JUST BEFORE Kosovo’s unilateral declaration of independence from Serbia in 2008, Vuk Jeremic, the Serbian foreign minister, warned that in Africa alone, “there are about fifty Kosovos waiting to happen.” The fifty African wannabes can take heart, as the International Court of Justice has just ruled that Kosovo’s action was not illegal, as international law contains no “prohibition on declarations of independence.”

The International Court of Justice is a conservative body whose judges are almost evenly split between those whose home countries have recognised Kosovo’s independence, and those that have not, but ten of the fourteen judges on the panel voted for the ruling. The ruling does not oblige other countries to recognise Kosovo’s independence – but it definitely shifts the balance in favour of secession.

What’s sauce for the goose is sauce for the gander: Minorities seeking independence anywhere will be encouraged by the court’s ruling. Five of the European Union’s 27 members refuse to recognise Kosovo precisely because they fear that their own minorities might use its independence as a precedent: Cyprus (Turkish Cypriots), Greece (Macedonian Turks), Slovakia (Hungarians), Romania (also Hungarians), and Spain (Catalans and Basques).

Further afield, China worries about Tibet and Xinjiang, and Russia frets about all sorts of potential secessionist movements (20 per cent of Russia’s population are minorities), so both countries sternly condemn Kosovo’s secession from Serbia. In fact, only 69 countries have recognised Kosovo. Countries with restive minorities of their own have not, and it is therefore still not a member of the United Nations.

There is an old legal adage that “hard cases make bad law,” and that is certainly at work in Kosovo. The Kosovars, who were 90 per cent of the population before the 1999 war, and now account for 95 per cent, are Albanian-speaking Muslims who were mercilessly oppressed by the ultra-nationalist Serbian regime of Slobodan Milosevic.

Milosevic abolished the autonomy that Kosovo had enjoyed in the former Yugoslavia, and by the late 1990s, his troops and police were regularly beating, jailing and killing Kosovars whom they suspected of seeking its restoration. He drove some Kosovars into a guerilla war against the Serbian regime, and then killed around 10,000 people in an indiscriminate attempt to terrorise the Kosovars into submission.

The Kosovars were not saints in all this, but they obviously owe no allegiance to a state that treated them in such a vile manner. In the end, in 1999, the United States and the European members of NATO decided that Serbian behaviour was intolerable, and waged an eleven-week war of aerial bombardment to force Serbian troops to evacuate Kosovo. Then they occupied it – and started looking for a way to leave.

The only way to get out was to create a sovereign Kosovo state, with protection for the rights of the remaining Serbian minority (now just 120,000 out of two million). When Serbia steadfastly refused to accept the independence of a province it sees as the cradle of the nation – “our Jerusalem,” in Vuk Jeremic’s words, the US and the major European countries told the Kosovars that they could declare their independence unilaterally.

Kosovo could not reasonably be expected to stay in Serbia after all that has happened, but it is a hard case, and it makes bad law. Or at least, it changes the law in ways that we may regret.

The International Court of Justice is right: International law does not ban declarations of independence. But the deal that underlies the creation of the United Nations, and that has spared us from great-power wars (and probably quite a few smaller wars) over the past sixty-five years, does forbid any changes in the borders of UN members that are imposed by force.

That deal is embedded in the UN Charter: Thou shalt not change a border by force. What they really intended in 1945 – quite understandably, given what they had just been through – was to stop cross-border wars of aggression. In practice, however, the Charter has also been used to delegitimise unilateral declarations of independence all over the world.

Once upon a time, a breakaway province could establish its independence simply by demonstrating that it controlled all of its territory and had established a viable government. That is no longer true. The UN has become a trade union of the existing sovereign states, operating as a closed shop and refusing to recognise secessions, even after they have succeeded in fact.

It was a largely unintended side effect of the UN Charter, and although it has suppressed violence in some places, it also helped to perpetuate terrible injustices in many others. The decision of the International Court of Justice undermines this interpretation of the Charter, and probably means that more secessions actually succeed in the end.

Whether that is a good thing or not depends on which side of the fence you are on, but it probably means more violence, at least in the short term. (Gwynne Dyer is a London-based independent journalist)