Is it a real revolution in Tunisia or will another member of the ruling elite succeed in replacing President Zine el-Abidine Ben Ali who took flight yesterday?
It is a crucial question for the rest of the Arab world where other corrupt police states face the same political, social and economic problems as Tunisia.
A striking feature of the whole Middle East for more than 30 years has been the unpopularity of the regimes combined with their depressing ability to stay in power. Most have found ways of preventing revolutions or military coup d'etats through ferocious security services protecting rickety state machines that mainly function as a source of jobs and patronage.
In Tunisia, Mr Ben Ali, along with other Arab leaders, presented himself as an opponent of Muslim fundamentalism and therefore won tolerance if not plaudits in Western capitals.
But the revolution that is brewing across the Middle East is of a traditional model springing from high unemployment, particularly among better educated young men, and a ruling class unable to resolve any of their countries' economic problems. The most obvious parallel with Tunisia is Egypt where the sclerotic regime of President Hosni Mubarak clings to power.
Will the present so-called "soft coup" work whereby Prime Minister Mohamed Ghannouchi takes power and calms down protesters by promises of reform and elections? It does not look very likely. The declared State of Emergency is not working. There is not reason to suppose that a political leader so closely associated with the old regime will have any credibility with people in the streets.
Conditions vary across the Arab world but there is plenty in common between the situation in Tunisia and that in Algeria, Jordan and Egypt. Economic and political stagnation is decades old. In some states this is made more tolerable by access to oil revenues, but even this is not enough to provide jobs for educated youths who see their path blocked by a corrupt elite.
There are echoes of the Tunisian crisis in other countries. In Jordan the security forces have been battling rioters in Maan, a traditional site of unrest in the past where the government has difficulty coping. In Kuwait there was an attack by security forces in December on academic and members of parliament. Food prices have been going up.
Yet all these regimes that are now in trouble had a carefully cultivated image in the west of being "moderate" and anti-fundamentalist. In the aftermath of the invasion of Iraq, President George Bush and Tony Blair made much of their democratic agenda for the Middle East, but when one of the few democratic elections to take place in the region produced victory for Hamas among the Palestinians of Gaza and the West Bank, the US did everything to thwart the outcome of the poll.
The Middle East still has a reputation for coups but a striking feature of the region since the early 1970s is how few of the regimes have changed. The forces behind the Tunisian events are not radically new but they are all the more potent for being so long suppressed.
Western governments have been caught on the hop because explosions of social and economic frustration have been long predicted but have never happened. The extent of the uprising is yet to be defined and the Tunisian army evidently hopes that the departure of Mr Ben Ali may be enough for the government to restore its authority. The generals could be right, but the shootings over the last month failed to work. There is no particular reason why the same tactics should start to work now.