Srebrenica: Four Years On: 5,000 walked to their deaths in three days and all Major protested was his innocence

ONCE UPON a time, it was just another sleepy forgotten town in the green hills of Bosnia. Now, Srebrenica - "place of silver", known to the Romans as Argentaria - stands as the ultimate symbol of the horror that Slobodan Milosevic has unleashed in the Balkans in the past decade.

Previously unpublished letters from the then prime minister, John Major, attack the "disgraceful" suggestion that Britain did too little for the thousands of Muslims murdered at Srebrenica. But new evidence makes it clear that the charge was justified. A senior US diplomat has revealed that the preservation of "safe areas" in Bosnia was deemed to be "not compatible" with a solution to the Bosnian war.

The killings at Srebrenica in July 1995 serve as a reminder that, as Europe enters the twenty-first century, no nightmare is too horrifying to be real. Since 1945 politicians have repeatedly chanted about "learning the lessons of history". "Never again", the history books told us. In reality, as Bosnia showed, none of the lessons had truly been learnt.

The world has rightly been shocked by the killings in Kosovo, where maybe 5,000 Albanians died in the whole province in a few months. At Srebrenica more than 7,000 were murdered - mostly shot in the head before being dumped in mass graves - in just a few days in July 1995. Even by the lethal standards set by Milosevic's placemen, it is a daunting record. A film to be broadcast on BBC2 tonight exposes with searing clarity the horror of Srebrenica.

It exposes, too, the responsibility of Western powers that refused to help, repeatedly turning their faces away from a reality that stared them in the face. Tonight's programme shows us events unfolding before our eyes, as recorded by the Serbs themselves. "A catastrophe witnessed by camcorder," in the words of film-maker Leslie Woodhead.

A Bosnian Muslim is asked by an unseen questioner: "Are you afraid?" He looks into the camera with the certainty of approaching death, and asks quietly: "How could I not be afraid?" The Serb cameraman never seems to leave Mladic's side; the pictures, intended to provide heroic propaganda, bear witness to preparations for genocide. Ratko Mladic, the Bosnian Serb commander, declares: "The time has come to take revenge on the Muslims." At the same time, he doles out food and assures terrified and disbelieving civilians that nobody will die. "Not your husbands, not your brothers, not your neighbours." (As one Serb told The Independent at the time: "Mladic was taking meat paste from a box I was holding and was distributing it to the children, saying: `Take it, take it.' Why, he even patted some of those kids on the head. This is the sign of a truly great warrior. Only the Serbs have this capacity of forgiveness." )

We see the division of the civilians, where the men (defined as from age 11 to 77) are separated from the women and young children. Their eyes turn to the camera, freeze-framed before death. Zumra Shekhomerovic torments herself because of her failure to do something - anything - to fight for her husband as he was separated from her, after placing his trembling hand on her shoulder. "I regret so much that I didn't scream or shout for help. Maybe it would be easier to live now. I just left silently. My tears were flowing like a river - and still do today."

A standard get-out clause for politicians is to claim that things only become clear in retrospect. "20-20 vision is easy with hindsight, isn't it?", they like to say. In reality, no hindsight was needed. Every Muslim in Bosnia understood what the Serb forces were capable of; only the Western governments refused to see it.

Britain played a key role in blocking UN military action that might have stopped the Serbs. Politicians sneered at the "naivete" of anybody who suggested a more robust approach. And yet it was impossible to spend any time in the Balkans and fail to understand. The pattern of threats was clear from the start. A snapshot remains vivid in the memory from the earliest days of the Bosnian war, three years before Srebrenica.

I was driving a Muslim woman and two children out of Bosnia, at the request of a Sarajevo friend. At a Serb checkpoint on a mountain road, the gunman questioned my passengers, with a sadistic enjoyment that would have seemed appropriate for an SS man questioning a Jew in 1939. The woman and children were terrified of the gunman's absolute power; he relished their fear. We all knew that if he and his colleagues decided to bundle my passengers out of the car (kidnap, kill, whatever) I could do nothing. I, with my cosy Dieu-et-mon-droit passport, would have bleated ineffectually, and eventually driven off - with a gun at my head, if my complaints were too prolonged and foolhardy. As later became clear on a grand scale, good intentions count for nothing unless they are backed up by some kind of force. All that was needed was commonsense, and the ability to keep one's eyes and mind open, to understand that simple truth.

