When prisoners were brought to Saddam Hussein's intelligence service for interrogation, their torturers often videotaped the torment.
In the years after his downfall, I lectured around the world on the illegality and the immorality and the outrageous civilian slaughter of the invasion of Iraq by George W Bush and Lord Blair of Kut al-Amara (now, of course, Lord Blair of Isfahan).
But I also carried with me extracts from those obscene videos - just in case the war's detractors forgot just what an iniquitous man Saddam actually was.
To spare the sensitivities of audiences, I cut hours of video down to a raw and terrifying minute and a half in which prisoners in underpants were whipped with wire by uniformed guards, made to crawl in sewers and were eventually piled in a bloody heap of the semi-dead.
Blood was the colour.
The only sounds were of the guards' abuse and the screaming and pleading of the captives. The videos were originally shot to shame the prisoners, but also, I suspect, for the sense of domination it gave the torturers.
The Abu Ghraib pictures - US torturers taking over the role of the Iraqi thugs in the very same prison in which many of the earlier Saddam videos were shot - had perhaps the same purpose. Lynndie England saw nothing particularly wrong with them. That was what Iraq was like, wasn't it? And we must forget, of course, that other American pictures from Abu Ghraib, which Obama the Good has decided we must not see, show the rape of Iraqi women and boys.
Janina Struk's new book on soldiers' private pictures of war, which I wrote about last week, contains some paragraphs about the new military art of filming, editing and producing war by video, the soldiers' very own version of Hollywood, in which real soldiers play themselves in real life and real Iraqis are cut down and killed in front of the camera.
If the Vietnam-era US army could take photos of its own atrocities, American soldiers in Iraq have gone a step further. In some videos Struk watched, pounding rock music accompanies images of US soldiers apparently firing at random Iraqis in Fallujah. But this isn't the only location for filmed atrocities.
"One," writes Struk, "explicitly entitled 'Troops Throw Flashbang Grenade at Iraqi Farmer and His Sheep' shows precisely what its title suggests. A grenade is thrown from a moving vehicle at an elderly shepherd tending his flock of sheep grazing by the side of the road. It hits the target and explodes. There is laughter and the film ends."
The insurgents of Iraq have used the same system, albeit for more grimly doctrinal reasons. The videotaping of the mass shooting of captured police officers north of Baghdad (a colour version of 1942 Nazi images from the Ukraine and Belarus) and the beheading-execution of hostages was intended to dissuade Iraqis from collaborating, and of frightening the West into retreating from Iraq.
And who of us has clean hands? In 1992-93, I was a reporter on a three-part film series called From Beirut to Bosnia, which showed terrible scenes of suffering from hospitals in Beirut, Cairo, Sarajevo and Gaza. In Gaza City, a Palestinian Hamas member was shot in the head by an Israeli soldier and we filmed him - with his family's permission - as doctors tried to prevent him from swallowing his tongue as they operated.
I don't know if he could see us or hear us. But he died as we filmed him. And, if conscious, the last thing he saw and heard on earth was the black and white clapperboard snapping shut in front of his face to the words: "Three and one on the end!"