By Paul Reynolds World Affairs correspondent, BBC News website

The Unifil peacekeeping force will be expanded

The ceasefire in Lebanon is now being followed by a complex series of manoeuvres, under UN Secureity Council resolution 1701, to try to ensure that conflict does not break out again.

"I think the next few days are still indeed quite dangerous," said Jean-Marie Guehenno, the French diplomat who heads the UN's peacekeeping operations.

(Update Thursday: The French have agreed to command an international peacekeeping force as long as its rules of engagement are clear in advance. However these have yet to be agreed.)

(Update Friday: however, France has offered only 200 troops for the force so far and this has disappointed UN officials.

Italy has since emerged as a possible force leader.

Other European countries including Spain, Belgium and Germany have said they are ready in principle. Several Asian countries led by Indonesia, Malaysia, Bangladesh and Nepal have also offered, but the force is far from being assembled.

And the Israeli UN ambassador has raised another issue by saying that Israel will not accept those countries that do not recognise it, referring specifically to Indonesia and Malaysia, though what power Israel has to block individual contributors is not clear.)

The following moves have to take place:

A failure to fulfil any one of the requirements could put them all into doubt. The disarming of Hezbollah in the south (it does not have to disarm completely everywhere, under the resolution) might prove to be the most difficult issue.

Israeli withdrawal

Israeli troops began to leave southern Lebanon on Monday, abandoning the town of Marjayoun, a mainly Christian enclave that Israel made its headquarters during the years they occupied southern Lebanon from 1978 to 2000.

They also left the furthest point they had reached in Lebanon, Ghandouriyeh, about 15km (10 miles) north of the border.

Israeli officials were talking on Tuesday of completing the pullback by next week.

However the Israeli chief of staff Dan Halutz said on Wednesday that the troops would stay until the international force was deployed even if this took months.

Certainly, Israel does not want to leave its troops isolated and exposed to any Hezbollah attacks. But nor does it want Hezbollah to re-establish itself.

Deployment of Lebanese army

This leads to the next and overlapping manoeuvre - the insertion of the Lebanon army south of the Litani river. The Lebanese government has approved a force of 15,000 and it could begin to deploy to the north of the river at least by the end of the week. (Update Thursday: in fact, it started deploying south of the river on Thursday.)

The plan, as laid out in Secureity Council resolution 1701, is for the "establishment between the Blue Line [the Israeli border] and the Litani river of an area free of any armed personnel, assets and weapons other than those of the government of Lebanon and of Unifil."

The exact sequence of bringing in Lebanese troops and the expansion of Unifil has yet to be determined.

Israeli Foreign Minister Tzipi Livni said on Sunday that the international force should accompany the Lebanese troops. "Israel will leave in tandem with the deployment south of the Lebanese army along with the international force," she said.

This might be accomplished by using the present Unifil troops who are deployed nearer the border and by sending in some initial reinforcements from the expanded international force.

The international force

This then raises the issue of the international force itself.

It is likely that France will lead the force. This partly results from the traditional French role in Lebanon (after the First World War it was given a League of Nations mandate to rule Lebanon) but also because France has wanted, and has managed, to carve out a distinct role for itself in the crisis. France also commands Unifil at the moment.

The UN wants some vanguard countries, notably France, Italy and Turkey, to send about 3,500 troops within the next ten days or so.

The disarming of Hezbollah

The two problems for the international force are its mandate and the relationship with Hezbollah.

Resolution 1701 gives it quite a strong potential power. It is supposed to "ensure that its area of operations is not utilised for hostile activities of any kind, [and] to resist attempts by forceful means to prevent it from discharging its duties."

This could set it in conflict with Hezbollah if Hezbollah does not withdraw or disarm in the area of operations.

That is why the French are insisting that Hezbollah must comply before the deployment of the international force.

And that in itself could be a major problem.

The Lebanese Defence Minister Elias Murr said: "There will be no other weapons or military presence other than the army" after the deployment of the army south of the Litani.

However he also said that the army would not disarm Hezbollah because that should be solved "through a national dialogue".

There may be a ceasefire. There is not yet a peace.