OF ALL the Arab regimes, Tunisia's seemed like the least likely to succumb to "people's power". But that the Arab world has now seen the popular overthrow of an autocratic government is not entirely surprising. One of the last big things I wrote for The Economist before coming to America as "Lexington" was a special report on the Arab world, which came to the conclusion that beneath the apparent political stagnation a social revolution was already under way. The report, "Waking From Its Sleep", appeared in July 2009, and my accompanying editorial concluded:

Behind the political stagnation of the Arab world a great social upheaval is under way, with far-reaching consequences. In almost every Arab country, fertility is in decline, more people, especially women, are becoming educated, and businessmen want a bigger say in economies dominated by the state. Above all, a revolution in satellite television has broken the spell of the state-run media and created a public that wants the rulers to explain and justify themselves as never before. On their own, none of these changes seems big enough to prompt a revolution. But taken together they are creating a great agitation under the surface. The old pattern of Arab government—corrupt, opaque and authoritarian—has failed on every level and does not deserve to survive. At some point it will almost certainly collapse. The great unknown is when.

That the authoritarian Arab governments are vulnerable and unpopular is easy enough to see. The hard thing to work out is what might take their place. Although it is sometimes assumed that political Islam will thrust itself into the space vacated by secular authoritarians, the appeal of Islamism in most Arab countries has a ceiling, which well-informed analysts in 2009 put at around 20% of the population. Besides, one great prop of the existing regimes (beyond their control of the army and secret police) is that in almost all Arab countries opposition is divided between the secular liberals on one side and Islamists on the other. The Islamists hold the secular liberals in contempt and the secular liberals are afraid that if the Islamists take power it will be "one man, one vote, one time". So the opposition has checkmated itself.

Because the Islamists are relatively weak in Tunisia, it is not clear that what happens as elections for a new government get under way will reveal much about the direction or timing of change elsewhere. If the upshot in Tunisia is violence and chaos, the Tunisian uprising might even retard change in the other countries -- much as the mayhem after the invasion of Iraq in 2003 gave the notion of American-imposed democracy a bad name. Nonetheless, this will have been a disturbing week for dictators, kings and emirs throughout the Arab world. The idea that Arabs are passive or docile has been thoroughly discredited. And what will take the place of such regimes if they collapse remains anyone's guess.