Detailed response and analysis of the inspectors general report on the Boston Marathon bombings:

Two opposite mistakes in an after-the-fact review of a terrorist incident are equally damaging. One is to fail to recognize the powerful difference between foresight and hindsight in evaluating how an investigative or intelligence agency should have behaved. After the fact, we know on whom we should have focused attention as a suspect, and we know what we should have protected as a target. With foresight alone, we know neither of these critically important clues to what happened and why. With hindsight, we can focus all of our attention narrowly; with foresight, we have to spread it broadly, as broadly as the imagination of our attackers may roam.

The second mistake is equally important. It is to confuse the fact that people in official positions, like others, will inevitably make mistakes in carrying out any complicated task, with the idea that no mistakes were really made. We can see mistakes with hindsight that can be avoided in the future by recognizing them clearly and designing solutions. After mistakes are made, nothing is more foolish than to hide them or pretend that they were not mistakes.