he has about 25 employees and consultants fanned out around the globe to prove a theory, an effort that predated the coup attempt and has gathered momentum since. Roughly 150 schools in the U.S., and hundreds of other academic institutions and businesses around the world, he claims, channel millions of dollars annually to the Gulen movement.

“This is truly a global political and criminal movement,” said Mr. Amsterdam. “In the U.S., they’re teaching 60,000 students. I don’t know how they have time to teach when they spend so much time gaming the system.”

A Turkish embassy official in Washington referred inquiries to Mr. Amsterdam.

On a recent day, Mr. Gulen sat on a gold-colored couch in a book-lined office in a former summer camp in Saylorsburg, Pa., a Pocono Mountains town. He agreed to meet and be photographed but declined to speak, citing health concerns.

His representatives referred inquiries to Yuksel Alp Aslandogan, executive director of the Alliance for Shared Values, a nonprofit that promotes Mr. Gulen’s ideas and his “Hizmet” movement. Mr. Gulen denies involvement in the failed coup, denies trying to subvert the government and is opposed to violence, said Mr. Aslandogan. The cleric, he said, is 77 or 78 years old.

Mr. Aslandogan defended the movement, saying: “There are hundreds of businesses and NGOs within the Hizmet movement that have been legally operating around the world…and have been praised by local authorities and heads of state for their contributions to the country in which they operate.”

Some U.S. schools on Mr. Amsterdam’s hit list were founded by Gulen sympathizers but Mr. Gulen doesn’t run them, said Mr. Aslandogan, who himself helped start a school in Chicago.

‘Money laundering’

Mr. Amsterdam is aiming to tie the schools on his list to Mr. Gulen and expose what he said is a “money laundering” scheme. Some schools, he said, illegally use public funding to pay for immigration lawyers to win visas for teachers and administrators from Turkey. The schools then expect these Turkish employees to donate to the Gulenist movement, he said, and pressure them to donate to American politicians who advocate for Mr. Gulen.

The schools, he said, illustrate why Mr. Gulen should be extradited. They “give him political influence in a very big way,” he said.

Mr. Aslandogan said the schools Mr. Amsterdam accuses of impropriety “are American institutions serving American children and their parents. Any illegal or unethical action by individuals who are allegedly sympathizers of the Hizmet movement would be against the movement’s core values.”

Both camps are focused on Washington, D.C., where they are enlisting lawmakers and lobbyists to argue for or against Mr. Gulen and his causes. The Alliance, which backs Mr. Gulen, hired the Podesta Group Inc., co-founded by the chairman of Hillary Clinton’s White House campaign, John Podesta, and now run by his brother, Tony Podesta.

Mr. Gulen rose to prominence in Turkey in the 1980s with his moderate Islamic teachings combining religion, democracy and science. When Mr. Erdogan rose to power in 2002, his party and Mr. Gulen shared some goals, working closely to break the military’s political monopoly and to overhaul laws they saw as discriminating against some conservative Muslims.

Mr. Erdogan and Mr. Gulen eventually broke their alliance. The cleric accused the president of becoming dangerously authoritarian. Mr. Erdogan accused his opponent of attempting a soft coup when prosecutors and judges announced a corruption investigation against Erdogan allies. Mr. Erdogan and his allies denied the corruption allegations, and Mr. Erdogan’s government helped quash the investigation.

In December, Mr. Amsterdam helped sue Mr. Gulen in Pennsylvania federal court on behalf of a rival religious group in Turkey, claiming Mr. Gulen directed followers to carry out human-rights abuses. In June, a U.S. district judge dismissed the case, saying it was in the wrong jurisdiction. Mr. Aslandogan called the suit part of a “smear campaign.”

After the failed July putsch, Turkish authorities purged thousands of military officers, judges, prosecutors, police officers and academics over suspected Gulen ties. Mr. Erdogan is pressuring governments in Europe, Africa and Asia to shut schools founded by Gulen supporters.

Mr. Amsterdam said his team in the U.S. has been rounding up documents, filing complaints with state school administrators, interviewing students and parents and mining data on administrators and affiliates.

“We’re moving methodically from state to state. We have hit Texas, California, Ohio and Illinois. We are going to go to the Eastern Seaboard: New York, Massachusetts, New Jersey and down to Florida,” he said, sitting in a New York hotel cafe on a recent day. “We’re going to do our own whistle-stop tour.”

In Texas, Mr. Amsterdam filed a complaint this summer about the Harmony Public School network to the Texas Education Agency. He alleged that the parent company of the schools hired Gulen supporters from Turkey, paid them more than other teachers and required them to donate to politicians.

The TEA said it is reviewing the complaint to determine if it should launch a formal investigation into some of the allegations, including whether the schools gave preferences to some vendors and misused state and federal funds. Harmony denied Mr. Amsterdam’s allegations and said it is cooperating with the review.

Harmony’s CEO, Dr. Soner Tarim, called the complaints “unfounded,” “ridiculous” and “frivolous.” As in many school chains on Mr. Amsterdam’s list, one of Harmony’s founders was of Turkish descent. Harmony, with 48 schools, said 197 of its 3,545 teachers are on H-1B visas. All of them are from Turkey. It has offered Turkish as a foreign language.

