The recognition of independence for Kosovo raises serious questions of international law as well as sensitive diplomatic difficulties.

The United States and many European Union countries accept that Kosovo should no longer be formally part of Serbia.

They will recognise a limited form of independence for Kosovo, as recommended in a report drawn up for the UN by the former Finnish president Martti Ahtisaari.

The EU is sending a major law and order mission to Kosovo, made up of 1,800 police and justice officials, including judges, in effect taking over from the current UN presence.

Serbia itself, supported strongly by Russia, rejects independence for Kosovo. Serbia and Russia argue that there is no UN Security Council approval for the move and that the parties should continue negotiating until an agreement is reached.

Serbia offered Kosovo autonomy but not independence.

So what are the legal arguments for and against recognition?

The arguments for

After the war over Kosovo in 1999, the UN Security Council took control. In resolution 1244 of 10 June 1999, it ordered the Federal Republic of Yugoslavia (as it then was) to withdraw all its forces from Kosovo and hand Kosovo over to the UN.

The problem is that although the resolution called for a "political solution to the Kosovo crisis", it did not specify what that solution should be.

And there has not been any further Security Council resolution mandating independence for Kosovo.

Many Western governments argue that because 1244 does refer to general principles that G8 foreign ministers had agreed in advance of the resolution, these should be used as the basis for the acceptance of independence now.

These principles include the deployment in Kosovo of "international civil and security presences" and "facilitating a political process designed to determine Kosovo's future status".

EU legal opinion

The European Union has drawn up, as it is required to do by EU procedures, a document to justify its own mission to Kosovo and the arguments deployed are the same as the ones used to justify recognition.

The document basically argues that independence for Kosovo is within the spirit of 1244, if not strictly within the letter.

The 1244 resolution also envisaged a final status process and did not constrain or pre-determine its outcome.

"Acting to implement the final status outcome in such a situation is more compatible with the intentions of 1244 than continuing to work to block any outcome in a situation where everyone agrees that the status quo is unsustainable," it says.

The document adds that this approach "will enable, rather than frustrate, the conclusion of the final status process envisaged in resolution 1244".

And it gives approval to international recognition: "Generally, once a entity has emerged as a state in the sense of international law, a political decision can be taken to recognise it."

Nato troops under the Kosovo Force (K-For) continue to be mandated by 1244, the opinion holds.

As for the legality of the EU mission, the argument is that there is nothing to stop the EU from taking over from the UN, as 1244 simply refers to "international civil and security presences". In addition, it suggests that Kosovo could invite the EU to undertake this role.

The document interprets references in the 1244 preamble to Kosovo being part of the Federal Republic of Yugoslavia and to the "territorial integrity" of Yugoslavia as being non-binding.

The arguments against

The counter-argument by Serbia and Russia is simpler. It is that Serbia, the sovereign state, has not agreed to independence for Kosovo, that there is no Security Council resolution authorising the detachment of Kosovo from Serbia and that therefore its independence is illegal.

Some European Union members - Greece, Spain, Cyprus, Slovakia, Bulgaria and Romania - agree, though they have not blocked the EU mission.

Serbia and Russia also say that 1244 itself gives no authority for independence. They point to article 10 of 1244 which authorises "substantial autonomy with the Federal Republic of Yugoslavia" for Kosovo, meaning, in their view, that 1244 blocks independence.

And they argue that 1244 talks about international organisations being deployed in Kosovo "under United Nations auspices", which an EU mission would lack.

Russian Foreign Minister Sergei Lavrov had this to say on 12 February, in a translation by the RIA Novosti news agency in Moscow: "We are speaking here about the subversion of all the foundations of international law, about the subversion of those principles which, at huge effort, and at the cost of Europe's pain, sacrifice and bloodletting have been earned and laid down as a basis of its existence.

"We are speaking about a subversion of those principles on which the Organisation for Security and Co-operation in Europe rests, those [principles] laid down in the fundamental documents of the UN."

The main principle he refers to is that borders should be changed only by agreement.

In Russia and Serbia's view, since there is no agreement, there should be no recognition.

Paul Reynolds is the BBC News website World affairs correspondent. He can be contacted at [email protected]