Leading article: An arrest that enables Serbia and Europe to turn a page

Ratko Mladic's capture marks a symbolic end to the chaos that followed Yugoslavia's break-up

A grisly chapter in the history of the Balkans has been closed with the arrest of the Bosnian General Ratko Mladic, who had been on the run for an extraordinary 16 years. The former head of the Bosnian Serb army was the most prominent war crimes suspect still at large. His extradition to the International Criminal Tribunal in The Hague, where his civilian partner Radovan Karadzic is already on trial, marks a symbolic end to the chaos that followed Yugoslavia's break-up at the end of the Cold War.

The grim shadow of Mladic falls across one of the darkest places in modern Europe, Srebrenica, a city of ghosts, where 8,000 Muslim men and boys were ruthlessly slaughtered in 1995 when Mladic's troops entered a United Nations "safe haven" for refugees.

The wanton, week-long rampage saw the worst civilian carnage since the Second World War; children had their throats slit before their mothers' eyes. Mladic is charged with 15 counts of genocide, crimes against humanity and other atrocities.

His arrest, in contrast to the killing of Osama bin Laden last month, will generate a trial which will exorcise some of those ghosts – a process of which the region was cheated when Slobodan Milosevic, the Serb strongman and architect of the Bosnian wars, died before a verdict could be passed on the heinous crimes of those dark days. Justice has been a long time coming. In the early years, Nato powers did not press for a resolution for fear that a remorseless manhunt might jeopardise the fragile post-war ceasefire. Instead, they played a long game, making it clear to Serbia that it could never hope for membership of the European Union while war criminals were sheltered in its midst.

The Netherlands, whose UN soldiers were humiliated in the Srebrenica safe haven, has taken a hard line in exercising a veto. Serbia has been resistant. Ultra-nationalist factions within the military, intelligence, para-military and political establishments have protected war crimes suspects. Many Serbs still see Mladic as a patriot hero. Just last week, 51 per cent of citizens said they would not hand Mladic over to The Hague.

But change has been coming, slowly. After the general election in 2004, a firmly pro-European politician, Boris Tadic, did well enough to build a pro-European coalition and become Serbia's President. In 2008, he felt strong enough to replace the head of its secret police. The capture of Karadzic swiftly followed, by agents who were actually hunting Mladic. Earlier this year, they tracked down Mladic's diaries, which could provide important evidence in the coming trial.

The maintenance of international pressure has been key. The chief prosecutor from The Hague had just complied a report on Serbian foot-dragging which was to be debated by the UN Security Council in two weeks. And Mladic's arrest was announced the very day that the EU High Representative for Foreign Affairs and Security, Baroness Ashton, arrived in Belgrade for talks. There are still questions to answer. Who helped Mladic to hide for so long on Serbian soil? On whose authority? Who turned a blind eye? More arrests among a network of Serb military and security officials may yet follow. And the war crimes fugitive, Goran Hadzic, who led the Serb insurgency in Croatia, is still at large.

But a page has been turned not just for Serbia but for Europe. Slovenia already has EU membership. Croatia is moving towards it, as are Bosnia, Montenegro, Macedonia, Albania and, more controversially, Kosovo. Serbia now looks set to turn from its traditional ally, Russia, and look westward. The hole on the European map between Italy and Bulgaria and Romania is being filled. Serbia's return to the comity of nations is good for the peace and prosperity of the entire continent.