Mr. Amsterdam said he is preparing a complaint against Concept Schools in the Midwest, which is on his list of charter schools with ties to Mr. Gulen. A Concept spokesman said the school chain wasn’t aware of Mr. Amsterdam’s investigation and denied Gulen ties.

At Beehive Science and Technology Academy in Utah, Assistant Principal Germaine Barnes noticed the school on a list of supposedly Gulen-linked schools. The school has no ties to Mr. Gulen, she said. “We’re being unfairly portrayed and we have no control over it.”

In Massachusetts, at least three schools are on Mr. Amsterdam’s list. Among them is Pioneer Charter School of Science, which opened in 2007 near Boston. Pioneer declined to comment. Dominic Slowey, a spokesman for the Massachusetts Charter Public School Association, wrote in an email that the three schools get erroneously linked with Mr. Gulen because they have some Turkish administrators and offer Turkish as a language option. “This keeps showing up on various websites and we keep playing Whack-a-Mole with it.”

Magnolia, the charter-school chain that proposed a school in Fremont, was founded by Gulen sympathizers who were Turkish graduate students in California, said Dr. Young, the CEO. The Los Angeles-based chain of 10 schools offers Turkish language, which Dr. Young said is in demand for State Department jobs.

Dr. Young said that some of Magnolia’s teachers are Turkish-Americans who have been influenced by Mr. Gulen, that the chain’s trustees include at least two Turkish-Americans and that the school has no affiliation to the Gulen movement. In a previous job as head of the California Charter Schools Association in 2007, she said, she joined a trip with educators and community leaders to Turkey funded by the Pacifica Institute, which supports Mr. Gulen’s ideas. She isn’t a Gulen follower, she said.

At the Fremont school-board meeting, Dr. Young came prepared. A month earlier, representatives of Magnolia had been blindsided by an Amsterdam attorney, John Martin, at a school-board meeting in Anaheim, Calif. In that meeting, Mr. Martin alleged Magnolia had improperly spent hundreds of thousands of dollars on H-1B visas to bring in Turkish teachers and said he suspected that those teachers were being forced to send money to Gulen organizations. Dr. Young denied the allegations.

In Fremont, Dr. Young, who became CEO in 2015, wanted to show the attacks were part of a larger fight. Before Dr. Young testified to her schools’ success, an employee handed out contracts showing that Turkey was paying Mr. Amsterdam’s firm $50,000 monthly. “We don’t understand it really any better than you do,” she told the group, “but I am here and happy to respond to any of the accusations.”

Mr. Martin took the podium, saying the Magnolia chain lacked transparency, overpaid external vendors for questionable services, “practices extremely poor fiscal discipline” and was tied to Mr. Gulen.

Afterward, Dr. Young and her colleagues from Magnolia “surrounded me and asked me ‘Why are you picking on the kids?’ “ Mr. Martin said. Dr. Young said only she approached him, adding: “He is telling baldfaced lies intended to hurt the children we serve.”

The Fremont board later in January denied Magnolia’s petition to start a school. In its written decision, without mentioning Mr. Martin’s assertions or Mr. Gulen as a factor, the board said Magnolia was “unlikely to successfully implement the program presented in the petition.”

Dr. Young said Magnolia asked to withdraw its petition before the rejection because the chain determined it couldn’t find an appropriate facility. Board spokesman Brian Killgore said it acted despite the withdrawal request.

In a February complaint to the California Department of Education, Mr. Amsterdam’s firm wrote that “California should not ignore the documented evidence that Magnolia has a long history of ambiguous financial practices, numerous business dealings posing conflicts of interest, all of the markers commonly associated with Gülen Organization charter networks under investigation.”

Dr. Young said the assertions are false. Magnolia lawyers have written to Mr. Amsterdam’s firm demanding it “cease-and-desist” making “false” statements.

In June, Magnolia published a release saying more than 30 alumni, parents and children had submitted a letter to the Turkish Consul General in Los Angeles “demanding the Turkish government stop spending substantial resources on high-powered lobbyists and lawyers to spread false information about their schools in an attempt to shut them down.”

A parent, Lourdes Gonzalez, said she agreed to be quoted in the release because she was furious Turkey would meddle in an American school. “We will not allow our children to be used as pawns,” she said in the release, “in a political game taking place 7,000 miles away.”

Margaret Coker and Devlin Barrett contributed to this article.

Corrections & Amplifications

An earlier version of this article misspelled Fremont schoolboard spokesman Brian Killgore’s name. (Sept. 22, 2016)

Investors who saw Turkey as a free-market beacon fear its president’s focus on rooting out internal enemies endangers financial institutions and trust in its economic stewardship

By Yeliz Candemir

Istanbul’s tightknit finance community first felt the chill of Turkey’s post-coup crackdown in late July when a senior banker was hit with a criminal complaint and stripped of his license.

Fear spread when regulators started forcing banks to hand over internal client communications, according to several people familiar with the moves.

Then, over succeeding weeks, Turkish authorities took over 496 companies, some with publicly held units, citing a hunt for coup plotters.

The moves mark a sharp reversal for a country long seen as a free-market beacon among emerging nations, thanks to President Recep Tayyip Erdogan’s embrace of pro-business policies. Turkey attracted international investors in part because of the government’s lack of meddling.

