The nickname of Jarhead is not miskaten.
That's not even a very good insult. Jarhead is not a nickname for the Army.
As far as... Well, everything above...
Islam is obviously not "just a violent religion". The
vast majority of Muslims are regular people, just like everyone else. The fanatics are just a tiny fraction. The same holds true of Christianity and Judaism. There are absolutely crazy, violent minorities of both of those religions as well.
It is authoritarianism, not particular religions, that is dangerous. People have the absolute right to believe whatever wacky things they want, traditional or not, so long as they don't become so enthralled with their beliefs that they believe it is their mission to impose this belief-system on the rest of the world via force if necessary. Fundamentalist sects seem to be the most authoritarian, at least in the modern era, though all three of these major religions are authoritarian to one degree or another (okay, not Unitarian Universalists, but you can only kinda call them Christians).
Add to that a healthy dose of us and our allies (and foes) screwing with the region for fifty or sixty years throughout WWII, the aftermath, and the Cold War. Add a dose of poverty, and rule by brutal, authoritarian regimes (which they blame, not totally unjustly, on us). Add to that eons of religious-based bad-blood. Then, sprinkle on a crapload of money.
This is what you get.
I firmly believe that if the situation was reversed, and Saudi Arabia and Iran were running the world (and had been fighting their own proxy wars for decades) and the US was a largely isolated, poor, minor power ruled by despots? There'd be people here strapping bombs to their chests too. Probably in the name of God.
But, this is the situation we live in. It makes me sad. But, honestly?
The world is a dangerous place. It has always been a dangerous place, and always will be. With progress comes the ability to murder and torture one another in new and creative ways. But that too, is nothing new. All you have to do is look at history, and you can see it going back
all the way through. Is it worse now? I don't know. It is more likely that we'll do something to destroy the entire planet, or wipe out the entire species. But on an everyday crime to everyday people level (wars included)? I'd say we're actually doing pretty well, looked at historically.
When I was a kid, the homicide rate was
roughly double what it is now.
When I was a kid, it was okay to beat up people who were gay, as long as you didn't do it in school.
When my father was a kid, Joseph Stalin was killing people by the millions in the Soviet Union, the partition of India happened, and Chiang Kai-shek ruled China.
When my grandfather was a kid, we were killing people by the millions in World War II, Vladimir Lenin had his Red Terror, and the partition of Palestine happened.
When his grandfather was a kid, we were killing people by the tens of millions, in holes, in World War I, and the British were conquering Palestine.
All the way back to Napoleon, Ivan IV, the Crusades, the Inquisition, Ghenghis Khan, and Emperors Nero and Caligula, and surely countless horrors unrecorded by history. All the way back to living in the plains hunting each other with sticks.
One big difference? We have a much, much, much bigger media microphone, and we hear about everything now, from all over the globe. Instantly. And people make money by making it as extravagant and scary as is possible. That's not to say that we don't live in dangerous times. Only that this is not a unique human condition.
I give us moderate odds at not exterminating ourselves by some means or another.