Most modern negotiating theory is founded on the notion that the outcome should be "win-win".

Both sides get something, even if not their complete desiderata, and both come away prepared to implement and abide by the terms of the deal.

In such negotiations, the bottom line - the line below which no agreement genuinely offers fewer penalties than any agreement - is habitually pretty low, since the presumption is that both sides share an ultimate objective and will make efforts to accommodate each others' essential interests.

The Versailles settlement after the First World War taught some bitter lessons about driving too hard a bargain.

And even during the depth of the Cold War, major East-West arms control agreements were based on a shared objective of reducing the risk of nuclear war despite uncompromising ideological differences.

Previous dealings

Now apply this "win-win" thesis to dealing with President Milosevic.

It rapidly becomes apparent that he does not share the West's objectives and cannot be trusted to implement agreements unsupervised.

Own agenda in negotiations over Bosnia

Let us look at the track record. Quite apart from the Rambouillet discussions over Kosovo, there is extensive Bosnia-related experience. Let me illustrate.

To support the Vance-Owen peace plan for Bosnia, and subsequently an agreement based on the so-called Contact Group map, it was necessary to get Belgrade to recognise Bosnia as a separate entity in international law.

Milosevic knew that the prize for him was the lifting of sanctions following an agreement which could flow from recognition by Belgrade. But Milosevic maintained that he could not negotiate under duress and insisted on the prior lifting of sanctions.

He did not however commit himself to recognition were sanctions to be lifted nor, indeed, to anything else the Western negotiators were asking for.

Nor were the Western negotiators able to establish an agreed end point from which to work back to a fruitful negotiation.

Hidden agenda

President Milosevic would listen but not engage. Then, as now, only he called the shots in Belgrade.

It became evident that for Mr Milosevic, negotiation was not about striking a deal which balanced the interests of two sides but was about securing his own (unadmitted) agenda, quite different from that of Western governments and at the price of their agenda.

President Milosevic plays for high stakes

For him, negotiation was a battle of wits, each move or proposal by the other side being examined for the tactical advantage it might offer in reaching his own goals or for the weakness that it might be thought to reveal in the opponent's position which could be exploited.

Offers by him had a similar tactical aim: to divide the opposition and facilitate his agenda. In Bosnia, President Milosevic negotiated for him to win and for his opponents to lose.

He was prepared to play for high stakes and, like a gambler, hold his nerve and not settle until he judged he could do no better.

Key concession

President Milosevic finally settled over Bosnia at what he presumably judged his maximal point.

In the summer of 1995, the fortunes of war on the ground were turning against the Bosnian Serbs and, for the first time, they were losing territory in the face of a Croat offensive.

President Milosevic was then offered a key concession by the American negotiator, Richard Holbrooke: the Bosnian Serbs could have their own self-governing territorial entity inside Bosnia, guaranteed in the peace agreement.

He had got as near to his goal as he could. If he had waited longer, this key concession might have disappeared and sanctions, which were hurting Serbia, would have continued.

Lessons of Bosnia

It is widely, and erroneously thought that the bombing of Bosnian Serbs' command and control positions was the key event in bringing President Milosevic to terms.

Mr Milosevic's own personal survival has been threatened

Bombing played a part, undoubtedly, in damaging Serb military capabilities. But it was not the only event, and not necessarily the single most important element in getting Mr Milosevic to Dayton.

So what are the lessons of Bosnia? First, since Mr Milosevic does not share Western objectives and deals with him must, effectively, be imposed, considerable leverage will need to be applied.

Threats of hostile action, by themselves, are unlikely to be enough. If, in Bosnia, Nato's threat of bombing had actually to be implemented to get results, it should come as no surprise that, in relation to Kosovo of all places, Milosevic was unlikely to be deterred by simple menaces.

His previous experience of Nato bombing had hardly been terrifying.

Nato's 'win-lose' strategy

Secondly, therefore, if Nato were going to hang, as it did, the central part of its strategy on a threat, it had also to have a credible fall-back if the threat failed - as it did.

It needed to recognise that in resorting to bombing, it was itself moving from a "win-win" strategy (everyone gets something from Rambouillet, if not everything they want) to "win-lose" (Nato has to win and Milosevic must lose).

The reader can judge for himself whether Nato was wise to declare a non-combat strategy on the ground and whether it has yet supplied itself with sufficient means to win.

Thirdly, it is clear that "concessions" made by Mr Milosevic, such as declaring troop withdrawals from Kosovo of unspecified size and duration, are not designed to meet Nato's terms, but to sow division in Nato's ranks to get the bombing stopped, in the sure knowledge that it would be hard to resume.

Hence the importance of displaying unity in confronting him. Were he to succeed in getting the pressure on him lifted, his past record teaches that far from this inducing amenable behaviour, he would then bargain as far, and for as long as allowed, to get as near as his goal as possible.

Tactician, but no strategist

Mr Milosevic has to perceive that he is about to suffer, or is suffering, unacceptable losses before he will yield.

Given that the issue is sovereignty over Kosovo, and that his personal survival is at stake, he is potentially capable of pushing these to catastrophic levels unless stopped first by superior force.

Lastly, Nato can, and must, win. For it too, Kosovo has become an existential question.

Mr Milosevic's track record contains one more, vital, piece of evidence. Master tactician he may be. But strategist he is not.