Martha Gellhorn, the redoubtable journalist who has covered practically every conflict since the Spanish Civil War, believes that: "If you can't change it, at least record it." But it seems that much of the British media is pre-occupied with protecting its audience from brutish truth, rather than exposing it.
"The Grave" contains hideous, horrifying scenes, because the story it tells is appalling. In November 1991, the Yugoslav National Army, which had besieged the rebellious Croatian city of Vukovar, finally broke through. The town's exhausted defenders surrendered, and Major Veselin Sljivancanin and his victorious Serb troops moved into the hospital.
They began to separate men - mostly wounded patients, medical staff and a few elderly civilians - from the women and children. Grainy video footage from the time shows Serb troops lining up men lying on stretchers for "evacuation". The women and children were bussed out; they never saw their men again.
It did not take long for the story to trickle out, though. A bus trip to a warehouse in Ovcara, two miles away, where the men were badly beaten, and then another short hop to a field where they were lined up, shot and buried in a mass grave.
In the spring of 1996, the International War Crimes Tribunal in The Hague delivered indictments for the Vukovar massacre against Sljivancanin and two colleagues, and last summer, forensic experts exhumed the mass grave at Ovcara, uncovering 198 men and two women.
Their work forms the subject of the Channel Four film made by Belinda Giles, producer and director, and Paulette Farsides, a journalist who was taken on a guided tour of the fallen city by the Serbs shortly after their victims were taken away to be shot.
Ms Farsides spent months persuading the Tribunal, which is very sensitive to the presence of the media for fear of prejudicing future trials, to grant access to her crew. The result is horrifying, shocking, offensive - almost as offensive as the crime itself.
Here I must declare an interest: the film-makers are friends of mine (we met covering the war in Bosnia), so I knew they were making this film and I was keen, when they telephoned, to try to help publicise their film. Channel Four found it hard to drum up media interest - not only is the world bored of the Balkans but the story is thought by some editors to be too gruesome to write about.
"The main thing was it being on a very difficult, dark subject: lots of newspapers didn't want to touch it," said Paul Smith, a C4 press officer. "Newspapers don't want to have harrowing images on their pages, which I think is very different from a couple of years ago. There's also this belief that we don't want to read about that, we don't want to know that, which is patently not true. People want to know what went on."
Gilles Peress, a photo-journalist of great renown, had a similar experience trying to sell his Ovcara pictures to British magazines - none have agreed to publish them, although the photos have appeared in France, Italy, Germany and the US.
"We would run them on the news pages, " says Andrew Marr, editor of the Independent. "If you are revealing some crime that is genuinely shocking to your readers, then you have to be prepared to show your readers what actually happened."
I watched "The Grave" in the office, which is probably why I remained relatively dry-eyed - at home I would have shed tears, not of sorrow, but of anger. And as I watched what must be some of the most grotesque pictures ever shown on British television, I wondered whether I was more or less sensitive to them than the average viewer - I have witnessed such scenes in real life.
But you probably haven't seen anything like this (except in a horror movie), for the media in the Anglo-Saxon world seems to shield its audience from the consequences of the worst human behaviour.
And sometimes I can see why. There is no need to show the bodies of Thomas Hamilton's Dunblane victims: we all agree that mad gunmen should not be allowed to murder children. But the wars in the former Yugoslavia, a prime British tourist destination, were fought at least in part with the tacit approval of our government.
So why did Channel Four decide to go the whole way and let Ms Giles and Ms Farsides tell the story as it happened? Peter Moore, the senior commissioning editor for documentaries had no hesitation in backing an uncensored version of the dig, gruesome as the pictures are.
"You do need to have a permanent, contemporary record so that those who will try, cannot deny," he says. "People always come out and try to contest the truth, so these epic documentaries ... dare others to deny that this is what happened."
Or as Belinda Giles argues, "I couldn't watch The Dying Rooms, because it made me too upset, but that's no reason not to show the film."
Martin Bell MP, the distinguished television correspondent, fought many battles with the BBC over their refusal to air pictures from Bosnia that he felt were needed to tell the story. "The sanitisers prevailed at the BBC from, I would say 1993 onwards, and only now is a call for more realism being heeded - but moderately," he says.
"Although [the pictures] are macabre, and some would say they serve no useful purpose in prevention, they do, and that's all I can say," Mr Moore continues. "The world has a short memory, and we are all guilty of not doing enough."
But that is all in the past, said one colleague, so why upset yourself by watching such images? "Would you make the same argument about Auschwitz and Buchenwald?" asked Martin Bell. "My goodness, it is upsetting, it should be upsetting, but that's not a reason to avert our gaze. We have to know what happened and we should know what happened."
As they said in Europe 50 years ago, lest we forget. And by the way, Veselin Sljivancanin was promoted after the fall of Vukovar and works at Belgrade's military academy. There is no danger that he will be arrestedn
The Grave, Channel 4 tomorrow at 9pm