
This Arab Spring has been uncannily like the Japanese earthquake and tsunami, only this one's entirely made by humans. Like continental plates grinding against each other, tensions that can't go on forever have been going on way too long. Once they shift, the energies released are as implacable and unstoppable as a tsunami. Mass movement is scary, more like a force of nature than a volitional act.
Volitional acts do matter, though. In both natural disasters and manmade ones.
Revolutionary situations expose the faultlines usually hiding beneath the surface of a political superstructure. While the unrest of the Arab Spring has spread in ever wider circles, events in the countries where it has broken out have followed rather distinct trajectories. While situations like these are extremely fluid and anything but deterministic, a good deal of what's going on is explicable by the hidden faultlines within the societies now coming to the surface.