The revelation of physical, psychological and sexual abuse of Iraqi prisoners by serving US military personnel in Iraq's Abu Ghraib prison was a defining moment for the US-led occupation of Iraq. This was when the entire Arab world shuddered in revulsion at the bestial activities of US soldiers, and the moral standing of the United States was wrecked.

The crisis was all the worse because no senior officer or political official took any responsibility for what US soldiers had been doing. Specialist Charles Garner was released this week after serving only six years of his 10-year sentence for offences including stacking naked prisoners into a pyramid, knocking one out with a head punch and ordering prisoners to masturbate while US soldiers took pictures. Eleven other US soldiers were found guilty in US military courts of charges ranging from dereliction of duty to aggravated assault.

But despite the horrors being perpetrated in the prisons, the officer in charge of all US-managed prisons in Iraq, Brigadier General Janis Karpinski, was only reprimanded and then demoted in 2005. Amazingly, Karpinski managed to deny all knowledge of the abuses, and claimed that the abuse was in fact interrogations which were authorised by her superiors.

No one has answered these questions, and to this day no senior US military officer has taken responsibility for what was going on in the US-managed prisons. Then secretary of defence was Donald Rumsfeld, and the Chairman of the Joint Chiefs of Staff was General Richard Myers. Neither took any blame for the crimes, and their careers continued as though nothing wrong had happened in Abu Ghraib's cells.

The Iraqi people and the US people deserve better. Both Iraqis and Americans need to know that the US military wants to operate to the highest standards possible, and they cannot comprehend this without proper responsibility being taken for its failings.