IT may be hard to credit, but sometimes even a journalist finds it hard to believe what he is reading. On the last day of November, I read this: "Britain yesterday offered to be the first Nato country to send extra troops to Kosovo within weeks " I then attempted to compare the words with casualty lists, with puce-faced generals fuming at "overstretch" and "depletion", with Westminster rhetoric.

If this report is accurate, I thought, Britain has become a fantasy land in which flesh-and-blood squaddies are mistaken for toy soldiers, and the sun has not yet set on our imperial delusions.

Then, inconveniently, some thousands of my own past words emerged from the mist, asking to be eaten. Before Iraq, before Afghanistan, I was driving editors to the edge by insisting that the Balkans, genocide, and a duty to intervene were the only topics I was prepared to touch, week after week. I mongered war with the best of them.

Do I have anything left to say about the absolute right of nations' to self-determination? Probably not. The ethnic Albanians of Kosovo get my vote, for what it's worth. But what of the ethnic Serbs in that occupied province of a sovereign Serbian nation? They are preparing to declare themselves an enclave within an enclave. Geopolitics: the imperishable rights of my back garden versus your front gate.

It amounts to an old, hard, simple question: why are some versions of nationalism held to be plucky and honourable, others not?

Kosovo intends to be independent and free. Serbs, some of them, talk as though a plot has been hatched to carve a hole in their identity under the guise of a United Nations protectorate and a European Union "plan". The community that gifted us the language of ethnic cleansing feels that it is being scourged. And it talks of war.

Last Friday, it emerged - journalese for all murky dealings - that the EU might offer Serbia "accelerated membership" if the Kosovo majority is allowed to pursue its self-determined dream. "Carrot and stick", said the cliché: bribe, said common sense.

But hold on, said my fragile memory. The Serbs? Model Europeans, just like that? Didn't we bomb them?

"We" did. Over the plight of Kosovo, too. We did it, moreover, in large part because people who would later march to halt the Iraq fiasco wanted the bombs to fall. Blair wouldn't get away with the complicit neglect of Douglas Hurd and David Owen, we said. Britain would not stand by during another genocidal massacre.

Ordinary Serbs have no wish, I suspect, for the latest war to defend the greater glory of lesser Yugoslavia. Four defeats and no victories, outside the International Court of Justice, will cool the ardour even of a hyper-patriot. The promise of mundane European attractions - jobs and money - is probably more alluring than another bloody catastrophe for the sake of more tinpot politicians exploiting nationalism in order to disgrace a nation.

But Kosovo will not, as the jargon would have it, "just walk away". Demagogues exploit hatreds, they do not - cannot - manufacture such toxins. In the distressed province, the ethnic this and the ethnic that share common ground. But the dirt itself is the problem.

Hence that other pig-stupid, entry-level question for those of us who laud the imagined community of little national folk, respecting all cultures and beliefs: how come everyone hates everyone else?

My old friend Neal Ascherson once proposed an illuminating image of Europe ancient and modern. Think of it, he suggested, as an endless series of maps, laid one upon the other. On each of these transparencies there is the dry ink of the usual stuff: geographies, borders, empires, political and economic unions. Look: that word might be "Habsburg"; that one "USSR".

Peel these layers away, if you can. Then try to remember who the people are and why they happen to be what, and where, they are. Now and today.

Yugoslavia was an exercise in Tito's will. It lasted as long as he did. Yet the consequences of the old thug's understanding of ethnic difference have almost outlasted the duration of his dictatorship. His legacy is a hell of a mess. But is it our mess?

There will be trouble in Kosovo. The leaders of the ethnic Albanian majority are attempting to avoid provocative behaviour, but their hearts' desire is provocative, intrinsically, to Serbs. Russia is playing the old pan-Slavic game - and building the Putin imperium as it goes - while Europe filters every such issue through its own juvenile sense of self.

An example. Who in the EU is opposed to Kosovo's independence? The plan is well-established. Martti Ahtisaari, the Finn from the UN, set out the timetable. Sixteen thousand Nato personnel are in place. Nobody can claim to be surprised by the proposed solution. So who dissents?

Cyprus. Partition and self-determination are concepts liable to cause problems on that proud, divided little island. So the mighty EU falls over its mighty feet of clay simply because it subscribes to a principle: those little historic anomalies with people in them - a Kosovo, a Cyprus - are to be respected and protected. Serbia too?

The north of Kosovo province is mostly "Serb". Is it, therefore, Serbia, de facto? So what of the region's centre, where similar calculations apply? So what remains of Kosovar nationalism? And what calculations apply to nationalisms and to nation-building within the EU, a hazy concept formed of assertive nations, economic interests, and old maps?

Britain connived in ethnic-cleansing in the Balkans because the process appeared to resolve the post-Tito mess. Idealists (and columnists) demanded the bombing of Belgrade instead. Later, one version of the just war theory was used to excuse Iraq, bombing and liberation in justice's name. Your bombs bad; my bombs good. Your patriotism despicable; my nation-loving sentiment honourable.

THE Serbs believe that the integrity of their nation, and therefore their liberty, is at stake. In Kosovo, too many centuries ago to be credible, they fought a heroic battle for the sake of their nationhood. Interminable ballads will give you the details, complete with blackbirds and blood. It is, of course, absurd. It's not Bannockburn, after all, or Agincourt, or the Bastille, or Stalingrad, or Valley Forge.

In Kosovo, a brutalised people would be entitled to suggest that their identity has been defined by circumstance, and brutality. Serbs might answer that they, too, have an identity, a history, a displaced family. "Our" response seems to be that all wounds are salved by the dream of a new Europe, the continent that has erased all maps.

It is preferable, I think, to superpowers and shabby post-imperialists with imaginary squaddies to spare. It answers none of the big-little questions, however. The assumption made of Kosovo is that some people just hate other people. Quite how that is altered by EU membership remains to be explained. People hate. So let them determine their hatreds independently?

The US, Britain, Germany, France, Italy and Russia "steer" Balkan policy. The Serbs meanwhile lost control over Kosovo in 1999, when our bombs halted ethnic cleansing and left instructions on the rights of small nations to please themselves. Belgrade still pays for healthcare and schooling, though, but only for Serbs. Its people will have no truck with Albanian alternatives. Ethnic Albanians will have no truck And so forth.

The big issues of the 21st century will be trivial things, so trivial they will get people killed. And yet, still, we lack the language to say why we should even care.