OXFORD, ENGLAND — Even as the mass demonstrations began in Tunisia, who would have thought that Zine el-Abidine Ben Ali’s regime would have collapsed so quickly? Who could have predicted that Egypt would soon witness such unprecedented popular protest? A barrier has fallen. Nothing will be the same again. It is quite likely that other countries will follow the lead of Egypt, given its central and symbolic significance. But what will be the role of the Islamists after the collapse of the dictatorships?