We by that I mean in the west, only see a small fraction of this particular terrorism. People in-situ see much more and are escaping and risking their lives to escape because it's so devastating.

Doing nothing would mean leaving the whole country to go down the drain with multiple generations scarred by war, atrocities, tribalism, lawlessness, etc. That's why advanced countries typically go in and try to tamp things out, sometimes the results are less than desirable, but doing nothing surely seals their fate --as it does to many countries in Africa (where international African forces nominally are in charge, but typically do little, are ineffective, corrupt)

Yes, my response was about terrorism in the West. What happens in the East is closer to a civil war.

If you by "in the West" you mean domestic western terrorism... maybe. Still, in the US the FBI and other gov't agencies monitor those orgs because of the potential to escalate into an undesirable state.

If you mean middle eastern terrorism jumping over into the west, I think it's fair to say that if they could, they would strike, but the threat has been managed well with the security precautions in place, but that's not to say they aren't trying to overcome their shortcomings.

Isn't death collateral damage in just about every conflict? People usually just want power.

True, but in a typical conflict you attack enemy warriors and infrastructure in order to deny them the power to do the same to you. Since you can't hope to convince them to not attack you, you have to kill them. If a general orders you to strike a facility, their direct goal is to have that facility - and its contribution to the enemy war effort - eliminated. Terrorism, on the other hand, is about provoking the enemy into action. Victims are completely unrelated to the goals attackers may have.