From The New Yorker:
AMY DAVIDSON: Sy, in your first article after 9/11—just a few weeks after—you quoted a senior C.I.A. official who, you wrote, “confirmed that the intelligence community had not yet developed a significant amount of solid information about the terrorists’ organization, financing, and planning.” He said, “One day, we’ll know, but at the moment we don’t know.” Has that day arrived?
SEYMOUR M. HERSH: No, not in my view. He also said at the time that there was a debate about whether the attacks were a long-planned, deep-cell operation, and we were going to be looking at cell operations like this throughout the country—major embedded groups of Al Qaeda, what you will. The other possibility was that the nineteen hijackers were the equivalent of a pickup basketball team that made it to the Final Four. His guess was the latter. I think that’s true. I think the nineteen guys, however skilled, were more lucky than anything else, because of our lack of preparation. But we really know very little about how that operation worked, even now.
More here.