Arab revolutions have not failed, at least not yet. It will take us years, or maybe even an entire generation to assess their failures or successes. They have "failed" according to our hyped expectations and erroneous understanding of history. What popular revolutions do is that they introduce new factors that challenge the way countries are ruled. 

In post-colonial Middle East, Arab countries were ruled through dictators - and their local associates - and foreign powers. The harmony and clashes between the dictator and the foreigner determined the course of events in most Arab countries - in fact in most post-colonial experiences around the world. 

This is where the real significance of the mass mobilizations in Arab countries becomes very important, for the "people" - a factor that is still far from having been fully defined - challenged the rules of the game and mixed up the cards. True, they sent the entire region into disarray, but it is the price one would expect to pay when powerful regimes and foreign powers are challenged by long-disempowered, disorganized and oppressed people.