Up to now, few have believed he could resort to such a drastic solution, since it would spell the end of his relations with the outside world and turn Serbia into a pariah state with little prospect of economic viability. In the past few days, however, the question has taken on a new urgency.
On Friday, Mr Milosevic made clear he was not interested, at least for the moment, in recognising opposition victories in last November's municipal elections. A letter sent in response to a damning report by the Organisation for Security and Co-operation in Europemade only the most grudging of concessions and denied the opposition its most significant prizes: control of Belgrade and Serbia's second city, Nis.
That suggests that the President and his cronies have decided to tough it out. But the protests have continued apace, making a mockery of the authority of both the President and his police force, which has watched the Belgrade marches passively from the sidelines.
Two weeks ago, the authorities restricted demonstrations to pedestrian streets in the city centre and yesterday suggested that all protests might be banned from next Sunday. The opposition has urged its supporters to thwart the police by clogging up the streets with cars - something they did to great effect last Sunday - and students have announced they will maintain their protests around the clock from Thursday.
Is the stage set for a showdown? "Milosevic will fight to the death and won't hesitate to use force to defend himself," said Dragan Veselinov, an opposition leader and professor of political science at Belgrade University. "He is ready to close the borders and turn the country into a concentration camp."
Professor Veselinov's opinion is shared, reluctantly, by many intellectuals who see the President as thriving on international isolation. The only thing holding him back, many believe, is a lack of money. Diplomatic sources say he has already been forced to withdraw capital stashed in foreign banks to pay the police and placate public-sector workers with some of their salary arrears.
Another consideration must be the strength of his fire- power - the real uncertainty. When the opposition launched big protests in March 1991, he sent in tanks and quickly brought the country to order, but this time that is not an option. The army has been worn down by the break-up of Yugoslavia, offended by the covert role it was asked to play in the war in Bosnia, and now deprived of the resources to pay its men or keep its equipment up to date.
As a result, roughly half the standing army is now with the demonstrators, and some units would be prepared to intervene against the government in the event of a crackdown. The only first-rate troops Mr Milosevic could call upon are under the control of Arkan, the gangster commander held responsible for some of the worst atrocities of the war, and the radical nationalist leader Vojislav Seselj.
But even their loyalty may be in doubt if the situation seems to be going the opposition's way - both have good reason not to antagonise a new ruling order and risk prosecution for their past activities.
The resource Mr Milosevic will be counting on is the special police force he has been building up as his personal republican guard. Nobody knows how many of these police there are, but they are well paid, well equipped and answerable to nobody but the President.
According to a major in the special air services, they have artillery rockets, tanks, armoured personnel carriers, anti-tank and anti-aircraft weapons. Since September, they have been trained as fighter pilots with helicopter gunships.
According to Professor Veselinov, any conflict would be short but brutal. "There would be a lot of murders, but the decisive question would be which side in the conflict the people considers to be the traitor," he said. And the best way to avoid an armed confrontation? "For the United Nations to send troops to protect Kosovo. That would be an unambiguous signal that Milosevic is no longer the master of his own destiny."
n A bomb pushed tension higher in Belgrade yesterday as hundreds of thousands of protesters brought the city centre to a standstill. The bomb went off in the compound of the headquarters of the Yugoslav United Left (JUL) party led by Mr Milosevic's wife Mirjana Markovic, a party source said. ReutersReuse content