It is not easy to be an optimist in the Balkans. Serbia’s neighbours were gamely insisting yesterday that the country’s general election result, which saw a sharp increase in the hardline nationalist vote, does not necessarily end the attempt to woo Serbia from its angry isolation. They point out that, while the Radical party, which refuses to concede the loss of Kosovo, won 28 per cent of the vote, the pro-reform Democratic party of President Tadic doubled its support to 23 per cent. Together with other parties seeking an end to the political stalemate, it still commands a majority of the parliamentary seats. European Union foreign ministers also shrugged off the success of the ultranationalists, and hoped that a pro-European government would be formed. They are whistling in the wind. The key issue determining politics in Belgrade is Kosovo. And there are few signs of compromise emerging.

It is eight years since Nato troops forced Yugoslav troops out of the ethnic-Albanian-dominated province. Since then, Kosovo has been in constitutional limbo. Administered under a United Nations mandate, it has repeatedly demanded full independence from Serbia, but has been rebuffed by a nervous Security Council unwilling to sanction a move that could rekindle competing nationalisms. Nato troops are still needed to protect the embattled Serb minority, which naturally and vigorously opposes independence. The issue was again postponed in order not to give the Right further ammunition during the Serbian election campaign. But, on Friday, Martti Ahtisaari, the UN envoy, is due to outline his proposal on final status. He is almost certain to recommend “supervised” independence.

Serbia’s politicians are bracing themselves for a backlash. President Tadic is pushing to restart talks with the EU, suspended last May, while quietly mending fences with Serbia’s neighbours, and stepping up moves to catch indicted Bosnian war criminals. But he needs to renew a coalition with the outgoing Prime Minister, Vojislav Kostunica, if they are to deny office to the Radicals. Both men have reluctantly accepted the secession last May of Montenegro. Both have denounced the malign legacy of Slobodan Milosevic. The stumbling block remains Kosovo.

Mr Tadic has told fellow Serbs that Kosovo, considered by most as the cradle of their history, culture and religion, may already be lost. He sees no chance of forcing its two million Albanians back into Serbian sovereignty. Mr Kostunica, despite his crucial role in ousting Milosevic, echoes his nationalist rhetoric in insisting that Kosovo remain part of Serbia. And he has the powerful backing internationally of Russia, which has long played the role of Serbia’s patron and fears the precedent of a rebellious province seceding. The most that he will concede is a form of autonomy.

Should the two fail to agree, the Radicals may come to power by default. Most Serbs, and Serbia’s neighbours, would see that outcome as a disastrous step back into a defiant and futile isolationism, which would sabotage attempts to secure Balkan stability. Kosovo already has de facto independence. The West would be wise to postpone its formalisation de jure yet again — at least until Belgrade can be coaxed into accepting reality. This may be the inevitable contemporary cost of avoiding renewed violence in an historically volatile region.