In May 1995 Paddy Ashdown - who was outspoken on the need for action - wrote to Mr Major to ask for undertakings regarding the safety of Muslims in the besieged enclave of Srebrenica. Mr Major replied: "Britain's concern for the safety of civilians in the eastern enclaves is well known." In reality, the concern was limited, at best. Later that year, The Independent revealed that the UN - with the encouragement of London - had, in effect, given up on Srebrenica back in May.

General Bernard Janvier, commander of UN forces in Bosnia, was blunt with his advice: "We must be pragmatic - but above all honest with the men whose security is our hands: without lightning rods, stay out of the storm!" In other words, give up on the "safe area". Britain played a key role in formulating this policy.

When Mr Ashdown wrote again to ministers, regarding Robert Block's reports in The Independent, there was an indignant response. The letters from Malcolm Rifkind, then foreign secretary, and from Mr Major have been seen by The Independent; they are evasive and threatening by turns.

Mr Rifkind complained of "absurd allegations"; Mr Major complained of a "disgraceful" line of questioning, and demanded that Mr Ashdown apologise. "Our forces have worked valiantly to bring humanitarian relief to the people of Bosnia."

This was true, as far as it went. But the aggressive bluster from Downing Street sought to conceal the fact that Britain had indeed been ready to let Bosnia be trampled - so that the "humanitarian relief" would not be put at risk. The British forces in Bosnia were hamstrung because, under their political mandate, they could not take tough action that was clearly needed.

The Dutch in Srebrenica faced similar difficulties. The Dutch battalion was supposed to protect the "safe enclave" of Srebrenica, but could not do so alone. When it became clear that the Serbs were moving in on Srebrenica, the Dutch commander, Colonel Ton Karremans, asked UN headquarters for Serb positions to be bombed. His requests were denied. One request was turned down because it had been submitted on the wrong form.

The Dutch have been criticised - and have criticised themselves - for their manifest failure to protect the Muslims of Srebrenica. Devastating testimony in tonight's film comes from Hasan Nuhanovic, a Bosnian interpreter who was forced to let his father, mother and sister be driven out of the relative safety of the Dutch compound near Srebrenica; they were never seen again. He still reproaches himself. "For some reason at such moments, you have no brain, you are so obedient that you just do what they tell you. Nobody even complained when they walked towards the gate, knowing that they were probably going to die." There are sickening scenes where Dutch soldiers celebrated with a literal knees-up - waving their cans of Heineken in the air as they danced - after they came out of Srebrenica to the safety of UN headquarters in Zagreb.

None the less, the buck did not stop with the Dutch. It stopped with the Western governments - especially the UK, which was determined not to let the heat be turned up high. The UN itself admitted last week that the insufficient military response resulted from "an inability to recognise the scope of the evil confronting us".

The ultimate criminals were, of course, the Serb and the Bosnian Serb leadership. For the moment, Serbs bury themselves in denial about crimes that their compatriots have committed. Say the word "Srebrenica" to the average Serb today, and you will hear a long and fluent lecture about Western propaganda and Muslim lies. That must eventually change. The message of this film may one day be heard and understood in Serbia, too. In Germany, denial of the Holocaust - the Auschwitzluge - is a crime. In Serbia, with luck, the "Srebrenica lie" might also one day be a crime; but that day is a long way off, even if Slobodan Milosevic steps down tomorrow.

With its "pragmatism", Britain played a key role in allowing the nightmare of Srebrenica to take place. Understanding that failure can help ensure that "never again" is no longer just a hollow cry.

`A Cry from the Grave', written and directed by Leslie Woodhead, BBC2, 10.25pm