When John Kerry said that terrorism must be reduced to a nuisance level, what he was really saying, IMO, is that preventing terrorism inside the U.S. is really a police action like preventing any other crimes. If you are going to do it successfully, you must have the proper institutions and laws in place. Let me try a parable.
You are on a boat floating in an ocean of people that do not like you. As long as the boat's hull is intact, you are safe. All of a sudden, you discover a leak in the boats protective hull!! What are your options to prevent the boat from being taken over by terrorists leaking inside? You can:
--plug the hole and use internal mechanisms in the boat to mop up.
--You can try to drain the ocean so there are no more terrorists to get in.
Which strategy is the U.S. mostly using now to fight terrorists?
As an aside to keep this thread on track, I will say that any nation that is attacked by another nation state has the right to military self-defense against that state without the need for nation building (Afganistan if you will). My intentions here are to show how we might well be wasting enormous resources with our current military action in Iraq while possibly ignoring the police infrastructure needed to really plug the holes in the hull. We cannot ever hope to drain the ocean to really protect us, so John Kerry was basically correct. He just didn't elaborate his idea, which he probably should have.