The efforts of some countries to conceal their plans and activities will succeed despite the best efforts to learn of them. U.S. intelligence deploys, relevant information will be missed. Human agents will not have access to what is needed. Technical systems will not be in the right place at the right time or will focus on the wrong target or will simply be thwarted by bad weather. Even if relevant information is physically acquired by technical systems, it may not be processed in a manner that permits analysts to identify or use it.
Analysis is subject to similar foibles.
It may be based on intelligence that proves inaccurate or unreliable or fails to take into account all of the available information. It may address the wrong issue or reach the wrong conclusions or reach the policymaker too late to influence the decision at hand. One should not expect perfection. Intelligence is simply a hedge against uninformed decisionmaking, and even the most sophisticated of collection systems and analytical talent cannot provide guarantees. Compared with the rest of the world, the intelligence capabilities of the United States are immense.