Nato's foreign ministers last week instructed Nato staff to speed up contingency planning for the possible deployment of a multinational contingent on Albania's and Macedonia's borders with Kosovo.

The purpose of such a deployment would be to seal off Kosovo and thereby prevent the conflict from spilling over the borders.

According to current plans, the Nato force would need up to 23,000 soldiers to provide an effective cordone sanitaire around Kosovo.

That would almost certainly be able to stop any incursions across the border by regular forces.

Guerrilla, refugee movements

It is less likely, though, that it could completely eliminate movement across the borders by small groups of Kosovar Albanian guerrillas - and if it did, it would certainly help the Serbian forces by depriving the ethnic Albanians of reinforcements.

But no military deployment could halt the flood of refugees which - if it were to start on a large scale - might seriously destabilise both Albania and Macedonia.

For the moment, though, Nato is concentrating on plans to work out the logistics of troop deployment.