I believe that most of terrorism does happen because the people behind it have some goals, not for funsies; so trying to fight the causes would be one thing to do. Obviously, that's difficult for many reasons, and making life more shit for everyone else is cheap and easy, and hence preferred.

But if the cause is "death to the West" or "from the river to the sea" or "India should not be secular" then it's a bit of a problem. How do you fight the cause?