Have you spoken with any of your sources in government, or now out of government, and if so, what are they saying?

Well, they're saying a variety of things. They're saying this sort of event would actually fit with the general thinking as to what al-Qaida has planned for a so-called second wave to 9/11: numerous airplanes blowing up over the airspace of the United States would, in the mind of the terrorism experts I'm talking to, comport with our view as to al-Qaida's playbook in terms of a second-wave attack to follow 9/11. It would be very visible, there would be lots of casualties, and planes blowing up over large urban areas would of course create havoc.

I thought one of the really fascinating points in your book was that al-Qaida may not have been thwarted from attacking us after 9/11, but they may have made a strategic decision to focus their efforts elsewhere. Are you hearing, or do you think, that this is a strategic shift back to the American mainland?

Well, the thinking is that al-Qaida has the ability to attack us at any time or place of their choosing, that we should not view the passage of time as a kind of proxy for victory and view it in any kind of self-satisfied way, that we're doing something that's stopping them from this next destructive moment. What we know about al-Qaida is that they think very long-term. We think in news cycles; they think in decades.

They have spent a good deal of energy thinking about what is appropriate to follow 9/11. It could take years for them to come up with something that is a sufficiently destructive next act in this drama that they are driving. If the next attack is bigger than 9/11, what it does is create an upward arc of terror and anticipation between that second act and whatever follows, however many years later. I think the other thing that's important here, that the book shows, is really, more than anything else, discretion. They're making decisions. They may not have actually been trying to attack the United States in these ensuing years. Even though folks in government have sort of been taking some credit for the fact that there hasn't been an attack, I think they know better.

The president, in his remarks today, said that the country is safer than it was prior to 9/11. Do you think that's true?

I am not ready to make that claim. And I think the president probably knows that he shouldn't make that claim with any real enthusiasm.

Why is that?

The disclosures in the book, after years of research, and the understanding that is shared by most of the folks right at the very cutting edge of the counterterrorism community, is that the United States mainland is in significant measure indefensible. Al-Qaida will attack at a time and a place of its choosing. They retain capability, they have spores and wannabes and imitators that are very hard to detect because they don't have to be hooked in to any kind of structure or hierarchy, and there is a wide array of people abroad, and I think probably frankly here in the United States, who are auditioning for eternity in the jihadist community.

Is there any danger to that line of thinking, to thinking we've become safer?

To feel safer, to say we are safer than we were -- though it may be politically advantageous -- nudges people, I think, to a kind of complacency, a kind of self-satisfied surety, a feeling that they haven't attacked us in the five years since 9/11 so something must be working. The fact of the matter is, it may mean absolutely nothing that they haven't attacked us in the past five years. As I point out in the book, they may not have been trying to attack us. They are probably waiting for a time and place significant and dramatic beyond 9/11. If we start feeling this sort of self-aggrandizing regard for our abilities and capabilities, we will fall prey to exactly what they are hoping we will: We will be less rigorous.

One of the things that I think is clear about the moment we're in now is that in a way this is a new kind of war, a new kind of conflict we're fighting now, with a kind of global insurgency. We know insurgencies, we've seen many of them through history, and very often it's the case where gleaming armies come down from on high with banners waving and march in to some homeland or other to fight insurgents. It almost never works. Whatever moral claim that the army has made as the trumpets blare soon sinks into the ugliness of destruction, especially amongst civilian populations. In Iraq, in the Israel-Lebanon situation, and in other parts of the globe -- in Afghanistan, to a certain degree -- we are seeing precisely this model. If in not thinking with, let's just say, next-era clarity about the nature of these enemies and what best to do about them -- where we are not involved solely in tactics, which is mostly what has been driving us, tactics where we're often running around like a chicken with no head, and instead thinking about strategy, where actions fall into a larger good, a larger model that essentially bespeaks progress -- we are going to create more and more people around the world who are angry at the United States. The fact is, by virtue of our power, our authority, that's always going to be the case. But if that group, that angry mass of people, grows and grows, and some percentage of them, in this era, are apt to turn to violence, we could be facing a very difficult situation.

[snip]

If our tactics are creating a metastasizing, a growth of that number, then our tactics are not working, plain and simple.

You say in your book that to understand the actions of the U.S. government after 9/11, "it is important to understand ... how desperate they were ... [they] were essentially blind and waiting, with dread, for a 'second wave.'" What we're hearing today is that in the wake of this plot, British Home Secretary John Reid is saying that "we may have to modify some of our freedoms in the short term." Do you see parallels there?

I've said many times, and I say in the book, that the central challenge of this war on terror is to win it with both tactics and some coherent strategy while not compromising those things that make us distinctive as a democracy and distinctive in terms of the long human pageant.

[snip]

Whichever party's in power, whoever's in the White House, power has a way of aggregating itself, and that's why we need checks here that are agreed-upon, that occur during the intervening period between attacks. After the next attack -- and I think it's a matter of when, rather than if -- then the conversation again becomes one dominated by fear. Conversations dominated by fear almost always have outcomes that we later regret.