It is even possible that we could both bomb the Serbs and betray the Kosovars. We could even betray our own high principles - democracy, human rights, and so on - if we find that the Muslims of Kosovo insist on independence rather than autonomy.
The approach of international conflict in the Balkans has been so slow, and so littered with the usual cliches of threat and counter-threat, that it is difficult to realise that we are approaching the endgame. Both Nato and Slobodan Milosevic have reached - cliche again - the point of no return. Serbia cannot surrender Kosovo to foreign forces. Nato cannot back down from its obligations to the Kosovars.
Last week, when the Kosovo delegation coldly signed away their independence in return for limited self-government, the men and women who had hitherto played a starring role in the drama preferred to stay away. British foreign secretary Robin Cook was in Bonn, as was French foreign minister Hubert Vedrine.
Madeleine Albright said she "wished she could be there" - she could have been, of course - but stayed in Washington. The stars suddenly wanted out of the movie. No one - save the luckless US envoy Christopher Hill, his Austrian EU colleague and Russian negotiator Boris Mayorski wanted to be there. And Mr Mayorski sullenly refused to sign the documents as a witness.
Russia was not going to be a party to this particular surrender of Serb sovereignty, nor lend its name to a treaty which may lead to a Nato war. Russian foreign minister Yevgeny Primakov may still warn Mr Milosevic of his behaviour - and condemn the slaughter of ethnic Albanians in Kosovo - but his imminent trip to Washington will show that Moscow is not going to join the Nato crusade. Nor are the Russians unaware of the divisions within Nato.
American enthusiasm for an offensive against Serbia has scarcely wavered during the weeks of negotiations at Rambouillet and Paris. But Europe's threats - symbolised by Mr Cook's finger-wagging diplomacy - have grown steadily fainter as the prospect of conflict approached. Wars in south- east Asia and the Middle East invariably spread to neighbouring countries, their effect rippling like an earthquake throughout the region. Why should Europe be any different? And this, remember, will be a European war - far from the United States, but well inside our own continent.
Once we start bombing Serbia, will Montenegro seek independence - and our protection - from Belgrade? Will the Albanians of Macedonia declare for the Albanians of Kosovo - or, worse, a greater Albania? Could Greece tolerate internal dissent in Macedonia? Would the Bosnian Muslims - an outside chance, this, but one that Nato has thought about - choose this moment to conclude unfinished business with the Bosnian Serbs and retake the Drina Valley? In London, we are backing the Americans (more or less). But the closer they are to the Balkans, the less enthusiastic are our European partners. Italy and Austria and Greece really do not want a war. And who can blame them?
Of course, there are cracks in the Serbian edifice. Milosevic's opponents are being quietly wooed by Nato ambassadors who know that two of Serbia's top military strategists were fired by the Yugoslav president earlier this year.
But Serb "democrats" fear that a war will give Milosevic the opportunity to declare martial law, crush the remaining free press in Belgrade, arrest dissidents and, perhaps, seize back control of Montenegro. Kosovo Albanians would then be fair game for the Yugoslav armed forces; since the Kosovars would invariably support Nato, they would be regarded as a fifth column, vicious traitors who must be ruthlessly exterminated.
As usual this weekend, we are looking after our own, hoping to extract the Kosovo monitors before the Serbs can take them hostage - while leaving the Kosovars to their fate. The KLA will, for a while, abide by the treaty signed in Paris on Thursday; they will wait for the autonomy that Nato guarantees - until it becomes clear that Nato will not ride to the rescue. If Nato bombs the Serbs, will the KLA remain in their villages? And if they do not - and the Serbs attack the Kosovars - will the western armies in Macedonia help them? Alas, that is not what the Kosovo delegation signed up for in Paris last week.
So will the Kosovars themselves stay united? The Americans are desperately worried that they will not; hence their insistence last week that the Kosovo delegation should return to Pristina for "necessary consultations", the need to remain unified and "stay in touch" with Washington. Hence the sudden invitation to the Kosovo delegation to visit Nato headquarters for a briefing on what they can expect - and not expect - in the way of support. For if the Kosovo Albanians seek independence rather than autonomy once a Nato bombardment begins, the European casus belli - the refusal of the Serbs to abide by the Paris peace agreement which they refused to sign - disappears. And then the world will ask why Nato has gone to war.
Yes, Mr Milosevic might still, at the last moment, give way. But the odds are increasingly against it. Serb president Milan Milutinovic promised in Paris last week that the Yugoslav armed forces would fight in the event of a Nato attack. Besides, Milosevic allowed the Serbs of Krajina to be driven from their homes by the Croatians, and abandoned the Serbs of western Bosnia. He is unlikely to bow to American pressure in order to save Serb lives in Serbia. So what chance of a happy ending?
PROFILE, PAGE 27