Justified is a part of life, dude. It's not just words that I want to use. There's millions of people in prisons based upon the word 'justified.' And if the 'extremists' actions are not justified and their actions are 'extreme,' then you can't come back and say 'well, you had it coming.' I'm sorry, but that's just not how life works.
Every one of those people in prison felt they were justified in doing what they did.
Yes, when you arm crazy people for bad reasons, you should expect consequences.
And the biker bar analogy; crap. Geo politics is not a biker bar. It's the big leagues. Anybody engaging in terrorist attacks ain't in our league.
Actually, the one historic truth about "Terrorism" is eventually, the Terrorists win.
Eventually, you just get tired of dealing with them. Eventually, we pulled out of Iraq and Afghanistan. Eventually, the British pulled out of Ireland. Eventually, we pulled out of vietnam in 1973.