LONDON -- It is 20 years since Turkish troops landed on the northern coast of Cyprus, beginning the process whereby the island was divided de facto between its Greek and Turkish communities. In that time, the United Nations has made numerous attempts to reunify Cyprus, and all have come to grief. As far as the Bosnian war goes, Cyprus is a salutary reminder to those who think it will be possible to reconstitute Bosnia-Herzegovina as a state in which members of different nationalities once again live side by side.


Like Bosnia, Cyprus provides a chilling example of "ethnic cleansing" in the wake of armed conflict. In 1960, when Cyprus received its independence from Britain, the island had 574,000 inhabitants living in 635 settlements, of which 392 were purely Greek, 117 were purely Turkish and 126 were ethnically mixed. Since 1974, practically every Greek living in the Turkish-occupied north has been forced to leave for the south, and all but a handful of Turks living in the south have gone north.


The outside world usually blames the Turks for the de facto partition of Cyprus, in the same way that it blames the Serbs for the same situation in Bosnia. Yet one ought to remember that the Turkish invasion followed a coup d'etat in Cyprus that Greece's then military rulers launched in order to put into power Nikos Sampson, a notorious Greek Cypriot terrorist. In addition, in the run-up to independence in 1960, the Greek Cypriot elite was actually in favor of unification with Greece, a prospect that the island's Turkish minority naturally abhorred.


Of course, nothing can excuse the Turkish expulsions of Greeks from northern Cyprus since 1974 and the deliberate settlement of Turks from Anatolian Turkey in their place. The proclamation of a separate Turkish Cypriot state in 1983 suggests that the Turks were never really interested in reviving Cyprus as a country of mixed populations.What, then, can be done? In one capacity or another, UN troops have been stationed on Cyprus since 1964. Yet a solution is so far off that UN Secretary General Boutros Boutros Ghali recently indicated that the UN might do better to reallocate its scarce peacekeeping resources elsewhere.


The most logical settlement would be a loose federal Cyprus with guarantees for the Turkish minority. But this is utterly unacceptable to the Turks, and the only way to secure their consent would be for Turkey's Western allies to apply economic and military pressure on them. It seems inconceivable that the United States or anyone else will do that.


In cases such as Cyprus and Bosnia, the lesson is that, unless an outside power such as NATO is prepared to use force to achieve results, nothing much will change. The self-styled Turkish Republic of Northern Cyprus and Serbian Republic of Bosnia may be economically crippled dwarf states, but they will always find a way of struggling on if there is no outside pressure. In Bosnia's case, economic sanctions on Serbia may help to delay the outcome, but ultimately Bosnia is doomed to partition unless there is forceful UN or NATO intervention.


Partitions and forced population transfers may offend the conscience, but Europe really has little right to complain about them if it refuses to intervene to reverse them. It was, after all, Europe that gave birth this century to the principle of separating nationalities into individual states. Cyprus and Bosnia are the chickens coming home to roost.