The story of 20-year-old John Walker Lindh, known as the "American Taleban", has shocked America.
Captured by US forces in Afghanistan with a group of Taleban and al-Qaeda fighters who survived the bloody Mazar-e-Sharif revolt, Mr Walker now faces charges of conspiring to kill US nationals and aiding Osama Bin Laden's al-Qaeda network.
This is American justice?
Chodon Mia, Bangladesh
The question being asked is: What led a "bright and quiet" middle-class child from California to fight against his fellow Americans in a far-off country?
His parents believe he was brainwashed, and his friends say there were no signs that he planned to become a jihadi, or holy warrior, as he described himself to a Newsweek reporter.
"This is a kid who would freeze from fear... totally not streetwise," his mother Marilyn Walker said.
A politically motivated sentence handed down to satisfy public craving
Dean Moriarty, UK
Named after the former Beatle John Lennon, John Walker Lindh was born in Washington DC in February 1981.
His father Frank Lindh, an Irish Catholic, worked at the US Justice Department by day and studied law by night, until he graduated with honours and joined a law firm.
A neighbour quoted by the Washington Post described the Lindhs as a "Birkenstock family... very earnest, very nice, very intellectual."
When John was 10, the family moved to Marin County, one of California's wealthiest counties and often caricaturised as "hot-tub haven".
In California he attended what has been described as an elite alternative high school, where students were allowed to shape their own studies.
His teachers say he was a good student. And the US media have portrayed him as an average, if quiet teenager, with a basketball hoop in the drive and an interest in hip hop music.
What really hearts is that he is been handed over to Americans by so-called muslims
At some point in his mid teens, John Walker is said to have stopped visiting hip hop internet sites and to have begun exploring Islamic ones instead.
His parents believe his interest in Islam may have been sparked by the autobiography of Malcolm X, which he read when he was 16.
That same year he told his parents he wanted to convert to Islam and he began attending a mosque.
He studied the Koran, adopted the name Sulayman and started wearing a long white robe and a turban. He also got rid of his collections of hip hop and rap CDs.
In 1998, when his parents were splitting up, John Walker asked them for money to go to Yemen. He said it was the best country to learn the "pure" dialect of Arabic used in the Koran.
After a year in Yemen, he was back in California, studying at a San Francisco mosque.
But his friends there say he seemed restless and no longer felt comfortable in the US.
He returned to Yemen in February 2000, a few days before his 19th birthday. It was the last time his parents saw him.
His enlistment with the Taleban does not constitute treason nor a reason for punishment
M Shariff, Asia-Pacific
In retrospect, Frank Lindh says the signs that his son was "changing" came in an exchange of e-mails after the October 2000 attack on the USS Cole which was docked in Yemen.
Mr Lindh recalls that John Walker suggested that by docking its ship there, the US had committed an act of war.
"It was clear he had developed a different point of view," Mr Lindh told Newsweek magazine.
John Walker then told his parents he would enrol at a madrassa (a religious school) in the village of Bannu, in Pakistan's Northwest Frontier province.
His teacher, Mufti Mohammad Iltimas said he was a model student. In his conversations with him, he said, John Walker talked about feeling alone in the US and "comfortable and at home" at the madrassa.
However, not even at the madrassa did he seem to like socialising, reportedly saying it was a waste of time.
Last May, John Walker sent an e-mail to his parents saying he might travel to "someplace cooler" for the summer and asked his father for money.
No mention of Afghanistan was made, Mr Lindh said.
After that, the first news they had of their son came eight months later when they saw him on television in the hands of US troops. He gave his name as Abdul Hamid.
According to the affidavit filed against him, Mr Walker told US interrogators that in May he had joined a paramilitary training camp run by a Kashmiri militant group in Pakistan.
He then chose to join the Taleban.
He told a Newsweek reporter that he entered Afghanistan "to help the Islamic government... because the Taleban are the only government that actually provides Islamic law."
There he was then sent for seven weeks to an al-Qaeda training camp, where he is said to have met Osama Bin Laden who thanked him for taking part in the jihad.
The "American Taleban", John Walker Lindh, has been sentenced to 20 years imprisonment by an American court for fighting the Taleban in Afghanistan.
Lindh had faced one charge of collaborating with the Taleban and another of carrying an assault rifle and grenades while fighting with the extremist regime.
The 21-year-old from California had pleaded guilty in a deal agreed with prosecutors to lighten his sentence in return for his co-operation in the investigation into al-Qaeda.
Asked by a reporter about his experience in Afghanistan, he replied: "It's exactly what I thought it would be."
Did he think he had been fighting on the right side?
Did you think that you were fighting for the right cause ?
"Definately " was the answer
Speaking to one of the reporters
"Definitely," was the answer.