The Western world has, over the last two decades, become very familiar with the culture of Islamic radicalism. It’s also become clear that not all Islamic radicals are the same. While all Islamic radicals share a desire to impose their religious beliefs on others (Moslem and non-Moslem alike), there is a wide range of fanaticism and addiction to detail. On the moderate end of the scale you have the Turkish Moslems who formed a political party based on moderate application of Islamic rules and customs. These Turkish Moslems have been ruling Turkey for over a decade and have done a good enough job to keep getting reelected. Many Turks fear that these Islamic activists will become radicalized and anti-democratic, but so far this has not happened. Moslems in many other countries would like to adopt this Turkish model, but so far that has proved difficult.
There is already a form of Islamic radicalism that seems moderate enough, and international enough, to allow for widespread use in democracies. That is the Islamic Brotherhood. Unfortunately the brotherhood has many factions and some of them are very radical and just barely tolerant of democracy. Worse yet, the first national election the Moslem Brotherhood has won has been in Egypt and the moderates and radicals in the brotherhood spend more time arguing with each other than in dealing with problems running Egypt.
Then you have the salafists. These are ultra conservative Islamic radicals who believe every Moslem must live strictly according to Islamic law. This includes hatred of non-Moslems and tolerance for using violence to convert these non-believers to Islam. This led to the growth of the jihadist movement, which believes living a conservative Islamic life is not enough. You have to force other Moslems to do the same and kill those that refuse. Same deal with non-Moslems, which causes problems when the kaffirs (non-Moslems) are smarter and more powerful than the righteous jihadists.
Because of all this religion-based radicalism, the War on Terror has morphed into the War Against Islamic Radicalism. This religious radicalism has always been around, for Islam was born as an aggressive movement that used violence and terror to expand. Past periods of conquest are regarded fondly by Moslems, who are still taught by their religious leaders and teachers that non-Moslems ("infidels") are inferior. The current enthusiasm for violence in the name of God has been building for over half a century. Historically, Islamic radicalism has flared up into mass bloodshed periodically, usually in response to corrupt governments, as a vain attempt to impose a religious solution on some social or political problem.
The current violence is international because of the availability of planet wide mass media (which needs a constant supply of headlines) and the fact that the Islamic world is awash in tyranny and economic backwardness. This is why the Arab Spring uprisings, and their desire to establish democracies, may do some permanent damage to the Islamic terrorism tradition. But the changes won't come as quickly as many hoped. The past has a huge influence on Islamic societies. For many, resistance to change is considered a religious obligation. Many Moslems consider democracy a poisonous Western invention. There is still a lot of affection for the clerical dictatorship of legend, a just and efficient government run by virtuous religious leaders. The legends are false and there are centuries of failed religious dictatorships to prove it. But this legend has become a core belief for many Moslems and will not be shaken by reality or the historical record.