Ten days after the start of air strikes on Yugoslavia, Nato has for the first time hit targets in the centre of Belgrade.

The Alliance admits progress in its air campaign has been slow, partly because of bad weather, but the suffering of Kosovo Albanians has become immeasurably worse during that time - Nato says that at the present rate, Kosovo would be emptied in 10-20 days.

Although Nato is hugely superior in military terms, it is hampered by relying purely on air power and - despite the attacks on Interior Ministry buildings in the centre of Belgrade - by the need to minimise civilian casualties.

President Milosevic appears to observe few or no restraints on the conduct of his operation to drive Kosovo Albanians from their homes.

Took advantage

Nato has repeatedly denied that the air strikes were the cause, or the catalyst, of ethnic cleansing. But Mr Milosevic certainly took advantage of them to accelerate the terror and the expulsions. Nobody in the West foresaw the scale of this operation; nobody imagined there might be an attempt to expel up to 90% of Kosovo's population.

Albanian and Kosovo supporters of the air strikes in London

From the Yugoslav leader's point of view, the destabilisation of neighbouring countries like Albania and Macedonia can also be counted a success: it weakens them and adds to the problems of the West, which to some may appear to be responsible.

Hardened resolve

On the other hand, the terrible suffering of the Kosovo Albanians has so far hardened western government resolve and public opinion against Belgrade. Dissent within Nato has been muted. Opinion polls show solid support for the air strikes in the big member countries, with the exception of Italy. Doubts are more pronounced in southern Europe.

Liberal opinion in the West is generally in favour of what it perceives as a just war, which has not been the case recently with military action against Iraq.

Western politicians who were radical or left-wing peace campaigners in their younger days - like the German Foreign Minister, Joschka Fischer, and the British Foreign Secretary, Robin Cook - are now pursuing the military strategy.

Ground troops

The main criticism in the West of the air strikes has been that they are not effective. Television pictures of miserable refugees have swelled the numbers of those demanding the intervention of ground troops.

There are now discussions going on about a possible role for Nato soldiers in protecting ethnic Albanians inside Kosovo, though an invasion against Serb resistance is still ruled out.

Anti air strike protestors in Bucharest

Day after day, Nato spokesmen have had to report that bad weather has largely prevented direct attacks on Serb combat forces inside Kosovo, while insisting that Belgrade's military capabilities are being steadily reduced. This situation may change: the message is that given time the damage will accumulate and accelerate.

However, Mr Milosevic may not give Nato the time it needs. With much of the population evicted from Kosovo, some observers believe he will at some point make an overture to the West which it will find it difficult to reject. That was not the case with the offer conveyed through the Russians.

But if Mr Milosevic were actually to stop his offensive and withdraw some forces from Kosovo, Nato would be in a dilemma. To stop the bombing then would leave the Serbs in control, the Kosovo Albanians homeless - and still no agreement by Belgrade to the deployment of an international military force as part of the international peace plan.