Leading article: The benefits of a flexible approach to borders

Montenegro has voted, and by the narrowest of margins this former republic of now defunct Yugoslavia has decided to make the final break. It will leave the union with Serbia, and go it alone as a separate state. The final majority will be official in two weeks' time, but already there is no going back. Montenegro, with its 670,000 inhabitants, is set to become Europe's newest state.

At once warm greetings flowed into the budding national capital, Podgorica. Even Serbia sent grudging congratulations. The erstwhile partners are now preparing negotiations on a division of assets. So far, the process has been remarkably civilised and calm. Even more remarkable has been the nonchalance, uninterest almost, with which the break-up has been countenanced elsewhere. In Europe, at least, it seems to be recognised that there are times when divorce is for the best.

Time was when the very notion that part of another country could declare itself independent, with or without a referendum, was taboo. Partly, perhaps, because of the turmoil that so many people had suffered through two world wars, national frontiers became sacrosanct. The unification of Germany broke the taboo in a big way. With the Berlin Wall demolished in such inspiring fashion, what was there to stop other borders being broken or remade? The USSR disintegrated. Czechoslovakia split in two; Slovenia turned its back on Yugoslavia and the remaining republics waged a short, but brutal, civil war as they revived their independence.

More than 15 years since the unification of Germany, Europe consists of many more countries than it did. Happiness is suddenly fashionable, but observation suggests that those people who have gained or regained their independence are happier than they were when they were in thrall, or unhappily joined, to another. They are more productive, richer, and they take seriously their responsibilities as states.

The proliferation of small states has had no significantly destabilising effect on the continent except where, as in Yugoslavia or the former Soviet Union, state and ethnic borders had been artificially drawn. Concern that a country could be too small to be viable has not been justified. Nor has the redrawing of borders turned out to be as contagious as was feared. Not all devolution movements have ended in secession; for some, greater autonomy suffices.

All this helps to explain why independence for Montenegro has been hailed more as a promise than a threat. It also poses a question that would have been unthinkable a generation ago: might it not be time to reconsider the principle that national frontiers should always be immutable? Perhaps the new map of Europe could offer a lesson for other parts of the world. How much misery is caused in parts of Africa and Asia because the borders do not match ethnic composition, or because economic and demographic shifts challenge colonial-era borders?

The risks of change must not be under-estimated. It may be that altering frontiers is possible in Europe only because there are now strong institutions and because desire for membership of the European Union acts as a restraint. But would a federal, or even separated, Iraq be more violent than it currently is? Would a Kurdish state really be the threat that adjacent countries fear? Might the earlier formation of a Palestinian state have prevented the present bloodshed? We cannot know. We do know, however, that the revision of borders over the past decade or so has not resulted in the anarchy that was widely feared. And we wonder, given the experience in Europe, whether a more flexible attitude to frontiers might not produce similar benefits elsewhere.