Formerly allies, Erdoğan made a definitive break with Gülen's and Hizmet in 2013. Erdoğan now blames Gülen's and Hizmet for the failed July coup attempt against his government.
Rodrik's argument in that post:
I don’t think Gulen is a tool of the U.S. or has received support from the U.S. for its clandestine operations. But it is possible that some elements within the U.S. national security apparatus think Gulen furthers their agenda, is worth protecting on U.S. soil, and have so far prevailed on other voices in the establishment with different views. Regardless, the U.S. needs to seriously reconsider its attitude towards Gulen and his movement.
However, on Gülen's role in the coup itself, he writes that "the Turkish government’s claim that Gulen was behind the coup ... is largely justified." The link there is to a previous post of his, "Is Fethullah Gülen behind Turkey's coup? (with update)" 07/23/2016.
Rokrik dismisses suspicions about how Gülen got permanent residence in the US and the assumption that Hizmet could not have mounted an operation like the July coup attempt without active US support.
However, he does cite this circumstantial evidence for some kind of "tacit" US support for Gülen's movement over the years since he immigrated into the US in 1999:
Judging by Wikileaks cables, U.S. diplomats in Turkey were exceptionally knowledgeable about Gulenist activities. These cables are in fact a goldmine of information on the Gulen movement. Form these we learn, among others, about the elaborate ruses used by Gulenist sympathizers to infiltrate the Turkish army, Gulen’s request for support from the Jewish Rabbinate’s during his green card application, and the attempt by sympathizers within the Turkish national police to get a “clean bill of health” for Gulen from the U.S. consulate in Istanbul. We also learn that even in the heyday of their alliance, Gulenists presciently regarded Erdogan as a liability.And he cautions at the end:
Perhaps of more direct interest to the U.S., foreign service officers have long been aware that many Turks have been obtaining visas under false pretenses, with the ultimate aim of ending up as teachers in Gulen’s charter schools. Yet apparently nothing was ever done to stop this flow, nor to hold the movement to account. A ridiculous number of H-1B visas have been issued to Turkish teachers in these schools. One naturally wonders why the U.S. administration never clamped down on the Gulen movement for apparent visa fraud.
The same question arises with respect to the widespread pattern of financial improprieties that has been uncovered in Gulen’s charter schools. A whistleblower has provided evidence that Turkish teachers are required to kick back a portion of their salary to the movement. The FBI has seized documents revealing preferential awarding of contracts to Turkish-connected businesses. Such improprieties are apparently still under investigation. But the slow pace at which the government has moved does make one suspect that there is no overwhelming desire to bring Gulen to justice.
Gulen typically defends himself against such charges by saying that the schools are run by sympathizers and are not directly under his control. Yet the fact is that he took direct credit for the schools in his green card application, saying he had overseen their establishment.
Then there is the Sledgehammer case, which has the Gulen movement’s fingerprints all over it. This and the closely related Ergenekon trials did untold damage to the military of U.S.’ Nato ally. The jailing of hundreds of officers, including a former chief of staff, sowed a climate of fear and suspicion within the army and sapped military morale. Perhaps the U.S. was bamboozled, like many others, early on about these trials. But by now it should know that these sham trials were launched and stage managed by Gulenists. American officials have been quick to complain in public about the damage the post-coup purge has done to Turkish military capabilities. Yet there was not a peep from them during the Ergenekon and Sledgehammer witch hunts; and nor has the U.S. administration expressed any discontent about the Gulen movement’s role in them since.
It is very unlikely that Gulen would receive a fair trial in Turkey. So the U.S. has a legitimate ground for not extraditing him. But the U.S. foreign policy establishment would be making a very big mistake if they simply dismissed the calls from Turkey about Gulen’s complicity. It is easy for the U.S. to hide behind Erdogan’s clampdown and the ill treatment of the putschists. But the U.S. has considerable explaining to do too.Weeks before the coup attempt, Stephanie Saul wrote about some of Gülen's activities in the US, Charter Schools Tied to Turkey Grow in Texas New York Times 06/06/2016:
[A]n examination by The New York Times of the Harmony Schools in Texas casts light on ... the way they spend public money. And it raises questions about whether, ultimately, the schools are using taxpayer dollars to benefit the Gulen movement — by giving business to Gulen followers, or through financial arrangements with local foundations that promote Gulen teachings and Turkish culture. ...
Harmony Schools officials say they scrupulously avoid teaching about religion, and they deny any official connection to the Gulen movement. The say their goal in starting charter schools — publicly financed schools that operate independently from public school districts — has been to foster educational achievement, especially in science and math, where American students so often falter. ...
... records show that virtually all recent construction and renovation work has been done by Turkish-owned contractors. Several established local companies said they had lost out even after bidding several hundred thousand dollars lower.
“It kind of boils my blood a little bit, all the money that was spent, when I know it could have been done for less,” said Deborah Jones, an owner of daj Construction, one of four lower bidders who failed to win a recent contract for a school renovation in the Austin area.
Harmony’s history underscores the vast latitude that many charter school systems have been granted to spend public funds. While the degree of oversight varies widely from state to state, the rush to approve charter schools has meant that some barely monitor charter school operations.