Now, investors and businesspeople say Mr. Erdogan’s relentless focus on rooting out perceived internal enemies, coupled with a consolidation of power under an emergency decree, imperil domestic financial institutions and trust in the country’s $720 billion economy. Turkey’s Parliament, dominated by Mr. Erdogan’s Justice and Development Party, or AKP, recently extended emergency powers for another three months.

“The risks are disproportionately high,” said Michael Harris, London-based global head of research at investment bank Renaissance Capital, who is recommending clients divest from Turkey. “A lot of foreign investors are understandably jittery in this environment and see these developments with worry.”

One of Turkey’s top corporate law firms was shut down following a police raid that investigators described as part of their investigation of the July 15 attempted coup. Clients are left trying to secure what they thought had been confidential corporate information.

Purges at the Capital Markets Board, meanwhile, paralyzed Turkey’s financial regulator and prevented voting on at least 25 planned debt and capital issuances for 2 ½ months until the government appointed new board members.

In such as tense atmosphere, stern words from the top can be enough to change business behavior. “There’s a disagreement between me and bankers on interest rates,” Mr. Erdogan said in an August speech. “If they try to turn [their] strength into an opportunity at a time like this, they’ll find us against them.” A dozen banks soon announced they were lowering mortgage rates.

Turkey’s economy is feeling the post-coup moves, which include tens of thousands of arrests. Its tourist industry had already been battered by a series of terrorist incidents. Moody’s Investors Service this fall cut its rating on Turkish government bonds to below investment grade, matching S&P’s long-held view. One reason Moody’s cited was concerns about the rule of law.

The Turkish lira hit a record low against the U.S. dollar in recent weeks. Assets managed by Turkey-focused equity funds have fallen by two thirds from their peak in 2013, falling from $3.7 billion to $1.3 billion at the end of September, according to data provider EPFR Global.

Economic growth is still strong by international standards but slowed to a 3.1% annual rate in the second quarter, from 4.7% in the first. The government revised its growth projection for next year to 4.4% from 5%. The International Monetary Fund pegs it at 3%.

Several Turkish government ministers said the economy remains healthy, citing growth, declining government debt and a commitment by the ruling party to structural changes such as trying to boost domestic savings.

“Cut the rating as much as you want—this is not the reality of Turkey,” Mr. Erdogan said in a speech shortly after the move by Moody’s. “Turkey continues its investments and development.” A government bond issue in October drew strong demand, the treasury said.

Deputy Prime Minister Nurettin Canikli said the coup attempt hasn’t hurt the economy or foreign investment, and that any negative sentiment “is not supported by real data.” The minister also rejected criticism that the Turkish government has interfered with the free market, saying instead that timely government action since the coup has helped bolster the economy.

The failed July coup took more than 270 lives during a night of terror that included jet fighters attacking parliament and crowds of civilians, while commandos tried to capture or kill Mr. Erdogan and Prime Minister Binali Yildirim.

In subsequent purges of the military, civil service and political opposition, more than 36,000 Turks have been arrested, according to state-run Anadolu news agency, while investigations of their possible roles in the failed coup continue.

In the finance sector, the purge has claimed 116 employees from the banking regulator, at least 30 from the Capital Markets Board and more than 1,500 from the Finance Ministry, according to government officials. These people, some fired and some suspended, are suspected of supporting the man the government accuses of masterminding the revolt—Fethullah Gulen, a U.S.- based imam who denies any involvement.

Mr. Erdogan and Mr. Gulen worked in tandem for years to break the power monopoly that a secular, pro-military elite held for decades. Mr. Gulen didn’t have a formal role in politics; his followers worked in business and the civil service, and they supported Mr. Erdogan’s party, the AKP, once it came to power in 2002.

The alliance frayed publicly in 2013. More recently, the government has dubbed Mr. Gulen as akin to a cult leader, manipulating followers to use their businesses and civil-service jobs to undermine a democratically elected parliament. Mr. Gulen has denied any wrongdoing.

More recently, the government opened criminal cases against Mr. Gulen himself. In one confidential prosecution reviewed by The Wall Street Journal, an indictment argues that a drawing of Halley’s comet on Turkish bank notes shows the imam’s malign influence over the central bank, because the comet is allegedly a secret sign to Gulen followers. The central bank declined to comment.

Mr. Gulen, who moved to the U.S. in 1999, isn’t mounting a defense in these cases, contending the charges are politically motivated. Yuksel Alp Aslandogan, executive director of a Gulen-affiliated nonprofit in New York called Alliance for Shared Values, called the comet allegation “ridiculous.”

Mr. Aslandogan has said Mr. Gulen’s followers are committed to political change in Turkey via the rule of law. Turkey has long sought Mr. Gulen’s extradition from the U.S., a request Washington says it is reviewing.

A Turkish law that predated the Gulen-Erdogan falling-out bans the dissemination of malicious information aimed at influencing markets or investors. The law carries a penalty of up to five years in prison, and one person close to Turkish finance said it long hung like a sword of Damocles over the industry.

After the July rebellion, the sword dropped.

The Capital Markets Board said on July 27 it was purging some of its members. A day earlier, it asked prosecutors to mount a criminal investigation of the head of research at Ak Investment, a unit of Turkey’s fourth-largest bank by assets, Akbank TAS, for insulting Mr. Erdogan and state institutions. The board rescinded the banker’s license for failing to “fulfill his responsibilities.”

