Idle contemplation of the methods of radical Islam leads to the following thoughts:
1.) Any ideology that relies on violent coersion for acceptance lacks the underlying truths to endure. If the radical Islamists must appeal to fear and intimidation, it is because they cannot rely on the spiritual and universal truths that are inherent in more successful movements. Islamists should look to their own history for inspiration. The mongols regularly routed Muslim armies. They traversed Persia and central asia at will, yet the fundamental truths of Islam converted the conquerors. It is these truths that the radical Islamists have lost.
2.) The mehtods of radical Islam are pretty hopeless. Their repertoir consists solely of spectacular explosions. It would appear that no one supporting the radical's aims has thought that this is a poor foundation for an empire. Presumably, the radicals think that terror bombings will force enough concessions to allow them to engage in more effectrive means of intimidation. Hamas' experience with Isreal should disabuse them of this notion. If the methods of radical Islam can't even succeed against a small, politically isolated country with limited resources, they have little chance of spreading the faith world-wide. Frankly, the fact that some disaffected idealists are willing to blow themselves up is neither terrifying, novel, nor impressive. Suicide cults are as old as civilization. Suicide missions in warfare have a long and storied history independent of jihadist mythology.
3.) The jihadist tactic of indiscriminant suicide bombing lacks any sort of appeal to legitimacy. Even if one were to assume that Islam condoned such behavior, the religious contradictions involved are too much to overcome. Assume that a suicide bomber kills a seven month old girl. This victim is obviously innocent, lacking any capacity to infidelity or wicked behavior. Moreover, she would be regarded as a creation of God, the God of Abraham that is supposed to unite Christian, Muslim and Jewish traditions. There is no excuse for the indiscriminant killing of a child of God. Such a suicide bombing can only be seen as a grave transgression. (This does not even consider the possibility that the child might be a Muslim.)
4.) Many of the jihadist leaders are not so much religious zealots ans they are revolutionaries. Zarkawi has more in common with Che Guevarra or the conspirators that assassinated Czar Nicholas II than they do with any of the learned teachers of Islam. There is more anarchy than theology to their thought. Despite the Koranic convolutions, they are opposed to governmental power and perpetual "struggle" moreso than Islamic thought. If Al Zawahiri had been born in the 1920's he would have been a communist, in the 1870's, an anarchist. There is nothing spiritually religious about these people.
5.) The defining feature of jihadist thought is chauvinism. They believe they are special because they are willing to die for their cause or be inhumanly brutal. Other societies have done this much better than the modern radical, but predictably, such characteristics lead to the demise, rather than the flowering of the culures that embraced them.