Monica E. Witt, a former United States Air Force intelligence specialist, made her way through the gleaming doors and majestic lobby of one of Tehran’s largest luxury hotels in 2013, on her way to a conference that was all about bashing American culture.
There, in a crowd filled with fringe academics, Holocaust deniers and the lover of the terrorist known as Carlos the Jackal, Ms. Witt at last found herself among people as critical of her country as she was.
“What she said was she had been involved in horrific war crimes with the Air Force,” said Kevin Barrett, a controversial scholar of Islam who had an extensive conversation with Ms. Witt in the gilded lobby of the Parsian Azadi hotel. “And she just felt really bad about it.”
Less than seven months after the Tehran conference, according to an indictment unsealed on Wednesday, Ms. Witt defected and became a spy for the Iranian security service. It was the climax of a radicalization that was rooted in Ms. Witt’s military service and that accelerated while she was in graduate school. The F.B.I., around the time Ms. Witt earned her graduate degree, alerted her that Iran’s intelligence service had its eye on her.
“There weren’t warning signs in terms of ‘go to authorities’ warning signs,” said Cory Ellis, who knew Ms. Witt when they were enrolled in the same master’s degree program at George Washington University. Still, he said, she did not hide her strong feelings against American foreign policy. “Everyone just kind of sat and watched it.”
American law enforcement and intelligence officials have been left to cope with the repercussions of what several of them have publicly described as a “betrayal” by Ms. Witt, now 39. Officials suspect she remains in Iran, out of reach of American law enforcement.
Former intelligence officials familiar with the case described the damage to national security as severe, in part because she is suspected of revealing the names of double agents run by the United States, and the American authorities have struggled to conclude exactly why she turned on her country.
But an examination of Ms. Witt’s background, along with public records and interviews with friends, acquaintances and current and former American officials, shows that her enchantment with Middle Eastern culture turned into active treachery against her home country and may have made her an enticing prospect for an avowed adversary of Washington.
More than a year before the United States said she became a spy, the authorities said, Ms. Witt met with Marzieh Hashemi, a Louisiana-born journalist who had moved to Iran and was regarded by the American government as a so-called spotter: a recruiter for a foreign intelligence service.
“She wasn’t in it for the money; this wasn’t a fee-for-task thing,” Douglas H. Wise, who was deputy director of the Defense Intelligence Agency, said of Ms. Witt. “At some point, she took an ideological left turn to become aligned with the Persians.”
By the time she did, she had spent much of her adult life in a shadowy world.
Ms. Witt, who was born in El Paso, enlisted in the Air Force and entered active duty about eight months after her 18th birthday, in 1997, just after the death of her mother. Slender, with straight brown hair, she was quickly assigned to the crew of an RC-135 spy plane — a jet packed with reconnaissance equipment.
She first deployed to the Middle East in 2002, when she was sent to Saudi Arabia. Other missions followed: to Diego Garcia, a British atoll in the Indian Ocean of immense strategic value to Western militaries, and to Greece. In 2005, she served an almost six-month deployment to Iraq at a time of growing sectarian violence and insurgent attacks. The next year, she began a roughly seven-month tour in Qatar.
In June 2008, the same month she left the Air Force, she earned a bachelor’s degree from the University of Maryland University College, and later worked for two national security contractors. Eventually, she entered graduate school at George Washington, an academic proving ground for aspiring diplomats and researchers near the State Department’s headquarters.
Members of Ms. Witt’s family, who did not respond to messages after her indictment was announced, said little about her to neighbors. According to Mr. Ellis, her classmate, she seemed to have drifted from her relatives.
Connie Shields, who lives near Ms. Witt’s father, Harry Witt, in Longwood, Fla., said there had been little discussion of Ms. Witt’s intelligence work. “It just was not talked about,” Ms. Shields said. “I don’t think Harry knew too much about where she was or what she was doing.”
She was only somewhat less mysterious at George Washington. To classmates, many of whom were far younger than her, she appeared shaken by her time in Iraq, withdrawn, even alienated.
She was quiet in lectures, but sometimes hung around afterward, talking about her time in the military.
“She would talk about how she couldn’t sleep at night, the stuff she saw and was a part of,” said Mr. Ellis. Ms. Witt, he remembered, would mention drone strikes, extrajudicial killings and atrocities against children, all of which she claimed her colleagues in the military would brag about. She seemed distressed by what she called “gross incompetence” by her superiors during her time abroad.