Government officials had been infuriated, according to one person close to the finance industry, by a client note the banker sent describing theories of how the failed coup came about, including a rumor the president knew about it and let it happen to grab more power.

The Capital Markets Board didn’t respond to a request for comment, nor did the fired banker, Mert Ulker. Ak Investment declined to comment.

Several brokers and analysts in Turkey said the chill has caused them to censor their reports. One European fund manager said he canceled his subscriptions to Turkish brokerage research because it started to read like government news releases.

Political influence has become more apparent at institutions such as the central bank. Mr. Erdogan has called for repeated interest-rate cuts by the bank to underpin growth, and for seven months the bank did cut rates. Then in October, citing a currency trading near its weakest ever level, the central bank stopped. It did so one day after Mr. Erdogan’s chief economic adviser said publicly it would be all right for the bank to “skip this month.” The central bank declined to comment.

The sweeping expropriation of Turkish companies has come in waves. One of the biggest came on Sept. 9, when the government published a decree seizing the assets of two family-controlled conglomerates with about $2 billion in annual revenue apiece. The families that head them have long been under investigation on suspicion of links to Mr. Gulen, but not tried or convicted.

One company, Koza Ipek Holding, controls Turkey’s largest gold miner, publicly traded Koza Altin İsletmeleri A.S. Its chairman, Akin Ipek, has been fighting in domestic and international courts since last fall against an investigation of alleged links between his business and the Gulen movement. In an interview, Mr. Ipek denied any wrongdoing and called the seizure a step to destroy his companies.

“They accuse me, my brother, my sister and my mother, who is over 70 years old, of being members of a terrorist organization,” Mr. Ipek said. The family members “have not done this, or even purposely hurt anyone’s feelings, anytime in their lives.”

Mr. Ipek wasn’t in Turkey before the coup attempt took place and is at large. In late October, the government offered a reward for information leading to his arrest.

The government put assets of the seized companies under control of an agency known by the initials TMSF. Some will be sold off after a tender process, the agency’s president has said, with the rights of company owners protected if they are found not guilty.

“There are some companies that are directly linked to the Gulen movement, so perhaps we will sell them first,” said the official, Şakir Ercan Gul.

Mr. Canikli, the deputy prime minister, said TMSF management has helped stem losses and boost the companies’ share prices. He didn’t specify which companies he was referring to. “We have protected the rights of international investors through these interventions,” he said.

A company owned by a progovernment businessman recently said it is negotiating with TMSF to buy the shares of Koza Ipek.

At the other seized conglomerate, Boydak Holding, which has chemical, steel and energy subsidiaries, Chief Executive Memduh Boydak and Chairman Haci Boydak were arrested in March but haven’t faced trials. Neither could be reached for comment. Haci Boydak said in a July written statement that the family and their companies have no link to the Gulen network.

State-owned Turkish Airlines dismissed 211 staff members for reasons including suspected links to the Gulen movement. Turk Telekomunikasyon AS, the country’s largest landline operator and Internet-service provider, said two senior executives have resigned after being detained as part of the anti-Gulen probe. Neither Turkish Airlines nor Turk Telekom responded to requests for comment.

As for the law firm that was raided by police after the failed coup, called Yuksel Karkin Kucuk, its office telephones now go unanswered.

Margaret Coker and Georgi Kantchev contributed to this article.

Recep Tayyip Erdogan slips helicopter-borne commandos, texts the nation

By Dion Nissenbaum in Istanbul, Adam Entous in Washington and Emre Peker in Ankara

A trio of Turkish helicopters filled with rebel forces buzzed the country’s Turquoise Coast below a waxing moon early Saturday as they homed in on their target: President Recep Tayyip Erdogan.

For the first time in more than 35 years, members of Turkey’s military were trying to forcibly overthrow their government.

As the small group of elite Maroon Beret soldiers on the Turkish Riviera staged their make-or-break mission to try to capture or perhaps kill the country’s democratically elected president, it seemed as if the coup plotters had the upper hand.

In Istanbul, tanks commandeered by the rebels closed Istanbul’s international airport. Soldiers opened fire on Turkish teenagers storming their barricades on a vital bridge connecting the two sides of the city. F-16s attacked Turkey’s parliament building, and helicopters fired at the country’s intelligence headquarters. The country’s top general was detained at gunpoint by one of his top aides.

Yet the commandos who raided the resort where Mr. Erdogan had been staying missed their target. After a brief gunbattle with his presidential security force, the rebels were repelled. Before they ever arrived, Mr. Erdogan had slipped away.

When the sun came up Saturday, it was clear that the coup attempt had failed less than 12 hours after being launched.

The immediate result seems to be the opposite of what the coup leaders intended. Instead of weakening Mr. Erdogan, the coup provided a rationale for him to crack down on the military and judiciary, the two strongest bastions of Turkish society with the power to check the president’s political ambitions.

This reconstruction of the failed coup is based on interviews with Turkish and Western officials and Turkish citizens who took part in resisting the takeover. It wasn’t possible to reach the accused coup leaders, including more than two dozen top military officers, who were rounded up across the country.

The events on the ground caught the Obama administration off guard, and the Central Intelligence Agency didn’t see it coming. In the initial confusion, some U.S. officials thought the troop movements could be a response to a terrorist threat. Other officials thought it could be a sham, put on by Mr. Erdogan to strengthen his hand domestically. Intelligence officials told the White House that they believed the coup was legitimate, said U.S. officials.

