Bradley Manning spent his 23rd birthday last Friday alone in a tiny, bare prison cell, without a pillow or sheets on his bed, in weak health and wracked with anxiety at the prospect of a prison sentence of 52 years.
The young American soldier has faded into the background as international ructions continue over the hundreds of thousands of pieces of classified material from the US government that he is alleged to have supplied to WikiLeaks.
Now the fate of the whistleblowing website's founder, Julian Assange, lies in the hands of the former US Army intelligence analyst.
US sources have revealed that prosecutors are awaiting a decision from the US Attorney-General, Eric Holder, on what form of plea-bargain they should offer to Private First Class Manning in return for him incriminating Mr Assange as a fellow conspirator in disseminating the classified information.
Officials at the US Justice Department - who are under acute pressure to prosecute - privately acknowledge that a conviction against Mr Assange would be extremely difficult if he was simply the passive recipient of the material disseminated by PFC Manning.
Any evidence that he had actively facilitated the leak, however, would make extradition and a successful case much more feasible.
Manning's friends stress that, so far, he has refused to co-operate with the prosecutors.
However, they also say that, after seven months of solitary confinement at the Quantico Marine Base in Virginia, he is in an increasingly fragile condition.
He is charged with leaking a US military video showing a 2007 attack by Apache helicopters that killed 17 people in Iraq - including two Reuters employees.
Speaking after his release on bail of £240,000 as he fights the extradition request from Sweden for alleged sexual offences, Mr Assange insisted: "I had never heard of the name Bradley Manning before it was published in the press. WikiLeaks technology [was] designed from the very beginning to make sure that we never know the identities or names of people submitting us material."
But Adrian Lamo, a former hacker who had been in contact with Manning and eventually turned him in to the US government, has told the FBI that Mr Assange had given the young soldier an encrypted internet conferencing service as he was downloading government files and a dedicated server for uploading them to WikiLeaks.
Mr Lamo claims that Manning had "bragged" about this to him. In one e-mail, now in the possession of the US Justice Department, the soldier allegedly wrote: "I can't believe what I'm confessing to you . . . I'm a source, not quite a volunteer, I mean, I'm a high-profile source . . . and I've developed a relationship with Assange."
David House, a computer programmer who visits Manning in prison, said: "I have noticed a steady decline in his mental and physical wellbeing.
His prolonged confinement in a solitary holding cell is unquestionably taking its toll on his intellect."
The authorities had initially stated Manning was being kept in solitary confinement for his own safety. Friends like Mr House now believe it is being done to put pressure on him.
Manning downloaded the files he is accused of subsequently sending to WikiLeaks while serving with Operation Station Hammer in Iraq.
He put the classified material on to a Lady Gaga CD, with the music wiped out.
He described lax security where "everyone just sat at their workstations . . . watching music videos, car-chases, buildings exploding, weak servers, weak logging, weak physical security, weak counter- intelligence, inattentive signal analysis . . . a perfect storm."
His e-mails also reveal that he was emotionally fraught after breaking up from a gay relationship.
He wrote to Mr Lamo: "I'm a wreck. I just wanted to be nice and live a normal life . . . but events kept forcing me to figure out ways to survive. I've been so isolated so long . . . I'm self- medicating like crazy when I'm not toiling in the supply office.''
Robert Feldman, a US lawyer specialising in security issues, said: "We kind of have a picture of a troubled young man with obvious problems.
"Yet no one in the army system picked this up and he was allowed access to secret information. And we also see security around the place was pretty loose. So a trial would be embarrassing to the DoD [Department of Defence] whatever happens.
"But if they can prove complicity on the part of Assange in organising the leaks, then a picture can be drawn of an Assange, an older man, who manipulated an emotionally disturbed younger man. But to do this, they obviously need evidence of complicity."
Mr Assange said his US lawyers told him that a grand jury has been secretly empanelled in Alexandria.
A number of hackers have also claimed they have been offered money in return for evidence of WikiLeaks's wrongdoing.