Muslims (esp. Western liberal) will tell you that concept of 'Jihad' is all about what is called the Major Jihad - the struggle to consciously develop self-control, betterment of the self and suppression of worldly desires or behaviour deemed haram. With practice over time this becomes a subconscious repression of self-esteem, and self-expression becomes an anathema for oneself and others around you. Expecting women to wear the burqa or the hijab is an example of this suppression of self-expression in practice.
Diego Gambetta and Steffen Hertog published a paper about eight years ago, back in October 2007, entitled the 'Engineers of Jihad' which examined in some depth the over-representation of engineering graduates within violent Islamist organisations. Their findings included the importance of the attraction that engineers have to certainty, binary black and white thinking, a dislike for the social chaos of plurality, a desire to find a neat all-encompassing solution, and to hold more conservative political and religious views. In MENA countries a family has to make significant sacrifices to send a member through university. Engineering degree-level coursework exposes them to modern engineering technology which is predominantly Western, and then when they graduate they are frequently faced with very few professional opportunities for employment locally, creating personal resentment. Combined with a deeply ingrained societal resentment of the West and Western values this tends to predispose them to religious radicalisation. Perhaps the Luddites of Jihad might be a better term since they are trying to drag society back to the Middle Ages.
So what we are witnessing then is something of a revolution or Reformation of Islam. This time we don't have Martin Luther and the printing press; this is a widespread reformation mainly taking place via modern communication media enabled via the Internet, smart phones, radio and television**. The pace of cultural change has perhaps moved up a gear from a imperceptible drift to a quick march - but social activists (with AK-47s, smartphones or both) are pushing it in different directions in different places and times. Much of Syria and Iraq has temporarily been marched back to the middle ages in many respects - but the Internet is still there (where ISIS haven't switched it off) allowing exchange of information and ideas. In essence this is a war of ideas (like most wars), played out at horrendous cost with peoples lives and destroying the infrastructure and wealth of nations. This time the fight is about what Islam means. We need to reinterpret what it means to be a Muslim.
This is fight that cannot be won with bullets and bombs. Ideas live in peoples heads; they are transmitted or replicated via word of mouth, documents, rituals, videos, Tweets, etc. You can kill people but the ideas live on. Killing tends to generate martyrs, resentment and invite retribution long after the event. Like Goethe's Sorcerers Apprentice (1797). Take up an axe to destroy the broomsticks and each one you break will generate two more active broomsticks. It is only by reciting the right words that you can end the nightmare.
And briefly returning to the contribution of self-esteem to the radicalisation issue. To clarify the incongruity between real self-esteem and religion, because some people seem to have difficulty with this concept, I quote below from Nathaniel Branden (7 Hours Live. Tape 2 at ~34 mins):
"Of the types of neurotic solutions opted for by many people (and these are not mutually exclusive) one of the most important and often deadly types of substitute self-esteem that people can opt for is what I call self-esteem via identification; social or personal identification.
Social identification means identification of oneself with a movement, a cause, with an organisation, with some greater than myself institution. And from identification with, association with this particular movement, cause, club, group, religion, I derive my personal glory. This is obviously what attracts many people to religion and others to certain types of political movements. This is often the psychology of the True Believer. So by identification with some institution, some structure, some organisation, something larger than myself, I am good, my life has moral meaning, I have significance, I have glory, because I am part of this thing.
Now one of the reasons why this particular type of neurotic self-esteem solution is so socially dangerous and why its probably responsible for more suffering in human history than any other, is the fact that in order to derive my self-esteem from identification with some impersonal abstraction such as a cause, I have to depersonalise myself. I have to make myself an un-person to myself, and when I do that, other people cease to be persons to me and that makes it psychologically much easier for me to kill them, to torture them and to exercise every kind of brutality upon them in the name of this higher abstraction, and to commit atrocities which I could never commit if I thought I was doing this selfishly, in my own name and for my own sake. Once I disappear into this immense personal abstraction, so do you, and so do all human beings, and then we see the kind of atrocities that enter into the history books. The depersonalisation, first of self and then of others - that is the irresistible consequence of identifying personal worth with identification in some kind of abstract cause or movement".The quote above is taken from recordings of public lectures by Branden which you can find online, but to my knowledge he didn't include anything quite so explicitly anti-religious in his published books. I guess his editor advised him that America in the 1970s was not yet ready for the truth.
** For a more extensive analysis of the impact of technology on Islam and Christianity over time, please read The Bishop, the Mullah and the Smartphone by Bryan Winters. I personally had some input into this and recommend it to you.