On Sunday, Mr. Erdogan moved to extinguish the final flickers of armed opposition with an expanding crackdown on more than 6,000 military officers, soldiers, judges, police officers and prosecutors accused of taking part in the botched attempt to overthrow the democratically elected government.

Speaking at a massive public funeral in Istanbul for several people killed while fighting the coup attempt, the Turkish president vowed to clean the country of a “virus” that had infected Turkey.

New tactics

Mr. Erdogan, who has lost the sympathy of Western leaders who object to his broad domestic crackdown on his political foes, likely owes his survival to a counteroffensive that marshaled military might, technology and religion.

He beckoned the Turkish people to take to the streets and defend his government. In an ostentatious gambit, Mr. Erdogan sent a text message to every mobile phone in the country, a job so massive that some of the texts were still being received on Sunday.

Loudspeakers at Turkey’s mosques crackled to life in the late-night hours with a call to prayer that was widely understood by many as a call to action.

The dramatic attempt to seize power faltered as Mr. Erdogan’s call to resistance fueled huge crowds already marching against the putsch and rushing to critical locations such as parliament to show solidarity with the government.

It was the first time in Turkey’s history that its citizens rose up to prevent a military coup. Since Turkey was founded in 1923, the military has toppled the government four times. This time, the coup crumbled quickly as key military commanders rallied behind Mr. Erdogan and popular support turned decisively against those staging the coup.

Mr. Erdogan blamed the coup on a political rival, U.S.-based Turkish cleric Fethullah Gulen, and seized the moment to crack down on political opponents.

The crackdown is the start of what many diplomats, intelligence officials and analysts expect will be a broad and forceful effort to shut down Mr. Erdogan’s opponents and consolidate his already tight grip on power.

The president’s swift counterattack sparked speculation that he might have staged the coup to justify a power grab and keep the military in check.

“We might be watching a very grand theatrical performance, but I hope we’re not,” said Elif Eser, a 23-year-old finance student who opposed the coup but isn’t a supporter of Mr. Erdogan.

Turkish government officials said the coup was the work of a small faction in the military that was poised to be purged for suspected links to Mr. Gulen, now considered the country’s No. 1 enemy by Mr. Erdogan. Mr. Gulen gave a rare series of interviews to deny instigating the coup.

The botched coup began late Friday night when a small caravan of Turkish soldiers drove onto Istanbul’s Bosporus Bridge and shut down traffic heading from the Asian side of the city to its European side.

The bridge was lighted up with the blue, red and white colors of the French flag, a symbol of Turkish solidarity with France for the Bastille Day attack in Nice on Thursday that killed 84 people.

As the troops shut down traffic, people spread photos and video on social media and wondered what was going on.

Yildiray Ogur, a Turkish journalist sympathetic to Mr. Erdogan, said he believed the rumor that the troops were responding to a terrorist threat.

“No one said this was a coup d’état,” said Mr. Ogur, who lives with his wife and daughter on the Asian side of Istanbul, not far from the Bosporus Bridge.

Then it became clear that troops were closing down Istanbul’s two strategic bridges. Turkish Prime Minister Binali Yildirum appeared live on nationwide television with the first confirmation that a coup attempt was under way.

In Istanbul and Ankara, troops stormed Turkey’s state-run television offices and forced a Turkish anchor to read a statement announcing that military leaders, who called themselves the Peace at Home Council, were taking over the government. The military imposed a nationwide curfew, and armed troops moved into key locations across Turkey.

In Ankara, the fighting was more intense. Five helicopters commandeered by rebel forces repeatedly opened fire on the country’s intelligence-office gates and unsuccessfully tried to land teams of special forces in a failed attempt to capture Hakan Fidan, the powerful head of the National Intelligence Organization.

At a military base near the Syrian border, rebel pilots climbed into six F-16s and flew off to carry out airstrikes targeting Mr. Erdogan’s sprawling presidential compound and Turkey’s parliament building.

As the coup unfolded with apparent ease, many people began to wonder about the fate of Mr. Erdogan. People familiar with the situation said the coup plotters decided to strike while he was staying at the Grand Yazici Club Turban on the outskirts of the Mediterranean resort town of Marmaris.

‘Go to the streets’

Mr. Erdogan’s security detail decided to move the president to another hotel nearby for his protection. Then he broke his silence to try to rally supporters.

He used the FaceTime app to appear in an extraordinary interview on CNNTurk, urging Turks to resist while the anchorwoman held her phone up to the camera. “Go to the streets and give them their answer,” Mr. Erdogan said. “I am coming to a square in Ankara.”

Mr. Erdogan’s appearance created the impression that he was in trouble and galvanized supporters across Turkey, who flooded the streets to take on the military. Soon after he spoke, loudspeakers at thousands of mosques came to life with an unusual call to prayer that was clearly understood to be a rallying cry for Mr. Erdogan’s supporters.

Mehmet Görmez, Turkey’s president of religious affairs, ordered thousands of imams to recite prayers known as “sela,” ordinarily reserved for funerals and special religious occasions. When issued at other times, the prayers act as a call to arms for the Islamic community.

“When I heard the sela, I prayed and took to the streets,” said a teenage girl who was standing guard outside the presidential palace Sunday.

