Kosovo's unilateral declaration of independence (UDI) in February 2008 sharply divided international opinion. On the one side, the US and many leading members of the EU argued that there was no alternative but to allow Kosovo to go its own way. Regional stability in the Balkans required nothing less than the recognition that Kosovo represented, for better or for worse, a unique case under international law.
In contrast, Russia and China, supported by the majority of the world's states, argued that Kosovo could not be regarded as sui generis. If it could declare independence then the way would be open for others to follow. It was in this context that Serbia managed to secure a resolution putting the very question of the legality of the declaration of independence before the international court of justice.
The proceedings themselves proved to be fascinating. While the countries that opposed the declaration of independence resorted to fairly standard arguments about the sanctity of state borders, the states that had recognised Kosovo used an array of approaches to justify Kosovo's right to secede from Serbia. Perhaps the key argument made was that a declaration of independence has no legal meaning in itself. It is the act of recognition that counts, and this is a political decision that remains the sovereign prerogative of states. In other words, it was suggested that the court had been asked the wrong question.
But there were other arguments: for example, that Kosovo had a special position under the Yugoslav constitution; that the human rights abuses suffered by the Kosovo Albanians during the Milosevic era made further Serbian sovereignty over the province untenable; and that after a number of years under international administration it should have the right to full independence. One argument even went that the court should rule in favour of the UDI as a decision to declare it as being contrary to international law would simply be ignored. If it went against the will of the US and major EU states, it would simply become irrelevant.
In the end, the judges opted to take the narrowest possible approach to the question and focused on the declaration of independence, rather than the legitimacy or legality of independence. On this issue, they went with the supporters of Kosovo's independence. As the majority of the judges saw it, a declaration of independence does not appear to be contrary to international law.
This is undoubtedly a victory for Kosovo – but only of sorts. It could have been told that the UDI was illegal, which would have put all those states that recognised it in a very tight spot. However, the narrowness of the opinion means that the positive effects for Kosovo in the short- to medium-term are likely to be rather more limited than one might expect. States, such as Russia and China, that oppose Kosovo's independence on the grounds that it is an illegal act of secession can hold to this position. The court did not, after all, issue an opinion on this point. They can argue that by actually recognising Kosovo they will be legitimising what they still believes is an illegal act of secession. This will prevent Kosovo from joining the UN and other international organisations. For this reason, it still seems that a mutually acceptable political solution will have to be found.
As for the wider picture, what sort of impact does this have for other secessionist entities seeking statehood? In short, not that much. It means that any group or territory can declare independence. What matters is whether they are recognised. This has always been the hard part, and will remain so.
James Ker-Lindsay, senior research fellow on the politics of south east Europe at the London School of Economics.