"The street revolutions that ended communism followed similar patterns because they followed in the wake of a single political event: the abrupt withdrawal of Soviet support for the local dictator.
The Arab revolutions, by contrast, are the product of multiple changes - economic, technological, demographic - and have taken on a distinctly different flavor and meaning in each country. In that sense, they resemble 1848 far more than 1989."
A good thumbnail history lesson
by Anne Applebaum of the WaPo. Although, her minimizing the role of radical Islam in this mix is troubling.