Soon, protesters were wrestling rebel soldiers in Istanbul’s Taksim Square and lying down in front of tanks at the city airport. Outside the presidential palace, demonstrators picked up sticks and rocks to take on tanks trying to establish control.

One protester was shot in the stomach when he climbed on top of a tank, said Erol Cam, 49, who joined thousands of others gathering against the coup.

As angry mobs squared off against the troops, some soldiers said they thought they were participating in a military drill, Mr. Cam said. Police guards at the palace tried to calm the people, with many believing that the soldiers had been tricked, he added.

Soldiers shot demonstrators outside Ankara’s police headquarters. Helicopters opened fire on Istanbul’s Bosporus Bridge, where troops shot at demonstrators who marched on their barricades, killing one of Mr. Erdogan’s top political allies and his 16-year-old son.

For many Turks, Mr. Erdogan’s appeal and the public response signaled the beginning of the end of the coup.

While coup leaders tried to project that they were in control, they weren’t. The military was split, and the coup leaders had led away Turkey’s top general at gunpoint. There appeared to be internal splits in key military units. Many appeared to lay down their weapons in the face of widespread public opposition. Perhaps most important, Mr. Erdogan wasn’t in custody.

When the elite commandos in their three Sikorsky helicopters landed in Marmaris, clashes broke out with members of the president’s security team and local police. A Turkish official said one police officer and a member of Mr. Erdogan’s presidential security detail were killed in the fighting.

Mr. Erdogan’s security detail had already spirited him to safety. Commandos who came for Mr. Erdogan pulled back to their helicopters, one of which malfunctioned, and then took off empty-handed.

While in the air, the aircraft carrying Mr. Erdogan and his small contingent was approached by what they believed were hostile Turkish fighter planes.

The arrival of the planes created panic on Mr. Erdogan’s plane because of concerns that the fighter pilots might be under orders to launch missiles to take down the plane or to try to force it to land so he could be arrested.

The fighters flew close by and seemed to be under orders to follow Mr. Erdogan’s plane.

Military commanders loyal to Mr. Erdogan dispatched their own fighter planes to rendezvous with his aircraft. Once those fighters arrived to escort the Turkish president’s plane, the hostile fighter planes pulled back.

Across the country, Turks found uncommon unity in opposing the coup. All of the country’s political parties, even bitter rivals of Mr. Erdogan, denounced the military takeover.

In Ankara, jets and helicopters carried out repeated attacks on the parliament building, causing significant damage. Visitors’ center windows were mostly shattered, and the buildings facade bore marks of bullet fire and shrapnel. The bombardment wrecked the main hall of parliament and destroyed the prime minister’s office.

Turkish officials said the rebel jet fighters relied on two refueling tankers based at Incirlik Air Base, where the U.S.- led coalition against Islamic State carries out daily airstrikes against forces in Syria and Iraq.

As dawn approached Saturday, Mr. Erdogan landed at Istanbul’s Atatürk International Airport, where throngs of supporters overwhelmed soldiers and greeted the president as he stepped off the plane. Even though fighting intensified, the coup seemed to be crumbling.

But the coup leaders weren’t ready to give up. Shortly before 6:30 a.m., rebel jets dropped at least two bombs that landed just outside the presidential palace in Ankara. The ground shook as plumes of smoke filled the sky. Scores of civilians were wounded, said Mr. Cam, who was standing about 250 yards from one strike.

One senior Turkish official said citizens from across the political spectrum could never have imagined the military would open fire on civilians or attack the biggest symbol of their democracy.

In none of Turkey’s previous coups “did the army attack civilian protesters or the symbol of our nation,” the official said. “That was the end.”

Ayla Albayrak contributed to this article.

Erdogan’s iron-fisted rule is pulling his country away from the West and into the troubles of the Middle East

By Yaroslav Trofimov

In 1910, during a war against rebels in remote Yemen, a young officer of the Ottoman Empire liked to entertain his soldiers with music: French and Italian operas that he played every night on a gramophone in the desert.

The youthful musical preferences of Ismet Inonu—who would become president of Turkey some three decades later—were no mere personal quirk. Ever since the mid-19th century, when a series of reforms brought elections, civil rights and modern government institutions to the decaying Ottoman Empire, Turkey’s ruling elites had looked to the West as the standard of enlightenment and civilization.

Mustafa Kemal Atatürk, the secularist army officer who founded modern Turkey in 1923, sought to sever his land’s ancient bonds to the Middle East. A revolutionary determined to transform everyday life, Atatürk introduced Latin letters and the Swiss Civil Code to replace Arabic script and Islamic Shariah law. This longstanding orientation to the West has made Turkey a rare example of a major Muslim country that is also a prosperous, stable democracy (and, since 1952, a member of NATO).

Today that tradition is under attack as never before. Nearly a century after the Ottoman Empire gave way to today’s Turkish republic, a tectonic shift is under way. Under President Recep Tayyip Erdogan’s iron-fisted rule, Turkey is drifting away from its historic Western allies in perhaps one of the most significant geopolitical realignments of our age.

Mr. Erdogan’s Turkey has come to look increasingly like just another troubled corner of the Middle East. And, many Turks and Westerners fear, the country is becoming infected with the same sicknesses—intolerance, autocracy, repression—that have poisoned the region for decades.

