"[T]he Obama administration may be attempting to appease its antiwar base ... or trying to look good for the chattering classes."

John Yoo defends his memos:

Imposing Fourth Amendment standards on military action would have made the Civil War unwinnable -- combat occurred wholly on U.S. territory and enemy soldiers were American citizens. The military does not have the time to obtain warrants before soldiers fire upon enemy targets and personnel; the battlefield does not provide the luxury to collect evidence needed to meet probable cause standards in civilian courts. Even if the Fourth Amendment applied, we believed that courts would judge military action under a standard of "reasonableness" -- as they might review a police officer who fires in self-defense -- rather than demand a warrant to use military force to stop a terror attack....

But if the administration chooses to seriously pursue those officials who were charged with preparing for the unthinkable, today's intelligence and military officials will no doubt hesitate to fully prepare for those contingencies in the future. President Obama has said he wants to "look forward" rather than "backwards." If so, he should not restore risk aversion as the guiding principle of our counterterrorism strategy.