Leading article: The worst instincts of the bully

The forgotten protagonist of the WikiLeaks story spoke in a US military court on Friday to confirm that he had read the charges against him. "Yes, sir," said Bradley Manning. The young soldier – yesterday was his 24th birthday – is not exactly a butterfly, but he is certainly on a wheel.

In fact, he has been crushed between two opposing cogs. On the one hand, the US Department of Defense accuses him of high treachery against American national security, leaking a quarter of a million diplomatic cables. On the other, WikiLeaks supporters celebrate him as a hero, in a fight against authority and secrecy.

Both of these two world-views overlook the vulnerable person at the story's centre. On the WikiLeaks side, far too much attention has been sought by and devoted to Julian Assange, who was merely the publicist for material passed to a group with which he has now fallen out – as he often seems to do with his co-workers.

On the Pentagon side, Pte Manning has been treated as a non-person. Partly, this may be because the Defense Department realises at some level that it failed in its duty of care to him. Since his arrest, it has emerged that his superiors had intended to discharge him, because he seemed unstable and a risk to himself and others. Yet the army changed its mind – possibly because of a shortage of computer intelligence analysts in Iraq – and sent him to east Baghdad anyway.

There, morale was low and security even lower, with login details for the Secret Internet Protocol Router Network (SIPRNet) written on notes stuck to the side of computer screens. A month after Pte Manning first contacted Wikileaks, an army psychologist found that he was "potentially dangerous to himself and others", according to the document prepared by his legal defence team that we report today. His gun was disabled and later he was disciplined for punching a female officer. Yet still he was allowed access to secret information.

Since Pte Manning's arrest, the US military has defaulted to its assumption that national security trumps all considerations of humanity – a position that has done so much damage to America's standing in the world since the Second World War. Pte Manning has been held, in effect, in solitary confinement, was at one point deprived of bedclothes, and is woken repeatedly "for his safety and security".

His treatment prompted P J Crowley, the official spokesman at the State Department, to say: "What is being done to Bradley Manning is ridiculous and counterproductive and stupid." Mr Crowley resigned, but he achieved at least one thing, forcing Barack Obama to say that Pentagon officials "assure me" that the terms of Pte Manning's confinement were "appropriate".

Such weasel words emphasise the bad part of the good-in-parts attempt by President Obama to recover some of the moral ground lost by his predecessor. Unfortunately, Guantanamo, which Mr Obama promised to close, has now been open for 10 years, and still holds one British resident, Shaker Aamer, in legal limbo.

The Obama administration's failure to wash away the sins of George Bush, Dick Cheney and Donald Rumsfeld is, incidentally, a reminder to us of the importance of, for example, the Gibson inquiry in atoning for the British record of collusion with torture in the Bush-Blair years.

The Bradley Manning story, some of which was reported in The Guardian in May, but which has not attracted sufficient attention, is one of the mighty American superpower overreacting to its failure to spot the security risks of a troubled young man in a military base ruled by tedium. It reflects its own mortification over the leaks that resulted.

This newspaper does not believe that it was right to leak confidential documents indiscriminately, but the fears expressed by Hillary Clinton, US Secretary of State, that the security breach would put lives at risk, seem to have been exaggerated. In fact, its main effect has been to embarrass some US allies, such as the Saudi princes who privately urged military action against Iran.

The Pentagon has reacted to its humiliation with the worst instinct of the bully, taking a vindictive attitude towards a scapegoat. If Pte Manning is guilty as charged, he did something wrong, but it is the US authorities who must take responsibility for the intelligence disaster.