Who should we believe?

The more people are victimised, the less account we take of their witness to torture and abuse

Abdullah crouched down until his knees just about touched the ground, nearly but not quite, and his head rested against a concrete wall. It was in this excruciating position that he was made to stay, blindfolded, for hours on end. "If I touched the floor with my knees," he explained, "they would come behind me and strike with their boots, or with rods."

Freed after four months in detention, Abdullah was describing his experience of a special US interrogation centre inside the Baghdad airport base. His worst moment, he said, was the electric shock treatment. Drawing a detailed diagram, Abdullah showed how crocodile clips had been attached to his genitals and then wires passed to a device which looked like a wind-up field telephone that generated a painful electric current.

"I could not believe they would treat a human being like this," said Abdullah, who was accused of involvement in the insurgency against US troops. He asked me not to print his full name as he still feared he might be rearrested. There is no appeal against such detention.

I interviewed Abdullah in Baghdad a couple of months ago, but I never published his account. How could I verify the terrible things he had said, in the face of total denials by US forces? How could I impugn their humanity? After all, Abdullah was a Sunni from el-Adhamiya, one of the city's quarters most hostile to the occupation, and perhaps he was lying.

Now I am inclined to believe what Abdullah told me. Like many Iraqis and Americans and Britons during this past week, I have crossed a sort of watershed in comprehension - in my willingness to believe the testimony of alleged victims of such abuse. This was apparent, too, in the official military inquiry into inmate abuse at the US-run Abu Ghraib, once Saddam Hussein's torture prison.

A few days ago, sitting in my hotel room in Basra, I was reading a report by Major General Antonio M Taguba dated 4 March, and originally marked as "secret/no foreign dissemination". The report outlines a shocking catalogue of torture that goes well beyond the photographs first glimpsed on the CBS show 60 Minutes. According to Taguba, various soldiers had confessed, among other things, to "forcing groups of male detainees to masturbate themselves while being photographed and videotaped . . . placing a dog chain or strap around a naked detainee's neck and having a female soldier pose for a picture". Further allegations included "breaking chemical lights and pouring the phosphoric liquid on detainees" and "sodomising a detainee with a chemical light and perhaps a broomstick".

Taguba said that "in the circumstances" he found these claims credible.

This phrase - "in the circumstances" - really struck me. It seemed Taguba, too, had crossed the watershed where he also could believe the words of the victim.

What happens, however, before such a conversion experience? How to tell fact from fiction in a war zone where every side requires powerful propaganda?

Driving around Amriya, another Sunni district in Baghdad, in January, I met residents who described what seemed like a systematic programme of arrests and detention by US forces as they searched for insurgents they believed might be lurking in some of the houses. One home I visited had been searched by troops with grenades. There was shrapnel in every wall and a hole in the middle of every floor: evidence of a grenade attack. I talked to the woman of the house. "All they had to do was ask and I would have let them in," she said. "Why did they have to destroy everything?" I wondered how much to believe: I knew her family did have links with the insurgents.

By a mosque, I came across a group of houses that had all been raided simultaneously one night, this time apparently by Polish special forces, working for the Americans, who were dropped by helicopter on to the buildings' roofs. A former chief of intelligence to Saddam had lived nearby and it seemed the US had decided to lift all young men and boys from the surrounding houses. Boys as young as 15 were held for three or four days and interrogated by soldiers. The evidence for their claims was on their wrists and ankles - most still had deep, festering gouges in their skin where plastic handcuffs had been left fastened for days.

The evidence of a policy of indiscriminate detention by US troops seemed clear. But then again, this was Amriya, a guerrilla stronghold. Who should believe the boys' words, or even sympathise with them because of their wounds?

Whether in Palestine/Israel, Bosnia, Rwanda or now Iraq, it is a terrible irony that the more a community is victimised, the less account we are likely to take of their witness. The victims have an axe to grind; they may be intent on revenge - and so they cannot be reliable. We reporters long for an "innocent" victim to give credibility to a story. Again, who to believe?

The great anger that has swept the world because of the US photographs of torture is a testament to the power of the visual image - but it is also a testament to its inherent weaknesses. Taguba's report shows that prisoner abuse was first confirmed last May; yet our anger was sparked only when, essentially, the abuse was all over. By raising the bar of what is considered acceptable "proof", we condemn ourselves to acting too late.

Whether the Daily Mirror's photo-graphs are authentic or not, they prove that the image as a medium for truth depends on the credibility of those who supplied it. Ultimately, it all comes down to human testimony, to staring someone in the eye and judging whether they are telling the truth - or whether you are.