klinton

nothing, but the terror treat is permanent.
if you dont want to be striked by sudden death that will finish all your plans, goals and pleasure in this life in one moment (gosh, and it wont be by slipping in the bathtub or getting hit by rock dropping from the building or choking on food which are way more probable ways to die than in terrorist attack), you must feel secure. and you have government to feel secure.
just trust us ! we are here to help you, fix all your problems and basically manage all your life...because we love control and power

but on a serious note: you cant get rid of terrorism or bandits - as long as the humanity will exist, there will be always some bad guys....the best method is to eradicate reasons why people become terrorists or murders...the rest of the bad guys that will be here regardless of anything (even if there will be no reasons to be bad ;-) - I'm pretty sure that they will be always well known to police ;-)