TIME.com: Your book is a welcome change from much of the discussion about terrorism because it actually offers a universal definition — terrorism is any form of warfare that deliberately targets a civilian population. Has the fact that your definition can apply to actions taken by regular armies as well made people uncomfortable?

Caleb Carr: Very little of the discussion about terrorism is based on a clear definition. Most people are hard-pressed to argue with the one I'm offering. The problem it raises for many people is what I consider the virtue of the definition: that it doesn't just apply extremist organizations, but includes the actions of governments as well. States can engage in terrorism just as much as extremist organizations can.

And presumably the fact that you include a number of U.S. actions in the past in your definition of terrorism provokes some prickly response. After all, Osama bin Laden in his first propaganda video after September 11 cites Hiroshima — was Hiroshima an act of terrorism?

Hiroshima is a very difficult call. Truman was told that both Hiroshima and Nagasaki were significant military targets. So he may not have had the intent, but the fact that the military targets in each of those cities were negligible means that dropping the atomic bomb there would fit my definition of terrorism. It was an attempt to break Japan's will to resist by attacking Japanese civilians. And when you look at American military history, that's a very consistent thread — one that we've we managed to break with during the Afghan campaign, finally.

Why do you argue that terrorists are soldiers, rather than simply criminals?

Because if we are to respond correctly, of understanding of terrorism has to be based on reality. And that's been a strength of the current campaign in Afghanistan, which has confronted terrorism as a form of warfare. We confronted al Qaeda and the Taliban on the basis that they're de facto soldiers, whether or not they're fighting for a recognized country or abiding by the various Geneva conventions. That was the basis of our success. The failures of the last 20 years in dealing with terrorism came because we tried to deal with them as criminals, which they're not. We may wish that they were simply criminals, but in their own minds, and in their actions, they're soldiers.

Why doesn't terrorism work? Surely a case can be made that in some instances it has actually forced political changes?

No. Terrorism always makes it more difficult for those who're using it to achieve their political ends. Look at the Palestinians. At the beginning of the intifada, Arafat was sending young people armed with stones against Israeli soldiers, and the Israeli response created a huge swing in public opinion towards the Palestinians to the point where they're now being vilified by the U.S. and there's no longer any criticism of Israel's actions. But when they turned to suicide bombings, opinion swung in the opposite direction. Because Palestinian terrorism is so severe and so extreme, it's taking all the attention away from anything that the Israelis are doing. And you can't help but view that as a self-defeating tactic.

Among the most startling of your recommendations for fighting terrorism is the abolition of the CIA. Why will this help?

I advocate folding the work done by the CIA into the conventional military. And the way the campaign in Afghanistan was run, for the first time many of those jobs usually done by the CIA were finally left up to the people who should be responsible, the military. It's a question of accountability. The CIA has no genuine accountability, neither budgetary or operationally. When the CIA undertakes an operation, they're given a blank check. And that can have disastrous consequences. The military has to account for its actions, first to its immediate superiors and then all the way up to the executive branch. The CIA has no such accountability, and that's been the danger of it since the day it was formed.

President Bush has extended the war on terrorism to cover an "Axis of Evil" comprising Iraq, Iran and North KoreaŠ

The "Axis of Evil" is an immensely unfortunate permutation of what had been a very hopeful situation. I interpret it as President Bush letting the success in Afghanistan run away with him a little. The insult to North Korea does not concern me much, nor does the insult to Saddam. But the inclusion of Iran is a very dangerous and foolish mistake to make. Various elements in Iran had been trying to indicate to us for a long time that they're interested in changing their relationship to us, and their internal situation. They had been very conciliatory to us during the Afghan campaign, and Iran is precisely the kind of government that we need to be sounding out right now, to find out where we can reach compromise ground to figure out what we can do to eliminate terrorism, what we can do to get fundamentalist Muslim states involved in the elimination of terrorism, and what steps we can take to end things that they consider American terrorism. The constant and immediate assumption that America is not engaged in any terrorist activity in the world right now is not going to help us.

What's the most important lesson you'd ask those in power to take from your book?

To build on what was done in Afghanistan in terms of avoiding civilian casualties. That was something that Donald Rumsfeld was determined to do in Afghanistan, and to a very large extent he managed to achieve that. There was no deliberate targeting of civilians, and no deliberate use of weapons aimed at civilians.

Also See:
• TIME.com's Exclusive Excerpt of "The Lessons of Terror"
• Caleb Carr's Novella "Killing Time"