If you don't understand what al Qaeda was trying to do on 9/11, if you don't have a sense of who Osama bin Laden is as a person, if you don't have a sense of what al Qaeda, the organization, was on 9/11, 9/11 appears to be more or less inexplicable.

Bin Laden's death is just a punctuation point on a set of problems they've had for a long time. I think the prognosis for al-Qaida and groups like it is really bad, and that's a good thing.

In February I secured permission to enter Osama bin Laden's compound in the northern Pakistani city of Abbottabad, where he was killed and where he had lived for the last half-decade of his life; the first, and only, journalist to do so.

Bin Laden was 200 miles away from the area where all of these drone strikes were taking out his key leaders in al-Qaida. He was able to indulge in his hobbies... He was making occasional video tapes and audio tapes for release to the wider world.

Often it is important to listen to what people aren't saying.

The image we have of bin Laden in his final years in Abbottabad is of an aging man with a graying beard watching old footage of himself; just another suburban dad flipping though the channels with his remote.

I've interviewed multiple people who know bin Laden... who tend to have a universal picture of what he's like, which is: modest, retiring, unassuming, kind of thoughtful - lots of things that don't fit with a mass murderer, which he is as well.