When NATO forces first marched into Kosovo, their commander, Sir Michael Jackson, quite literally begged the local Serbs not to flee. When NATO leaders met at the Washington summit, they called for the reconstruction of "a peaceful, multi-ethnic and democratic Kosovo" and made bringing "democratic civil society" to the Balkans NATO's newest mission. Just two weeks ago in Washington, Gen. Wesley Clark, the man who led the Kosovo war, reiterated unequivocally the NATO goal of a multi-ethnic Kosovo.

There is no doubting the sincerity of this Western hope. Nor its nobility. But there is much doubting its wisdom.

The peoples of the former Yugoslavia do not give much sign of wanting to live with each other. In this decade, they have carried out one "ethnic cleansing" after another. The Serbs, of course, most brutally and notoriously, in Bosnia and in Kosovo. But the Croats expelled 180,000 Serbs with brisk efficiency in 1995. And in Kosovo, the ethnic cleansing of Albanians in the first half of 1999 was answered with a cleansing of Serbs in the second half. Despite NATO's good intentions and best efforts, 80 percent of Kosovar Serbs have fled.

Bosnia, too, remains divided into ethnic cantons. The multi-ethnic central government that was supposed to rebuild Bosnia in the image of the West is practically nonexistent. The hard fact is that the attempt to mold these countries into open, pluralist societies has been a failure. Why, then, do we persist in our dedication to Balkan multi-ethnicity? Would it not be wiser to give up the goal and strive instead for a lesser -- but more achievable -- good: peace through separation? It works elsewhere.

In Cyprus, separation has been the formula for the relative peace that has prevailed since 1974, when Cyprus was divided -- brutally, with ethnic cleansing -- into Turkish and Greek sectors. And what is the Middle East peace process if not an attempt to separate Jews and Arabs, leaving each in control of their own partitioned territory?

Kosovo and parts of Bosnia are nearly entirely ethnically homogeneous today. Do we really want Serbs streaming back to Kosovo and Sarajevo and Croatia? Do we really want a mass return of refugees, recreating the ethnic status quo ante the Balkan wars of the '90s? That would bring only renewed instability and conflict.

True, the integration of different peoples in one state and society is the ultimate goal. But it took two centuries for the United States to achieve the relative degree of integration it enjoys today. Nor did that model of tolerance, the European Union, spring full-grown like Athena from the head of Zeus. Modern Europe first had a run of, oh, 500 years during which time France, Italy, Germany and the rest emerged as independent, ethnically based states. Once having individuated (as the psychologists put it), they then were mature and confident enough to forfeit some of their sovereignty in the name of the larger confederation called Europe.

But that comes late. Very late.

Integration after separation. That is the idea underlying the nationalism of French Quebecers who want their own flag and U.N. seat, but who also want immediately to join Canada in an economic confederation. Scottish nationalists similarly seek independence, but would immediately come together both with England and the rest of Europe under the umbrella of the European Union.

And did we not support the independence of Croatia, Slovenia and Bosnia rather than keep them bound to some artificial multi-ethnic entity called Yugoslavia? The idea was to let these people be free. Perhaps later they might come together in some more perfect union -- but freely and as equals.

There are now 40,000 mostly NATO troops in Kosovo, 30,000 in Bosnia. If NATO insists on multi-ethnicity, it will find itself playing babysitter for decades. Why not accept the obvious? Serbs and Albanians could not coexist in Kosovo when one group, then the other, had the upper hand.

It does no good to argue, as does President Clinton, that this is just the work of a few nefarious leaders. These leaders are as much the product as the instigators of the intolerant nationalism of their peoples. What of the actual ethnic murderers and cleansers on the ground? Were they all just following orders?

Give it up. Let Kosovo achieve independence as an ethnically Albanian state. And let us similarly recognize reality in the Serb, Croatian and Bosnian Muslim parts of Bosnia. Let them associate with fellow ethnics rather than be slaves to the dead hand of mapmakers -- and the highmindedness of Westerners. A confederated Bosnia, a multi-ethnic Kosovo -- these are figments of the Western imagination. Lofty figments, but figments nonetheless. The sooner we let them go, the sooner NATO can go home.