When the Berlin Wall collapsed and the Cold War came to an end, optimistic souls thought the United Nations might be able to implement the vision of those who established it and drew up its charter at the end of the second World War.

With the world no longer locked in a permanent standoff between two superpowers, perhaps at last the dream of international order and harmony, supervised and policed by co-operating member-states would come true.

Reality bites, however, and the practical experience of the past 10 years has taught the UN and the international community some sharp lessons.

Despite all the difficulties of the Cold War era, at least it had the virtue of stark simplicity. It also let the UN off the hook in many cases, since the influence of the Americans and the Soviet Union could be exerted behind the scenes on different parties to a conflict, helping to bring about, if not a solution, at least a non-violent stalemate.

For the past decade the UN has not been able to hide behind the skirts of the superpowers, and its direct involvement in a variety of conflicts has often left it cruelly exposed. Last March the Secretary-General, Kofi Annan, set up a panel of experts to prepare a special report on the reform of peace operations, which is due out tomorrow.

The problem for the UN - and it is in part a consequence of the ending of the Cold War - is that the world has become a more anarchic place, with international relations and even wars no longer conducted on the semi-logical lines of the past.

Whereas previously UN troops were often the thin blue line between two states that had been at war and were now relying on the blue-helmeted soldiers to police their ceasefire, conflicts are rarely conducted nowadays on these superficially civilised lines.

Confronted with new and unpredictable situations, the UN has at times given an impression of moral paralysis. Thus there was severe criticism of the international body when it failed to stop such outrages as the killing of Muslims in Srebrenica during the Bosnian conflict in 1995 and the massacre of ethnic Tutsi in Rwanda in 1994.

Mr Annan himself posed the question when the panel was announced: "What do you do if the peace you are trying to keep breaks down and large numbers of civilians are in danger of being massacred?" The Secretary-General has long experience on the peacekeeping side of the organisation and will doubtless be looking for practical recommendations and proposals to improve the organisation's performance on the ground.

One of the difficulties which needs to be addressed is the gap between aspiration and reality, between the fuss made over the approval of a peacekeeping project by the Security Council and the problems encountered in putting the plan into action.

Ways must be found to put pressure on member-states to supply, not just words, but the personnel and resources to implement them. Speed is of the essence, and the need for more rapid deployment of UN forces will have to be emphasised. Financing is a huge headache, and the arm's-length position of the United States in this regard remains an underlying problem.

In recent years there has been a new emphasis on the role of civilian police in addition to the traditional deployment of military forces. But difficult as it is to persuade nations to release their soldiers, there is even less eagerness to spare constables from the beat. Even in stable Ireland you never hear complaints about too many gardai looking after the physical welfare of the populace.

The peace panel, chaired by former Algerian foreign minister Lakhdar Brahimi, will have to come up with concrete recommendations to tackle this dilemma. The decline in traditional conflict can often mean a greater need for the pro-active skills and training of your neighbourhood constable than the more passive and deterrent attributes of the soldier on peacekeeping duties.

An old UN hand recalls how "the principle used to be that a peacekeeping force should have no enemies". This enviable position cannot always be achieved in a world where there is often no middle ground any more. One of the problems the peace operations panel will have to address is the need for UN peacekeepers to respond in a more vigorous fashion when they come under attack.

The report is not expected to address the thorny issue of regional military forces and their proper place within the overall UN context. This is already becoming a major theme in the debate on the future Irish role in peace operations, given the progress that is being made by the European Union towards setting up a rapid reaction force and the fact that the Irish contribution to that grouping - dedicated to peacekeeping, peacemaking and crisis management - could be as high as 1,000 troops. The debate will become more pointed if Ireland succeeds in its campaign for a seat on the UN Security Council.

The Brahimi report will be part of the preparations for the millennium summit at UN headquarters in New York on September 6th-8th, which will probably be the largest gathering of government leaders in history.

A similar event in 1995, to mark the 50th anniversary of the UN's foundation, yielded much in the way of rhetoric, but when the smoke and incense cleared there was little of practical consequence ("It turned into a talkfest," says one observer.) Perhaps for this reason Mr Annan has taken a very pragmatic approach to next month's deliberations, playing a central role in the preparations rather than leaving it to some bland committee.

Despite all the disillusion and cynicism over the UN's peacekeeping performance in the past 10 years, there seems no alternative but to take whatever practical measures are possible to reform and revitalise the organisation. There may be more efficient and streamlined vehicles on the road, but the UN is the only one in which everyone consents to travel.