The Gulf war was fought to liberate Kuwait. No sooner was that achieved than, with UN Security Council Resolution 687 of April 11th, 1991, the United States-led coalition set itself a second task: to divest Iraq of its weapons of mass destruction.

Not only has it failed in that task, but it now seems that the US, and any country willing to go along with it, will have to wage another Desert Storm operation to achieve the goal. That, in effect, is what Saddam Hussein is daring it to do.

It is a high-risk strategy. President Saddam, an inveterate gambler, has always left himself a line of retreat and, absolute despot that he is, has managed to take it - then sell it to his crushed and weary people as the latest triumph of his genial statesmanship.

His past and his personality suggest that if ever he felt mortal peril, he would gamble his all - to survive again, or make the world pay the highest possible price for his destruction.

President Saddam can be very patient as well as very reckless. Even as he pushes to dangerous extremes, he does so with a deliberateness, calculation and perseverance which ensures that his next great gamble will be as well prepared and formidable as it can be. His latest, long-drawn confrontation with Unscom, the United Nations' disarmament team, is no exception.

It can now be said to have begun on March 16th, when, with the solemnity he reserves for big decisions, President Saddam presided over a special session of his Revolutionary Command Council.

Its effects were first felt in June with the sudden, systematic harassment of United Nations inspectors at "sensitive" or "presidential" sites. Rolf Ekeus, the outgoing Unscom chief, warned then that if "the present situation remains unresolved we shall come to see the Gulf war as a brief parenthesis with no lasting significance".

They were felt again in October, when Baghdad expelled the US inspectors. Mr Ekeus's successor, Richard Butler, said: "I don't think the Security Council had faced a more serious challenge, maybe since it was created."

They will be felt again in what, with advance publicity, Iraq bills as "the battle of the presidential palaces".

President Saddam is not just indicating that he wants to keep his weapons of mass destruction and get UN sanctions lifted - he has long been doing that. He has embarked on an active strategy to bring it about, blowing up the basic assumption on which Resolution 687 rested - that he would sooner or later acquiesce in the bargain of dismantling his weapons in return for the lifting of sanctions.

He was always going to conceal whatever weapons he could - it recently transpired that even his top foreign policy executive, the deputy prime minister, Tariq Aziz, knew nothing about his biological programme when it first came to light in 1995 - but he would surely yield up those that had been uncovered.

Self-interest seemed to dictate it. Money had always been a key source of his strength. Worse, his people were sinking into such misery that their discontent and despair seemed bound in the end to undermine even his terrifying grip on power.

But time - and £74 billion sterling forgone in oil revenues - has undermined that assumption, which underestimated both his ability under extreme conditions to keep his people down and the importance he attaches to the weapons.

They are more to him than the piece de resistance in his panoply of fearsome repression; more than the instruments by which, in some resurgent future of which he dreams, he can again indulge his megalomania. They are a necessity, the sine qua non of his survival, his insurance policy against the one thing that could ever wrest them from him - an all-out military assault.

He strenuously denies that he still has such weapons or the missiles to deliver them, but dismisses contemptuously the very idea that his claims need be supported by evidence.

Experience, and Unscom's research, have proved President Saddam's word is worthless. What easier, more obvious course than to hide his arsenal in some of his 70-odd "palaces", then invoke "sovereignty" and "national dignity" against the inspectors when they get close to their quarry?

What conceivable "dignity" remains to a leadership that has lost control of the Kurdish north, ceded half its air space to Western warplanes, and acquiesced in sanctions and Unscom itself?

The more stridently President Saddam asserts his innocence, the more suspicious Unscom and Western governments become about the variety and scale of the horrors he possesses: sufficient amounts of the biological agent anthrax and the chemical agent VX to kill billions of people; Scud missiles to deliver them; cruise or air defence missiles, helicopters and crop-spraying aircraft that have been, or could be, converted for the purpose; longer-range missiles believed to be under development; and a nuclear capacity, needing only fissionable material to be operational within a year.

One thing that President Saddam certainly does sense - and takes heart from - is that, as the confrontation deepens, his US adversary is less and less confident of winning it, and while it looks tough, it does not feel it, diplomatically or militarily.

The US looks tough when it keeps coming up with the new things which, in addition to giving up his weapons, President Saddam must do to earn a lifting of sanctions.

He must prove his "peaceful intentions" in accordance with the preamble of 687; or respect human rights, in accordance with another resolution, 688. Finally, early last year, the US Secretary of State, Madeleine Albright, formally enunciated what the US had long implied: the embargo would end only with President Saddam's removal from power.

This has defeated the purpose of 687. If President Saddam really had wanted to negotiate, the incentive to do so has been destroyed. Even if he had no intention to negotiate, the move has enabled him to mobilise international opposition to US diplomacy.

The eternal, obsessive insistence on sanctions, punctuated by occasional military strikes, is not tough at all. On the contrary, it is a wilful evasion in populist guise of what the US should be doing if it takes its own, highly alarming assessment of Iraq's intentions seriously.

Having wasted the only other serious course of action - backing an effective Iraqi opposition - it should be marching on Baghdad, or doing whatever it takes to trigger President Saddam's downfall.

The only sure way to get President Saddam to disgorge his weapons is to get Saddam himself. It is a potentially horrendous mess - one that could put the Yugoslavian conundrum in the shade - towards which the US, in its paralysis, and the region are drifting.

Yet there is one very simple, if very improbable, way in which the US could do much to repair its damaged position. It could remind itself that, more than just the disarming of Iraq, Resolution 687 calls for ridding the entire Middle East of weapons of mass destruction.

A truly impartial, comprehensive interpretation of 687, a convincing display of US determination to bring Israel, as well as Iraq, within its scope, could work wonders with important Arab, and other, members of the shattered Gulf war coalition.

Such a move would greatly strengthen its diplomatic hand, and ensure that it would command more than merely Israeli, possibly British and a fickle kind of Gulf support for a final military showdown.

President Saddam would almost certainly threaten to use his weapons of mass destruction in a desperate bid to head off the showdown. Should blackmail fail, he would almost certainly carry out that threat in a last, demented, Samson-like act of vengeance to which - say those who know him best - he would be temperamentally drawn, and to which his career as one of the most evil, utterly destructive despots of our times, would have impelled him.