Reality on the ground aside, it probably would have been better had there been a clear legal opinion on whether the unilateral secession of Kosovo from Serbia was legal or illegal according to the current understanding of international law. However, what we got from the International Court of Justice was not a clear opinion on the legality or the illegality of Kosovo’s independence, but that international law contains no applicable prohibition of Kosovo’s independence, and as such the declaration of independence on 17 February 2008 did not violate general international law. Kosovo’s independence was legal, insofar as it was not or could not be found as illegal. The declaration of independence may not have been illegal, but does that mean Kosovo ought to be accepted as a sovereign state? Perhaps some opinion is better than no opinion. Perhaps the Court should have declared that it could not advise on this matter, rather than giving a somewhat ambiguous opinion. Whatever it did, it was going to court controversy.
I don’t have the text of the advisory opinion at the moment, and there may be clearer reasoning in it, but what is important is that this opinion will have huge repercussions on a number of areas including Republika Srpska in Bosnia-Herzegovina, Abkhazia and South Ossetia in Georgia, Tibet and East Turkestan in China, and Somaliland in Somalia. What are the conditions that will make unilateral secession from a sovereign state legal? Why should, for example, Kosovo’s independence be legal (or not illegal), whereas – hypothetically – that of Abkhazia be illegal (or not legal)? Unless there is a clear set of rules that can be applied across different areas and situations, then there will be more confusion, and there will be many regions that will use this opinion to justify their attempts at secession. It could lead to a larger number of states coming into existence, whose independence and sovereignty are questioned by a large number of other countries, which refuse to treat the seceded entities as equally sovereign.
It may be that the Court did not see as its role to create international law by specifying conditions, however, its decision will probably sow the seeds of tension within many states.