When European, at first Christian and then secular colonial powers run rampant over your culture and people for 100+ years, and demonize your local majority religion as barbaric for almost as long, practicing that religion becomes an act of anti-colonial resistance in and of itself. A way of rejecting outsiders' attempts to define "correct" beliefs and morality on their own terms.

Then there's also the element of practicality. At least in Palestine and Lebanon, a lot of the secular leftist anti-colonial movements have been hollowed out, smothered and/or discredited over the past several decades, leaving more religious groups like Hamas and Hezb Allah as really the only resistance-capable game in town.

Also also, there's a social element to it. Class differences can sometimes feel abstract, and religion, like race or narionality, offers a way to cut through that abstraction. A clear way of differentiating colonized in-group from colonizer out-group.

this is like asking why people get into religion generally, the flavor of religion seems to be fairly irrelevant for it becoming a murder-justification. i won't speculate or pontificate on 'why religion' because i'm irreligious

materially, Wahhabists are successful in radicalizing people because their preachers & groups are backed by Saudi Arabia & the CIA, but it's not like they invented the concept of murder + martyrdom

Step 1 is usually the West fucking a place up, while justifying it with Western moral sensibilities (cynically, they don't actually care and are there to steal resources/get cheap labor, eg British politicians/generals opposing eg women's suffrage at home while banning hijabs etc)

Violent resistance to that or Western intelligence financing radicals often follows (either organic because of the scale of the violence, or occupiers purposefully seeking to prolong the security crisis/justify further "investment" of military resources).

Why the fuck were there so many euro teens falling for fukcing ISIS groomers in the 2010's?

Blowback season 4 has great coverage on how the US propped up far right Islamic movements, leading to the Taliban among other groups. These movements aren’t often organic in origin. People aren’t naturally predisposed toward this path. So much of it has been directed and supported by foreign powers for their ambitions.

I'd recommend the book Engineers of Jihad. It's precisely the people who wish to change the world and then are denied by external forces (largely the U.S. in this case) that are primed for radicalization.

Also iirc, Bashar al-Assad's father was the one who actually developed the tactic/justification but I'm having trouble finding a source, it's early.

no sex, live by the book (Das Kapital), ~~behead~~ guillotine those who disagree

Checkmate Tankies

One big reason is that the Saudis fund it. They're not the only ones - a plurality of the weapons that have flowed into the middle east have specifically gone to the most radical religious extremists because those groups tend to also attack socialists, arab nationalists, African unity types, and others that oppose the global economic order.

For similar reasons the other vile reactionary ideologies in the west attract people, I'd say

I get why people become radicals of other kinds...

So you can understand Hindutva radicals, nazi radicals, Tamil tigers, but not Islamic fundamentalism?

Seems like a very weird non sequitir

Depends on the region, but mostly it's a combination of imperialism and Saudi funded madrassas, one gives you reactionary ideas and the other makes you believe the ideas are true, also it's used a tool for western imperialism directly or indirectly. For example when you look at ISIS, Abu Bakr Al-Baghdadi was in Abu Gharib at some point, and a lot of the ISIS recruits were from poor parts of the world that had a lot of Saudi "schools" built in them, with the recent attack in Moscow the guys were Tajiks which was formerly a USSR state.

but saying no music, no sex, live by the book, behead those who disagree... what part of that makes people think "I want to get into this, this sounds fun"?

The promise that they'll be rewarded for their efforts in the end goal of a khilafa or in the afterlife... and who told you they don't have sex? you think they kidnap women just to play minecraft with them or something?

Others have given good reasons, but many people join very strict religious orders in other religions. And some of those have been very militant.

It's easy to get people to hate The West, and their own governments, and the increasing alienation of their lives as capitalism elides all cultural social bonds. That's the same thing that leads to what Marx called "reactionary socialism", the urge to retvrn to a rural ideal that is no longer materially possible.

It's also easy to get people to accept an ascetic religious life. Regular rituals, fellowship of others and discussion, a simple life, without the distractions and mistakes and disappointments of real life. Its just the more systemised version of the urge to go live in a yurt in Mongolia after a bad breakup or when you've fucked up particularly hard.

Combine them. Have the material fire of reactionary/agrarian social tendencies, and feed it with the superstructure of monastic mysticism, but without the disengagement with the world. And you have a radical.

All the book burning and misogyny is (mostly) either bolt-ons or hold outs of the collapsed reactionary ideology

I get why people become radicals of other kinds... but saying no music, no sex, live by the book, behead those who disagree... what part of that makes people think "I want to get into this, this sounds fun"?

I don't think many true radicals do it because it "sounds fun" perhaps you're confusing your ability to empathise with non-muslim radicals with actually understanding them?

There's a book, engineers of Jihad, that noticed that engineers are statistically more likely to join islamic terrorists orgs than other people.