I dont believe the world will ever be free of terror, and all we can try and do is strike terror down when it arises and keep the factions from growing and taking over countries. The groups need to be brought down in size and maintained. but i believe terrorism will always exist in some form
The world will never be free of radical ideas, therefore it will never be free of terror. The best we can do to stop terror is to set the precedent of "this is what happens to you if you terrorize someone or something." I don't think it's a great response to terror, but for now it seems to be our best option.
When a terrorist group forms, they provide their forces with young and often uneducated civilians. I believe education would stop enormous amounts of people from joining, or being forced into these groups.
We can stop groups and we can stop people, but you can't "stop" an ideology or idea. We can destroy ISIS/ISL/IS or what ever the heck you want to call them. We can kill terrorists. We can lessen their influence on impressionable muslim youth. However, the important thing in this war it to do what you can, while striving for what may be impossible.