By Paul Reynolds
World affairs correspondent, BBC News website
The acquittal of a US army colonel on charges relating to the abuse of prisoners at Abu Ghraib means no officers have been found criminally guilty.
The episode stained the reputation of the US military and may well have acted as a recruiting agent for insurgents.
Ten junior soldiers have been convicted over the Abu Ghraib abuse (AP Photo/Courtesy of The New Yorker)
The officer, Lt-Col Steven Jordan, was found not guilty by a military jury of failing to train and supervise the soldiers under his authority at Abu Ghraib.
Instead he was convicted of breaking an order not to discuss the case. He was reprimanded.
The lack of convictions among the senior ranks leaves doubt as to whether the abuse was part of a wider policy of condoning or even encouraging the breaking of prisoners' morale in advance of interrogation.
Two officers were subject to disciplinary punishments.
Col Thomas Pappas, the senior military intelligence officer at the prison, was reprimanded and had pay deducted for dereliction of duty. This included allowing dogs to be present at interrogations.
Brig-Gen Janis Karpinski, the officer in charge of Abu Ghraib and other prisons in Iraq, was reduced in rank to colonel for dereliction of duty.
Policy of abuse?
The burden of criminal guilt has fallen on the junior ranks, 10 of whom have been convicted.
Some of them appear in the infamous photographs of prisoners being humiliated and beaten, displaying obvious satisfaction at the acts.
Spc Charles Graner and his then girlfriend Lynndie England, seen grinning in several of the photos, got 10 and three years respectively.
Sgt Ivan Frederick, the most senior of the soldiers convicted, was given eight years. Another of the grinning guards, Sabrina Harman, was sentenced to six months.
Harman was among those who claimed that the abuse was policy. She told the Washington Post newspaper in 2004 that the military police (MP) had to break the prisoners down for questioning.
"The job of the MP was to keep them awake, make it hell so they would talk," she said. She blamed military intelligence officers and civilian contractors who conducted the actual interrogations.
However, Sgt Frederick gave a different account and implied to US television channel CBS, which helped break the story, that there was no direction.
"We had no support, no training whatsoever. And I kept asking my chain of command for certain things... like rules and regulations - it just wasn't happening."
And Joe Darby, the soldier who blew the whistle by giving to investigators a CD of the photos presented to him by Charles Graner, also denied it was organised from on high.
In a long interview with Gentleman's Quarterly, he said: "Everybody thinks there was an order from high up, or that somebody in command must have known.
"Everybody is wrong. Nobody in command knew about the abuse, because nobody in command cared enough to find out. That was the real problem."
But suspicions linger.
The report into the Abu Ghraib scandal by Maj Gen Antonio Taguba pointed out Maj-Gen Geoffrey Miller, the commanding officer at Guantanamo Bay, had written a report on Abu Ghraib in August 2003.
The report stated: "It is essential that the guard force be actively engaged in setting the conditions for successful exploitation of the internees."
This phrase is taken to mean more or less what Sabrina Harman expressed - the prisoners had to be broken down to make them amenable to interrogation.
Gen Miller shed no light on this during the inquiries.
He invoked his right to silence when Col Pappas accused him of recommending that dogs be used to frighten prisoners.
Dogs are seen in several of the Abu Ghraib photographs.
Gen Taguba did not find that there was a deliberate policy of abuse ordered from above.
He reported only that "several US army solders have committed egregious acts and grave breaches of
international law" and that "key senior leaders... failed to comply with established regulations, policies, and command directives in preventing detainee abuses at Abu Ghraib".
The chain of responsibility was also investigated and found not to exist by a panel headed by former Defence Secretary James Schlesinger.
"There was sadism that was certainly not authorised," he reported. "It was kind of like 'Animal House' on the night shift."
Not that it mattered much in the court of world opinion that the military establishment did not find criminal fault with the senior officers - Abu Ghraib damaged the whole US military and reflected badly on the occupation of Iraq.
One of those interviewed for the original CBS report was former Marine Lt-Col Bill Cowan.
He said: "We went into Iraq to stop things like this from happening, and indeed, here they are happening under our tutelage."