Things sometimes go well. The arrest of Ratko Mladic, though long overdue and cynically co-ordinated with Serbia's overtures to the EU, is truly to be welcomed. Rather than a corpse lying in a compound, we have the living individual who ordered the largest mass murder in Europe since the Second World War and now he will stand in court to be confronted with the unimaginable pain that his actions caused in Sarajevo and the Muslim enclave called Silver City – Srebrenica.

Whether justice can really be achieved after such crimes is another matter, but this course is infinitely preferable to the operation carried out against Osama bin Laden at Abbottabad a few weeks ago. However rotten Mladic seems and however dreadful his crimes, with his extradition to the International Criminal Tribunal in the Hague we assert values that are the very opposite of the darkness that descended in the break-up of Yugoslavia. No retribution can be devised to match what he did, but there will be a modest gain for civilisation from his arrival in the Hague, just as there was when John Demjanjuk was sentenced in Germany two weeks ago – 58 years after he helped kill thousands of Jews in the gas chambers of Sobibor.

The massacre of 8,500 Muslims at Srebrenica may have been largely forgotten until last week, but the effects of the events between 10 July and 13 July 1995 are still with us today. Both the rise of Islamism and revival of the doctrine of liberal interventionism – what Lord Palmerston described as England's real policy of championing justice and right – can in part be attributed to the shock of what happened in those three days under the noses of the United Nations, a prevaricating French general, a laissez-faire British government and a force of 700 Unprofor soldiers from Holland who handed the population of Srebrenica to the Serbs after their commander drank plum brandy with Mladic.

Bosnia was a reporters' war: there was no embedding of journalists, there were no definite battle lines, and over the two-and-a-half years of hostilities between Serbs, Muslims and Croats, it produced stories of unbelievable cruelty and heartbreak. Among the many courageous acts by journalists was one by David Rohde, then of the Christian Science Monitor, now of the New York Times. A month after the killings at Srebrenica, he hired a car, went into the countryside not far from the town and found new bullet holes along the walls of farm buildings, evidence of mass graves and such clues among the dead as recently dated receipts from Srebrenica. On a later trip into Serb territory, he was imprisoned by the Bosnian Serbs after finding further evidence at four sites.

I don't claim that Mladic's massacre would have remained hidden without Rohde's reporting – there were plenty of radio intercepts and satellite pictures to suggest what had happened – but the fact that he demonstrated so quickly that 8,500 people had not fled across 43 miles of forest and open countryside towards the Bosnian town of Tuzla, as the Bosnian Serbs claimed, cannot be underestimated. The massacre was so recent – people could remember what they were doing that week in July – and it had occurred in broad daylight on European soil.

What was even more astonishing was that the UN did not seem to have any knowledge of it; still less did the UN officials and soldiers who were meant to be protecting the Bosnian Muslims appear to possess the will to find out. The message that Muslims around the world took to heart was that Muslim lives did not matter to Europeans, a view that was certainly strengthened over the past 16 years by the failure to capture Ratko Mladic. The calculating lassitude of the European powers until the autumn of 1995, particularly the wariness of British politicians and commentators, seems hardly credible today.

And reaction against that paralysis – what the late Richard Holbrook regarded as "the greatest collective security failure of the west since the 1930s" – was the reason behind Tony Blair's 1999 Chicago speech embracing intervention as a moral necessity – not just for Americans. And we all know where that led us.

When Mladic's troops started separating the men and boys from the women in preparation for the massacre, it sent a shockwave into the future that has influenced events until the present day. Only a couple of months ago, as Muammar Gaddafi's mercenaries prepared to enter rebel-held Benghazi, I found myself looking up the timeline of events at Srebrenica. The memory of the massacre clearly galvanised David Cameron, who was never going to be accused of the appeasing policies of the former foreign secretaries Douglas Hurd and Malcolm Rifkind.

On hearing the news of Mladic's arrest, I instantly thought of a man I got to know when visiting Sarajevo and the Republika Srpska to write about the Srebrenica massacre. His name is Hasan Nuhanovic. He is a Bosniak who speaks fluent English and during that summer he served as translator for the Dutch forces guarding his home town of Srebrenica. When the Serbs came, he brought his father, mother and younger brother into the UN compound, in the hope that they would be protected by his contract with the UN. But the Dutch soldiers expelled his family and they were never seen again.

Hasan has borne witness to the horror of that day thousands upon thousands of times. Listening to him, I was always stuck by how utterly pathetic the Dutch were but also how little it would have taken to stop Mladic. The Dutch pleaded for air strikes before the Serbs started their bombardment and the planes actually took off, but then the French General Bertrand Janvier refused permission for the bombing because – I kid you not – the necessary forms had not been properly filled in. The warplanes ran out of fuel and had to return to their carrier, by which time it was too late.

For evil to triumph it is enough only for good men to do nothing. That is what happened in Bosnia and the thousands of deaths caused by Mladic at Sarajevo and Srebrenica were as much a product of European indifference and inaction as they were of Mladic's cruel and bullying nature. His appearance at the Hague will force us to consider again when it is right to intervene and we will remember exactly how he came to do his worst, which may not be a comfortable experience. But justice will be better served – and for victims such as Hasan so will truth – by a living defendant rather than a body riddled with bullets.