Early on, Mr. Erdogan—who has held de facto power since 2002—was widely hailed as a principled democrat. In recent years, however, he has grown aggressively averse to dissent, and in the wake of a failed coup attempt in July, he has unleashed an unprecedented crackdown. He is now demanding constitutional changes that would give him near-absolute authority and let him remain at the helm of this country of 80 million people until 2029.

“Erdogan’s real aim is to take Turkey out of the Western bloc, out of the civilized world, and to turn Turkey into a Middle Eastern country where he can continue to rule without any obstacles,” said Kemal Kilicdaroglu, the head of Turkey’s biggest opposition party, the Republican People’s Party, or CHP. “He wants to turn Turkey into a country where there is no secularism and where people are divided along their ethnic identity and their beliefs. It is becoming a nation that faces internal conflict, just as we have seen in Iraq, Syria or Libya.”

Turkish officials retort that the West is abandoning their country, not the other way around. Mr. Erdogan recently blasted the European Union for its “meaningless hostility” as decadeslong talks on Turkish membership in the bloc neared collapse. “Neither the European Union nor the European countries that are on the brink of falling into the clutches of racism can exclude Turkey from Europe,” said Mr. Erdogan. “We are not a guest but a host in Europe.”

Members of Mr. Erdogan’s Justice and Development Party, known as the AKP, often point out that, as the July coup unfolded, Russian President Vladimir Putin made the first call to express support for Mr. Erdogan, hours before President Barack Obama weighed in. That night, many other Western politicians kept silent or even cheered for the putschists.

“It’s not Turkey that is distancing itself from Europe. It’s Europe that is distancing itself from the axis of democracy. For them, democracy is when we don’t elect Erdogan, and dictatorship is when we elect him,” said Mehmet Metiner, a prominent AKP lawmaker. “Turkish democracy is better than Western democracy.”

Such statements cause many Western officials to shake their heads in despair while pointing to Mr. Erdogan’s increasingly authoritarian record. Some 150 journalists critical of the government are currently behind bars in Turkey, which jails more journalists than any other country in the world, according to Reporters Without Borders, a media-freedom group. Tens of thousands of Turks suspected of opposition or disloyalty—from teachers to bureaucrats to police officers—lost their jobs in purges that followed the July coup attempt. And last month, Mr. Erdogan’s government detained the co-heads of one of the country’s three main opposition parties.

Meanwhile, Turkey’s yearlong campaign against a renewed insurgency by restive Kurds has ravaged the country’s southeast. Dozens of towns and neighborhoods have been flattened in bloody urban warfare between government forces and the Kurdistan Workers’ Party, or PKK, which both Ankara and Washington consider a terrorist organization. A separate bombing spree by Islamic State has hit major Turkish cities.

A month after the July coup attempt, Mr. Erdogan also unleashed a war abroad: Turkish troops invaded northern Syria, where they are fighting alongside Sunni Arab rebels against both Islamic State and a Kurdish militia linked to the PKK. Mr. Erdogan has also threatened military intervention in Iraq, and Turkish troops are already deployed near Mosul, most of which remains in the clutches of Islamic State.

With Turkey in the headlines for all the wrong reasons, the country’s tourism industry has withered, the currency has sunk, and the Turkish economic miracle that had long fueled Mr. Erdogan’s popularity has begun to fizzle.

The Islamic world once envied Turkey’s achievements, but few Muslim leaders now look to it as a role model. Yasar Yakis, a founding member of the AKP who served as Turkey’s foreign minister in the early days of Mr. Erdogan’s rule, recalls wistfully that, as recently as 2011, revolutionary leaders in Tunisia sought to calm fears about possible human-rights abuses by promising to follow Turkey’s example of blending democracy and Islam. Today, he says, many Turks are envious of Tunisia—the lone Arab state to overthrow its autocrat during the 2011 revolutions and remain a budding democracy. “Tunisia was inspired by Turkey, and now we have to be inspired by Tunisia,” Mr. Yakis says.

As Turkey has grown alienated from the West, Mr. Erdogan has moved toward strategic alliances with powers that won’t criticize his newly authoritarian ways. Last month, he raised the prospect of Turkey’s joining the Shanghai Cooperation Organization, a security and political pact that unites Russia, China and the mostly Turkic Central Asian states. Full participation in that group probably wouldn’t be compatible with Turkey’s continued membership in NATO.

As part of his rapprochement with Russia, Mr. Erdogan has already softened his stance on the raging Syrian war. Most notably, he has tacitly acquiesced to the Russian-backed drive by Syrian dictator Bashar al-Assad to retake rebel-held sections of Aleppo, at an enormous cost to vulnerable civilians.

Though Mr. Erdogan began his political life as an Islamist, that ideology is not necessarily animating Turkey’s shift. “He knows very well he cannot change Turkey to an Islamic state. He is afraid of the country becoming like Saudi Arabia; this is his nightmare,” said Ali Saydam, a columnist for the pro-AKP Yeni Safak newspaper.

Insofar as any ideology can be ascribed to the protean Mr. Erdogan, many Turks say, it is his resentment—widely shared in the developing world—at being bullied by the planet’s major powers. He has repeatedly used the slogan “The World Is Bigger Than Five,” a reference to the five permanent members of the U.N. Security Council.

