In these cases, the terrorists were the government and the media
Bruce Schneier summarizes the absurd so-called terrorist plots, such as JFK, Fort Dix, and the Miami Seven, in which the alleged perps were so far from committing the crimes of which they are accused that they had no chance of causing any terror whatsoever. But they didn't need to--the government and the media were more than willing to make mountains out of molehills, or less.
There is a real threat of terrorism. And while I'm all in favor of the terrorists' continuing incompetence, I know that some will prove more capable. We need real security that doesn't require us to guess the tactic or the target: intelligence and investigation -- the very things that caught all these terrorist wannabes -- and emergency response. But the "war on terror" rhetoric is more politics than rationality. We shouldn't let the politics of fear make us less safe.