Russia's motives stem mainly from its ambition to continue playing a major role in world diplomacy - picking up where the Soviet Union left off.

The BBC's Alan Little reports from Moscow on the long friendship between Russia and Serbia

It currently faces the threat of being sidelined in Eastern Europe - much of which fell into its sphere of influence even before Soviet times - by military action orchestrated by Nato.

Russia has repeatedly tried to play the role of peacemaker in the Balkans - just as it helped to avert Western military action against Iraq earlier this year.

What Russia needs to avoid most of all is a situation where it alienates its Western allies and creditors by vetoing economic sanctions or military intervention in the United Nations Security Council - only to see Nato take the initiative without UN authorisation.

Parliament's opposition

Last minute diplomacy: Russian envoy Igor Ivanov with the Serbian leader

Another concern for Moscow is that Nato air strikes against Bosnian Serbs in 1994 and 1995 always drew howls of protest from the vocal pro-Serb lobby in Russia's parliament.

Their criticisms were directed not only at Nato, but also at the Russian government, which they said had revealed its weakness by failing to prevent the strikes.

Pro-Serb sentiment comes naturally to Russian nationalist politicians, who identify with the cause of a Slavic and Orthodox group in conflict with a Muslim community.

Unlike the Bosnian Muslims, the Kosovo Albanians are not only mainly Muslim, they are also non-Slavic.

Russian public opinion

Andrew Harding: an issue most Russians agree on

Russian public opinion has never mirrored the indignation voiced by nationalists, and occasionally by the Russian media, at what they allege is the West's anti-Serbian or anti-Slavic bias.

But it is more sensitive to claims that the West has undermined Russian prestige by ignoring its objections to military intervention.

The Russian government backed the UN Security Council resolutions that paved the way for Nato intervention in Bosnia, but publicly challenged Nato's right to use force in Bosnia without gaining the consent of the Security Council for each individual strike, and without consulting the Russian government in advance.

Moscow's backyard

There are two other reasons why Russia may be especially reluctant to see international military intervention in Kosovo.

One is that Kosovo, unlike Bosnia, is not an internationally recognised independent state.