Coming from the world of science, I tend to look at questions empirically, asking what data exists that sheds light on the problem and whether we can find causal relationships. But when it comes to political questions, while they may still be empirical questions, very often we have at most correlations and as a result there may be only political answers.
Take for instance the question of whether the massive expenditures on the war on terror, coupled with the invasions of privacy and illegal governmental activity that have been revealed, have had any success in reducing the terrorist threat. To answer that question, we at least need some basic metrics that tell us whether the actual number of terrorist attacks and threats have decreased or decreased. This is a question that is fraught with uncertainty since the very definition of those things is in dispute.
But suppose for the sake of the argument we assume that the number of terrorist attacks has decreased. What policy implication does that have? Supporters of the national security state (like the congressional heads of the intelligence committees senator Diane Feinstein and congressman Mike Rogers) will argue that this indicates that these programs are working and so they need to be expanded to reduce the threat even more. But suppose the numbers indicate that the terrorist threat has increased, then they will argue that this shows the need for even greater government action. In the absence of evidence for causality, the conclusion determines the argument, not the other way around.
The government may have access to information that shows causal connections between their actions and results but since the government is both secretive and dishonest, we cannot trust their claims since they almost always use data selectively to support whatever plan of action they have decided on for other reasons.
Stephen M. Walt argues that this is what makes the debate over the war of terror so embarrassing.
Still, it really is important to get this right: Just how serious is the threat, some 12 years after the 9/11 attacks? In terms of the direct harm to Americans in the United States, the danger appears to be quite modest. So why are Feinstein and Rogers so animated by this latest set of developments?
My larger concern is that we have also created a vast counterterrorism industry that has a vested interest in continuing this campaign. Those in the industry are the most prominent and visible experts, but fighting terrorists is also a meal ticket for many of them and self-interest might naturally incline them to hype the threat.
War is a very lucrative business in the US. Is it any surprise that the US is constantly on the prowl for wars to wage, either against countries or ideologies?