New York - In 2008, when he joined the army, he was a bookish athlete from rugged Idaho with a passion for fencing. A year later, he was a captive of the Afghan Taliban. Today, he is on the way home, a free man at last.
But a new ordeal for Sergeant Bowe Bergdahl, aged 28, is just beginning.
Held alone for nearly five years, without any contact with fellow soldiers, Bergdahl likely suffered deep psychological scars that could take years to heal, possibly a lifetime, say experts who have studied prisoners held for long periods of time at war.
"You start feeling an attachment to your captors akin to that of your mother. It's primordial," said Frank Ochberg, a psychiatrist who has worked with such veterans since the Vietnam War. "You have to ask permission to eat, to move, to sleep, to crap."
Bergdahl's case was unusual from the outset.
Reuters interviews with his neighbours in Idaho and with US officials briefed on his disappearance in Afghanistan, along with US diplomatic cables and e-mail correspondence with his family, produce a portrait of a man disillusioned with war by the time he disappeared and whose bookish interests were at odds with the stereotype of the typical American soldier.
Home-schooled by his parents in rural Hailey, a speck of a town in mountainous central Idaho with just 8 000 inhabitants, Bergdahl was a loner who excelled at fencing and often disappeared on long hikes and bike rides, said Lee Ann Goddard Ferris, who lived next door to the family for 16 years.
"This is not unusual around here. Idaho breeds individuality and pioneer strength," she said.
A girlfriend recruited him to perform in local ballet productions. Bergdahl took a lot of teasing for that, said Sue Martin, owner of a Hailey coffee shop where he worked before joining the army. He also spent a lot of time by himself, she said, partly because home-schooling meant he didn't have a ready-made circle of friends.
He enlisted in the army in 2008, without telling his parents, drawn by recruiters' promises that he would be able to go overseas to help people, according to a 2010 Rolling Stone profile.
During time off from basic training in Georgia, when others in his unit hit the local strip clubs, Bergdahl went to a book store, and later surrounded himself with tomes on philosophy and Zen meditation, according to the Rolling Stone report.
Once deployed to Afghanistan, he appeared to become disillusioned about the US military mission there. In his final e-mail to his parents before his capture, he wrote, "I am ashamed to even be an American," Rolling Stone reported.
'Left on his own volition'
After he was captured on 30 June 2009, many believed he willingly walked away from his post. According to US diplomatic cables, Bergdahl's unit began searching for him that morning when he did not show up for roll call.
Later that day, US officials picked up radio communication between Taliban insurgents who said "an American soldier with a camera is looking for someone who speaks English," the cables said. Intelligence received three hours later indicated a US soldier had been captured.
"He left of his own volition," one US defence official said, declining to be identified because of the sensitivity of the subject. "But we have no idea of his motivation, or what was going through this young man's mind at the time."
Asked whether Bergdahl should be disciplined, US national security adviser Susan Rice told ABC News on Sunday: "Anybody who's been held in those conditions in captivity for five years has paid an extraordinary price".
Ochberg, the psychiatrist, said lingering questions of this kind could make Bergdahl's recovery more difficult. "He's going to have to contend with becoming a very public person in a very controversial atmosphere," he said.
Bergdahl's release was brokered by Qatar, and was in exchange for five Taliban militants being freed from the US prison at Guantanamo Bay, Cuba, and taken to the Gulf emirate.
Bergdahl was flown on Sunday to a US military hospital in Germany for a full physical and mental assessment, the first phase of an "reintegration process" with no "pre-determined" time limit, the US military said.
Rice, speaking to CNN, said that before the prisoner exchange was carried out on Saturday there had been indications that Bergdahl's health was "growing more fragile" and he had lost a good bit of weight.
Bergdahl's doctors will check him for post-traumatic stress disorder (PTSD), which has been diagnosed in tens of thousands of soldiers who have served in Iraq and Afghanistan.
But Bergdahl, say experts, is also at risk of "Stockholm syndrome," when captives become sympathetic toward their captors and adopt some of their beliefs, behaviours and even language due to dependence on them and a need to co-operate to survive.
The Taliban's proof-of-life recordings have fuelled speculation on the effects of his long captivity.
In one video released in 2010, Bergdahl said: "This war isn't worth the waste of human life that has cost both Afghanistan and the US. It's not worth the amount of lives that have been wasted in prisons, Guantanamo Bay, Bagram, all those places where we are keeping prisoners."
In a video dated 2013, Bergdahl has trouble putting together coherent English sentences. In an earlier one, he seemed to speak with a foreign accent.
Psychologists and others who have studied former prisoners of war say that during captivity they draw strength from fellow captives.
US Senator John McCain, who spent just over five years as a POW in North Vietnam after his plane was shot down in 1967, wrote in a 1973 account of his captivity that "the most important thing for survival is communication with someone ... the difference between being able to resist and not being able to resist."
However, Bergdahl had no one to share his ordeal.
Martin, the coffee shop owner who worked with Bergdahl before he joined the army, described him as "very intelligent" and speculated that this will serve him well as he tries to recover. "He's introspective and very respectful of people," she said. "He's a thinker."
The soldier's father, Bob Bergdahl, made clear that the family was moving very gingerly toward re-establishing contact and had not yet even talked to him by phone.
"That's because Bowe has been gone so long that it's going to be very difficult for him to come back," he told reporters in Idaho.
"It is like a diver going deep on a dive and he has to stage back up through recompression to get the nitrogen bubbles out of the system. If he comes up too fast, it could kill him."
Research suggests there is good reason for caution in the case of Bergdahl, who a defence official says will later be transferred to a medical facility in San Antonio, Texas.
Those who develop post-traumatic stress "wake up in the middle of the night and have flashbacks so detailed they can smell the body odour of their captors," Ochberg said