Comparing Pearl Harbor and "9/11": Intelligence Failure? American Unpreparedness? Military Responsibility?

Claims by some commentators that "9/11" was an intelligence failure like Pearl Harbor, that the United States was unprepared for "9/11" like she was for the Japanese attack on Hawaii, and that, like Pearl Harbor, the military was not ready to defend against al Qaeda's terrorist attacks on the World Trade Center and Pentagon are incorrect. On the contrary, an analysis of the two events reveals that they are more dissimilar than alike.