That suspicion of big global powers is unlikely to recede during Donald Trump’s presidency, but Mr. Erdogan seems to be trying a balancing act with the incoming administration. He criticized Mr. Trump’s call last year to bar Muslims from entering the U.S. and even suggested renaming the Trump Towers in Istanbul in response. But after Mr. Trump praised the Turkish president’s demeanor during the July coup attempt, Mr. Erdogan has been careful not to speak ill of the American president-elect.

Mr. Erdogan may see welcome changes in the new administration. As the coup unfolded in July, Michael Flynn, the retired general who is Mr. Trump’s designated national security adviser, made public remarks supportive of the putschists, who he appeared to believe were driven by a secularist agenda. But after Mr. Erdogan accused a Turkish cleric living in Pennsylvania, Fethullah Gulen, of masterminding the coup, Gen. Flynn wrote an op-ed in the Hill urging the extradition of the “shady Islamic mullah” (even though the matter is still under Justice Department review) and saying that the U.S. needs “to see the world from Turkey’s perspective.”

Turkey’s realignment is just part of a global upheaval that includes Britain’s exit from the European Union and Mr. Trump’s election, said Dogu Perincek, the head of Turkey’s small nationalist Vatan party. Ankara’s relationship with Washington will inevitably loosen as America turns inward and the U.S.-dominated postwar world order fades away, he predicted. “Turkey is separating from the Atlantic system and is going to have its place within the Eurasian system,” Mr. Perincek said.

Turkish officials say that Turkey is simply restoring some natural balance in its international relationships and adapting to the rising economic clout of non-Western states such as China. Ankara’s new policy “doesn’t mean that Turkey doesn’t want to continue to work with the West and that it wants to change its path to the East,” said Mr. Erdogan’s senior adviser, Reha Denemec. “But Turkey is transformed. For almost 70 years, we had forgotten our old friends, the countries in the East, and we now have to also collaborate with them.”

The West, he added, shouldn’t hold Mr. Erdogan to the same standards as the leader of a peaceful land in a tranquil neighborhood: “If you criticize Mr. Erdogan with the home parameters of a country like Austria, where there are no bombing attacks, no terrorist attacks, no neighbors like Syria, Iraq, or Russia, where it is easy to run, where there is no coup, you are making a big mistake.”

Mr. Erdogan didn’t always bristle at being judged by European standards. He pushed hard to integrate Turkey into Europe after coming to power in 2002, bringing Turkey closer to EU membership than it had been since first applying to join the club in 1987.

The AKP then saw Europe as a useful ally against Turkey’s secularist security establishment, which worried about the party’s Islamist roots. Using the EU membership process, which required Turkey to comply with European norms, the AKP enacted more liberal laws that weakened the power of military leaders who could have threatened Mr. Erdogan’s rule.

The reforms gave more freedom to Turkey’s more conservative Muslim women, who could now wear a veil in universities and government offices, and to Turkey’s often marginalized Kurdish minority, which was finally allowed to use its own language. At the time, even Turkey’s liberals and human-rights defenders praised Mr. Erdogan and the AKP.

“We thought at the beginning that he honestly meant to wage a fight against the militarist structure in Turkey. We believed that,” said Eren Keskin, a prominent lawyer who coheads the Turkish Human Rights Association—and now faces a lengthy prison term for alleged offenses against Mr. Erdogan’s state.

But several EU member states, including France and Germany, were uneasy about accepting a large Muslim country. As the Turks were kept waiting in the antechamber, poorer Christian-majority countries such as Bulgaria were fast-tracked for membership. The post-coup crackdown only made matters worse. In November, the European Parliament overwhelmingly voted to suspend the stalled membership talks.

Over the past decade, disillusionment with the West prompted Mr. Erdogan to embark on a “neo-Ottoman” foreign policy of seeking to restore Turkey’s historical trade and political ties to the Middle East—and to become the region’s informal leader. The effort seemed to succeed briefly after the 2011 Arab Spring, when Islamist parties friendly to the AKP rose to power in several countries. But Turkey’s policy floundered after Egypt’s democratically elected Muslim Brotherhood government was ousted in 2013 in a military coup and Ankara became more embroiled in the intractable civil war in neighboring Syria.

Still, Turkey remained relatively free, thanks to continuing challenges to Mr. Erdogan’s authority from the judiciary and the rival Islamist movement led by Mr. Gulen, whose supporters in law enforcement pushed through corruption investigations against the president’s inner circle. A turning point came in June 2015, when the AKP lost its parliamentary majority for the first time in 13 years—in part because many Kurds who once voted for Mr. Erdogan embraced the new, pro-Kurdish Peoples’ Democratic Party and its charismatic leader, Selahattin Demirtas.

But Mr. Erdogan, faced with the prospect of having to form a coalition government, decided that he didn’t want to share power. Instead, he used a series of cease-fire violations by PKK guerrillas to launch an all-out onslaught against Kurdish militants. The move appealed enough to hard-line nationalist voters that Mr. Erdogan was able to regain an absolute majority of parliamentary seats in snap elections that he called in November 2015. Mr. Demirtas, for his part, was jailed last month, alongside other Kurdish leaders.

Osman Can, a one-time AKP lawmaker and former constitutional court justice who worked on the coalition talks, is alarmed by what he sees ahead. “The institutions have failed,” he said. “We have no institutions that can provide rational decisions on policy. Everything is now in the hands of one man, Mr. Erdogan, and when just one man is deciding everything, there is no future for Turkey.”