Daniel Etter for The New York Times  Pupils at a school in Istanbul run by the Gulen movement sang Turkeyâs national anthem recently. The movement has millions of followers and schools in 140 countries.  ISTANBUL — When Ahmet Sik was jailed last year on charges of plotting to overthrow the government, he had little doubt that a secretive movement linked to a reclusive imam living in the United States was behind his arrest.  “If you touch them you get burned,” a gaunt and defiant Mr. Sik said in an interview in March at his apartment here, just days after being released from more than a year in jail. “Whether you are a journalist, an intellectual or a human rights activist, if you dare to criticize them you are accused of being a drug dealer or a terrorist.”  Mr. Sik’s transgression, he said, was to write a book, “The Army of the Imam.” It chronicles how the followers of the imam, Fethullah Gulen, have proliferated within the police and the judiciary, working behind the scenes to become one of Turkey’s most powerful political forces — and, he contends, one of its most ruthless, smearing opponents and silencing dissenters.  The case quickly became among the most prominent of dozens of prosecutions that critics say are being driven by the followers of Mr. Gulen, 70, a charismatic preacher who leads one of the most influential Islamic movements in the world, with millions of followers and schools in 140 countries. He has long advocated tolerance, peace and interfaith dialogue, drawing on the traditions of Sufism, a mystical strain of Islam generally viewed as being moderate.  But the movement’s stealthy expansion of power — as well as its tactics and lack of transparency — is now drawing accusations that Mr. Gulen’s supporters are using their influence in Turkey’s courts and police and intelligence services to engage in witch hunts against opponents with the aim of creating a more conservative Islamic Turkey. Critics say the agenda is threatening the government’s democratic credentials just as Turkey steps forward as a regional power.  “We are troubled by the secretive nature of the Gulen movement, all the smoke and mirrors,” said a senior American official, who requested anonymity to avoid breaching diplomatic protocol. “It is clear they want influence and power. We are concerned there is a hidden agenda to challenge secular Turkey and guide the country in a more Islamic direction.”  The movement has strong affiliations or sympathy in powerful parts of Turkey’s news media, including the country’s largest daily newspaper, Zaman, and, Turkish analysts say, among at least several dozen members of its 550-seat Parliament, with support extending to the highest levels of government.  With its extensive influence in the media and a small army of grass-roots supporters, the Gulen movement has provided indispensable support to the conservative, Islam-inspired government of Prime Minister Recep Tayyip Erdogan. Some officials and analysts suspect that some elements within the Gulen movement have served as a stalking-horse for the government, which has benefited, too, as the Gulen-affiliated media have attacked common opponents and backed trials that Mr. Erdogan has publicly supported.  But the relationship between Mr. Erdogan and Mr. Gulen has sometimes been tense, with the prime minster, a mercurial and populist leader, sensitive to any challenges to his authority. Analysts say that in recent months Mr. Erdogan and other members of his Justice and Development Party have grown increasingly wary, as high-profile arrests of critics of the Gulen movement have embarrassed the government. There is growing talk of a power struggle.  A culture of fear surrounding the so-called Gulenists, however exaggerated, is so endemic that few here will talk openly about them on the telephone, fearing that their conversations are being recorded and that there will be reprisals.  Ayse Bohurler, a founding member of the Justice and Development Party, said that the lack of transparency and clear organizational structure made it impossible to hold the group accountable. “There is no reference point; they are kicking in the shadows,” Ms. Bohurler said. “They are everywhere and nowhere.”  Mr. Gulen rarely gives interviews, and he declined a request for this article. But Mustafa Yesil, president of the Journalists and Writers Foundation, a group based in Istanbul that is affiliated with the movement, described the Gulenists as a “civic movement” with no political aspirations. If sympathizers of the movement are well represented in Turkey’s state bureaucracy and the police, Mr. Yesil said, their presence is based on merit.  “The old guard feel squeezed because their space is getting smaller, and they are sending the bill to the movement,” Mr. Yesil said.
Fethullah Gulen has long advocated a moderate, tolerant brand of Islam, but critics say his movement is persecuting opponents and working toward a conservative Islamic Turkey.