I'm not sure how I feel about the tone of this article - it's a particularly unsympathetic portrait of two american "losers" that ended up joining al-Shabaab and ISIS. However, it's worth reading if only because it perfectly matches what I know about the recruitment methods of Hamas.
Al Qaeda has more in common with Rastafarianism than it does with the Irish Republican Army. A sense of belonging counts more than a sense of mission; a philosophy more than a battle plan. I don't know how many young Americans are likely to rush to Kurdistan for Allah but I do know that every terrorist you've ever seen on TV grew up disaffected on the fringes of Western culture.