WASHINGTON — He was the “American Taliban” captured during the invasion of Afghanistan in the fall of 2001. Pictures showed him as a gaunt, filthy 20-year-old held in the aftermath of a prison uprising that claimed the first United States casualty of the war, a 32-year-old C.I.A. officer named Johnny Micheal Spann.
On Thursday, that captive, John Walker Lindh, is scheduled to leave a federal prison in Terre Haute, Ind., released on probation after serving 17 years of a 20-year sentence for providing support to the Taliban.
The case of Mr. Lindh, who converted from Catholicism to Islam at 16 and first left his California home at 17 to study Arabic in Yemen more than three years before the Sept. 11, 2001, terrorist attacks, has stirred questions and controversy from the start. His journey took him to Pakistan in 2000 and later to Afghanistan, where he spent time at a Qaeda training camp as a Taliban volunteer.
The government has characterized Mr. Lindh in recent years as holding on to extremist views, and his release has now brought objections from Mr. Spann’s family and elected officials and raised questions about how he can be safely reintegrated into society without some kind of formal government program for rehabilitating former jihadists.
“What training is provided to parole officers or supporting nongovernmental partners to recognize the signs of violent radicalization and recidivism?” Senators Richard C. Shelby of Alabama, a Republican, and Maggie Hassan of New Hampshire, a Democrat, wrote in a letter last week to Hugh J. Hurwitz, the acting Bureau of Prisons director, questioning the wisdom of Mr. Lindh’s release.
Mr. Lindh, now 38, his parents, lawyers and prosecutors all declined to discuss where he will live or his other plans after prison, where he has been described as a studious, standoffish prisoner. In 2012, he joined an American Civil Liberties Union lawsuit that won the right for Muslim prisoners at Terre Haute’s high-security Communications Management Unit to pray in groups.
As an American citizen, he was tried in federal court, unlike citizens of other countries who were also picked up in Afghanistan and Pakistan but who ended up in the military prison at Guantánamo Bay, Cuba. At his sentencing in October 2002, he condemned “terrorism on every level, unequivocally,” said he made a mistake by joining the Taliban and denounced Osama bin Laden’s terrorist attacks as “completely against Islam.”
But two leaked United States government intelligence counterterrorist assessments first published by Foreign Policy magazine in 2017 cast Mr. Lindh in a different light. A 2017 report by the National Counterterrorism Center titled “U.S. Homegrown Violent Extremist Recidivism Likely” said without elaboration that as of May 2016 Mr. Lindh “continued to advocate for global jihad and to write and translate violent extremist texts.”
A 2017 Federal Bureau of Prisons intelligence assessment, which included a photograph of Mr. Lindh with a shaven head and a bushy brown beard, said he had earlier made supportive statements about the Islamic State.
“From all I’m hearing inside of government, he is still as radical as he went in,” said Seamus Hughes, who is the deputy director of George Washington University’s program on extremism.
As conditions for Mr. Lindh’s release, Judge T.S. Ellis III of the United States District Court in Alexandria, Va., who handled Mr. Lindh’s 2002 trial and guilty plea, has imposed sweeping restrictions.
Mr. Lindh, who left California for Yemen in July 1998, two months before Google was founded, will be barred from going online or owning a web-capable device without prior permission of his probation officer. If he is eventually granted permission to own one, it would be on the condition of continuous monitoring of his online activities as well as using only English in his communications.
Mr. Lindh will also be barred from traveling internationally and getting a passport or any other kind of travel document. The travel ban thwarts any immediate possibility of his moving to Ireland, whose citizenship he acquired while in prison through his father’s mother, who was born in Donegal.
Other probation provisions require mental health counseling and prohibit Mr. Lindh from communicating “with any known extremist” or owning, watching or reading “material that reflects extremist or terroristic views.”
While Mr. Lindh’s presence in Afghanistan as a member of the Taliban during the 2001 invasion makes his case exceptional, some of the same issues raised in connection with his release apply to hundreds of other people who have been imprisoned in the United States for jihad-related terrorism crimes since 2001.
“In many ways, he’s a case study of a larger issue they have in government: They arrested hundreds of people since 2002 but there’s not a system in place to address these individuals,” Mr. Hughes said.
In all, 346 people have been charged and convicted of jihadist terrorism related crimes since the 2001 terrorist attacks, according to David Sterman, an analyst at New America who studies terrorism and violent extremism, citing a database maintained by the research organization. About one-fourth of those prisoners, 88, have been released, he said. About half should be released by the end of 2025, with 19 of them, including Mr. Lindh, on the path for release this year and next, Mr. Sterman said.
Mr. Hughes earlier worked on how to counter violent extremism in his capacity as a staff member at the National Counterterrorism Center, which was established in response to the 2001 terrorist attacks. So far, however, he said, the Bureau of Prisons, Justice Department, F.B.I. and court probation offices have yet to develop a single strategy for helping former jihadists re-enter society.
Because of the vacuum, he said, the best hope for Mr. Lindh is that his probation officer finds a Muslim former federal prisoner — someone who has conservative beliefs but is not radical — to help him navigate society.
“Ideally, you’d team him up with a mentor, somebody who perhaps had the same experiences as he may have had and came out the other side better of because of it,” Mr. Hughes said.
Johnny Spann, the father of the C.I.A. operative who was killed in Afghanistan, remains bitter about the Lindh case and said he is distrustful of the decision to let Mr. Lindh go. His son is buried at Arlington National Cemetery, about eight miles from the Alexandria courthouse where Mr. Lindh was charged.
“We’ve got a traitor that was given 20 years and I can’t do anything about it,” said Mr. Spann, a real estate dealer in Winfield, Ala. “He was given a 20-year sentence when it should’ve been life in prison.”
Mr. Spann’s son, who went by Mike, was killed at the start of an uprising by prisoners inside a mud-walled 19th-century fortress at Qala-i-Jangi in northern Afghanistan after he questioned Mr. Lindh, videotapes at the time showed. But even before Mr. Lindh’s guilty plea to two charges — to providing support to the Taliban and to carrying a rifle and grenade — the government offered no evidence that he participated in the revolt.
Mr. Lindh spent weeks in United States military custody after being captured. He was interrogated aboard a Navy assault ship, before being taken to the United States on Jan. 23, 2002 to face trial. By then, the Camp X-Ray detention site at Guantánamo Bay was crammed with 158 foreign prisoners. Most of those men, many of them captured in similar circumstances, would eventually be repatriated without charges while Mr. Lindh served his sentence in the United States.
It still enrages Mr. Spann that, a decade ago, Mr. Lindh’s father, Frank Lindh, said in a CBS interview that both their sons were “victims of the same circumstances.”
“Mike Spann was a person who believed in the rule of law,” the elder Mr. Spann said of his son, who joined the C.I.A. from the Marine Corps. “Mike Spann would’ve never agreed for a traitor to have got 20 years.”
Karen J. Greenberg focused on the Lindh case in her 2016 book, “Rogue Justice: The Making of the Security State.”
“He devoted his years in prison to becoming a student of Islamic texts,” said Ms. Greenberg, who is the director of the Center on National Security at Fordham University School of Law. “I think the best you can hope for him is that he finds a way to live a quiet life, along those lines, doing whatever it is he wants to peacefully do.”