The United States must learn to defend against uncertainty. There is no way to predict the probable nature of the threat that can be firmly rooted in either an analysis of past patterns of attack, or a clearly identifiable threat from specific countries or foreign and domestic extremists. Furthermore, U.S. planning and analysis often tends to react to an emotive and generic approach to terrorism, and/or generalize from patterns and incidents that simply do not justify such generalizations. There has been only limited, sporadic efforts to develop national net assessments of the threat posed by foreign terrorism and no matching effort to create comprehensive net assessment of domestic threats. The net assessments that have addressed foreign terrorism have generally failed to address higher levels of asymmetric warfare and to provide any net technical assessment of how methods of attack may evolve in the future and what technology can do to improve defense.
Many elements of the U.S. government seem to find it difficult to accept the fact that asymmetric warfare is only illegal or illegitimate in the eyes of those who do not need to use such tactics, or find them to be the most effective form of attack, and the fact that the future threat posed by covert or proxy attacks by state actors may be at least as important, and far more lethal, than the threat posed by foreign and domestic terrorist-extremist groups and individuals.