Her finances were a mess. In 2011, she moved into a dilapidated, low-income building in Falls Church, Va., a Washington suburb, according to public records. The building was across the street from a cremation service and is full of dim, cramped hallways with heavily stained carpeting and security cameras perched just below the ceiling.
A former law enforcement official said that at some point she became homeless.
Other students who knew her described conversations in which she said she felt like she didn’t fit in and was conflicted about identity and belonging.
She did, though, have a clear interest in Iran — memorable, but unremarkable, for a student in a Middle East studies program — and a working command of Farsi, which she had begun to learn while in the military.
She had also taken an interest in Islam during her time in the Air Force, and had begun to study the religion when she was in Iraq, according to an interview she gave to an Iranian news agency.
But it was in 2012, after she returned from a trip to Tehran to attend a conference, that she transformed.
Suddenly she was wearing a hijab, her classmates said, announcing her conversion to Islam and talking excitedly about Iran like a tourist. Her shift struck her classmates as extreme.
The conference, called “Hollywoodism,” was focused on how the American film industry maligned Iranian culture on the big screen. She had not been invited but was allowed to speak anyway, according to an organizer.
“At the time she seemed suspicious to me. We try to be transparent, but it was completely unclear where she came from,” said Nader Talebzadeh, an Iranian documentarian who is critical of the West and helped organize the conference. “She was bouncing around the region, said she was converted to Islam, but I have met many people who did so. She didn’t come across as genuine.”
Upon her return to Washington, she delivered her capstone presentation before a panel of professors. It did not go well.
Mr. Ellis, who attended, recalled Ms. Witt’s argument as a “love letter to Iran,” and said she asserted that the country would only use a nuclear weapon in self-defense. Faculty members hit her hard with questions, Mr. Ellis recalled, and Ms. Witt appeared to shrink in response.
“She was almost offended that the assumption that Iran was a peace-loving nation would even be questioned,” he said. “She was visibly upset.”
A spokesman for George Washington confirmed that Ms. Witt earned a graduate degree in 2012, but declined to discuss her time at the university. Faculty members did not respond to messages.
The same month as her commencement, F.B.I. agents contacted Ms. Witt, according to the indictment against her. They brought a grave warning: Iran’s intelligence services considered her a target for recruitment. Ms. Witt rebuffed the agents’ concerns and told them that, if she returned to Iran, “she would refuse to provide any information” about her work with the Air Force.
Within about a month, the government said, Ms. Witt was hired by Ms. Hashemi “in connection with the filming of an anti-American propaganda film that was later aired in Iran.” By February 2013, Ms. Witt was back in Tehran for another iteration of “Hollywoodism.”
Speaking to the Iranian news agency at the time, she explained that she had been a Christian, though not religious, and had first studied Islam to help her understand American missions in the Middle East. “I believed it would help me to better confront the enemy,” she said, according to the report.
Soon, though, she was captivated. “I became so interested in the Quran that I studied it every night,” she said. “I realized that despite what the U.S. military had told us, Islam is not a violent and aggressive religion.”
She also met with representatives of the Islamic Revolutionary Guard Corps, according to the Justice Department, and was filmed criticizing the United States government.
“They were very sophisticated, and they’ve got young people, well-appearing people speaking English beautifully,” said Mike Gravel, a former Democratic senator from Alaska who attended the conference and himself met three times with Iranian intelligence officials. “They’re equipped to do the job of intelligence work, and if they find vulnerable people, they just capitalize on it.”
Ms. Witt did not make much of an impression on some others who met her in Iran.
“There wasn’t much that stood out to me at the time,” said Sean Stone, a son of the filmmaker Oliver Stone, who said he had twice spoken to American investigators about Ms. Witt, whom he met in Iran at the conference in 2012. “When the F.B.I. contacted me, I didn’t even remember who she was.”
In the months after the 2013 conference, Ms. Witt was in close touch with Ms. Hashemi as she traveled to Afghanistan and elsewhere, while she struggled to get a visa to return to Iran.
Finally, on Aug. 28, when the visa came through, Ms. Witt sent a message with a smiley-face emoji to Ms. Hashemi, just as she was preparing to fly to Tehran.
“I’m signing off and heading out!” she wrote. “Coming home.”