The "Arab Spring" uprisings which began in early 2011, continue and are proving very expensive in terms of lives, property damage, and economic losses in general. These popular rebellions led to the fall of several long time dictatorships and a rush to reform (or give the appearance of such) by most other Arab governments.
All this was not without cost, and it isn't over (especially in Syria, Yemen, Bahrain, and Algeria). Over 125,000 have died so far and millions more were wounded, imprisoned, or driven from their homes. The financial cost, so far, has been nearly a trillion dollars. Most of that is the economic damage from shrinking GDP. The rest is destruction of buildings and possessions. The lost wages and reduced economic activity have been particularly difficult for populations that were poor to begin with. Egypt, Tunisia, Libya, Syria, Jordan, Lebanon, and Bahrain have suffered most from the unrest, losing up to a third of their GDP because of the Arab Spring economic disruption. Then there is the cost in cash for wealthier monarchies and dictatorships that have spent money (sometimes borrowed) to placate their restless populations. The money spent here is not all Arab. The Assad dictatorship of Syria has been kept afloat by billions of dollars in support from Iran and much smaller amounts from Russia. There has also been some unrest in non-Arab Moslem nations because of Arab Spring, and that has cost billions to deal with.
The "Arab Spring" created several unexpected popular uprisings against dictators and monarchs. Most sort-of succeeded (Tunisia, Egypt, Yemen, Libya), while others failed or never got going (Bahrain, Saudi Arabia, Kuwait, Algeria, Morocco, Lebanon) and Syria is not over, but the rebels are winning, despite Iranian intervention. None of these uprisings developed into a true war. The most violent, in Libya, was won by armed civilians assisted by NATO smart bombs and warships. Libya, like the other uprisings involving heavy combat, were a collection of dozens of separate battles over a large area.
The uprisings were mostly about corruption and the resulting widespread poverty and bad government. For that reason, the Saudi Arabian monarchy was able to buy its way out of an uprising. Yemen mutated into low level civil war, while Syria grew into a countrywide guerilla war. Egypt and Tunisia were over quickly but subsequent elections put Islamic conservatives in power.
In Egypt the military was able to maintain its corrupt grip on the economy. It's unclear how this will turn out because the Islamic and secular rebel groups are spending most of their time going after each other. Indeed, the biggest problem was that these dictatorships were not just the single dictator but rather the segment of the population that kept the dictator in power and were well rewarded for doing that. These privileged groups were not eager to flee or give up their wealth. The dictator's supporters are striving to retain or regain their power. The Old Order has substantial economic and political resources and is willing to use them to retain power and wealth.
This arrangement was common to all Moslem nations, not just the Arab ones. Islam has a particular fondness for preserving ancient practices and traditions. Not all Moslems agree with this but the most traditional believers have long relied on violence and terrorism to block social, political, and economic change. Thus, the Moslem nations tend to be quite poor and backward compared to the rest of the world.
The Arab Spring is part of another reform movement in that it is trying to address the root causes of poverty, corruption, and mismanagement that are so common in the Islamic world. Naturally, a lot of vested interests, both secular and religious, are resisting these changes.