CHRIS FISHER, EDP Political Editor Having passed the resolution that led to Monday's fragile ceasefire in Lebanon, the UN lost little time in plunging into wrangling about implementing it.

CHRIS FISHER, EDP Political Editor

Having passed the resolution that led to Monday's fragile ceasefire in Lebanon, the UN lost little time in plunging into wrangling about implementing it.

The resolution authorised the deployment of a UN peacekeeping force of up to 15,000 to work alongside Lebanese troops of up to the same strength to establish and maintain a buffer zone south of the Litani river in the territory that had effectively come under the rule of Hezbollah.

But who is going to supply the extra UN troops? It had been supposed that the French government, which has been very busy trying to establish a lead role in this operation, would supply a substantial proportion of them. So there was much surprise and consternation this week when it said it would initially despatch only 200 new troops.

It will no doubt be prepared eventually to send many more than that. But it looks as if it will expect other countries to provide the main bulk of the force. Which countries? Can enough forces be found from nations that are acceptable to both sides? And can an increased UN presence be significantly more effective than the existing one, 2000-strong, that failed so lamentably to keep the peace?

Much depends on what they will be allowed to do. Specifically, will they be authorised to confront and disarm Hezbollah? There is much uncertainty and ambiguity on this point. Will the French, with their long-established interests in Lebanon, really be prepared to have a showdown with the Islamist militia that seems to have become the main player in Lebanese politics? Will and should the Israelis expect anything less in exchange for pulling forces back?

Will the new security-council resolution, 1701, prove as toothless as its predecessors, 1559 (passed in 2004) and 1680 (this year), that demanded the disarmament of all armed groups, including Hezbollah, in Lebanon? It too calls for such disarmament, so that "there will be no weapons or authority in Lebanon other than that of the Leban-ese state". But how is this to be done? If, moreover, it is not implemented, how can the ceasefire hold?

This is hardly, of course, an unfamiliar story with the UN. Some would say it is the essential story of the UN - one of passing resolutions that are ignored. And one of the strongest examples of that phenomenon, resolution 452, lies right at the heart of the ongoing crisis in the Middle East. Passed by the security council in 1979 - with the US abstaining - it called upon "the government and people of Israel to cease, on an urgent basis, the establishment, construction and planning of settlements in the Arab territories occupied since 1967, including Jerusalem".

But that very plainly did not happen. The building of Israeli settlements on the West Bank and in Gaza went on and on, and the UN, largely due to the underlying support of the US for Israel, could not do anything.

There have been many other examples of UN impotence, and the most glaring ones include the failures to stop the genocide in Rwanda in 1994 and in Bosnia in the mid-1990s. And the weakness of the UN was also highlighted in the months leading to the start of the Iraq war in March 2003.

The most committed opponents of Tony Blair's decision to join the US in going to war maintain both that it was illegal and without the authority of the UN. The prime minister and those who supported him argue virtually the opposite. They concede that - because of the failure to get the second resolution - UN authority was not as explicit as they wanted. But they are adamant that sufficient authorisation came from security-council resolutions 1441, 687 and 678. Resolution 1441 was approved unanimously, 15-0 in November 2002. Russia, China, France and even Syria backed it though it was clearly couched in 'last chance' terms. Iraq was given "a final opportunity" to comply with its disarmament obligations and told there would be "serious consequences" if it did not co-operate "immediately, unconditionally and actively" with weapons inspectors.

Maybe there was a feeling among some parties that this was yet another resolution that was 'all talk and no do' and that nothing would come of it. When it became impossible to avoid the conclusion that the US and British governments really did mean it, they were completely blocked at the UN. The coveted second resolution was scuppered, largely on the initiative of the French. It was plainly understood that if such a resolution were forced to a vote, it would be vetoed by the French government. The possession of a veto power by the five permanent members of the security council is the main structural reason for the UN's reputation for paralysis and inertia.

The interest of these countries can be very different, and there are bound to many occasions when it will be impossible to get them on the same side in the security council. It is virtually inconceivable, moreover, that any of them will ever agree to surrender its veto. The US is not going to hand over the ultimate decision on matters of its national security to the UN. Neither is China, Russia, France or, indeed, this country.

There is a difference, however, between failing to agree a resolution and refusing to allow the implementation of what has been agreed. Let's see what resolution 1701 is made of. Let's hope it's not just hot air again.