Worldwide horror at death of reformer

The brutal murder of Zoran Djindjic has not only plunged his country into political turmoil, but poses a new threat to the stability of the region.

The EU and Nato last night expressed their horror at the assassination, while pledging to carry on supporting the work of reform in Serbia. But diplomats accept that the death of Mr Djindjic is a heavy blow and that his brand of courage, charisma, pragmatism and reforming zeal will not be replaced easily. As one EU official said: "There is no obvious replacement in the wings."

Gerhard Schröder, the German Chancellor, described Mr Djindjic as a beacon of hope for Serbs who played a decisive role in Serbia's "return to the community of European democracies". He added: "Europe saw him as an important guarantor of the peace and stability of the Balkans."

Jacques Chirac, the French President, said history would remember Mr Djindjic for "making the choice of democracy and reforms to guide Serbia on the road to Europe".

Lord Robertson of Port Ellen, the General Secretary of Nato, also praised Mr Djindjic as a reformer. "He was a true believer in peace and pursued with vigour the legitimate ambitions of his country to fully integrate into the Euro-Atlantic community of nations," he said.

At The Hague, Carla Del Ponte, chief prosecutor of the international war crimes tribunal, said she was sad to lose her strongest ally in the Belgrade government, referring to Mr Djindjic's support – despite fierce opposition at home – to the capture and extradition of war crimes suspects.

But while Mr Djindjic had made many friends in the West, he also had many enemies at home – not least the nationalists who still pay allegiance to Slobodan Milosevic, the ousted president currently on trial at The Hague.

The key to what happens next lies in the succession to Mr Djindjic. The assassination comes at a delicate time, only weeks after the creation of the new state of Serbia and Montenegro. The uprising that ousted Mr Milosevic demonstrated the popular desire for change. But reforms are just taking shape and the new nation is feeling its way towards a Western democracy based on the rule of law.

There are already fears that Mr Djindjic's successor could awaken the conflicts in southern Serbia and Kosovo, causing a new outbreak of instability. As one diplomat put it: "This is not just about Serbia, but about the countries around it. You could see a domino effect."