I think terrorism will never end, because there are two kind of terrorist. the first one is some one is really bad guy and make a terror, I think this kind of terrorist could be stopped. the second one is some political conspiracy who create a terrorist to gain benefit from the chaos situation, I think this kind of terrorism not easily being eliminated. the second kind of terrorism is the majority one.
The result of both is the same. If other countries could do something to at least suppress them, then everyone could. Two things, it's either you fight them or you negotiate with them and eliminate them little by little.
Now, terrorists have a reason, they don't just kill or terrorize people because they want to, but mostly it is political, they have some grudges to the government that can't be solved and fueled by politicians who will use the emotions of the leaders of these terrorists then there you go.