Author Mark Mazzetti talks about how the CIA has moved away from its original mission of spying in his new book "The Way of the Knife: The CIA, a Secret Army, and a War at the Ends of the Earth."

The CIA was first formed in 1947 and its main responsibility was to keep tabs and be up-to-date with their knowledge of all events taking place around the world, and gather information about foreign governments. In one word, their main duty could be described as "spying". However, according to author Mark Mazzetti, the agency has long moved away from its original mission. Mazzetti documents the same in his book "The Way of the Knife: The CIA, a Secret Army, and a War at the Ends of the Earth."

On the book's opening scene, where CIA officers present a plan to Vice President Dick Cheney

"It is a plan to hunt down and kill people around the world. And the idea was, if the CIA found people where the military couldn't go or they couldn't send drones - you know, this could be in European cities, this could be in populated areas - that the CIA would cobble together hit teams to go kill those people. Now, some of this has been reported before, but for the book, I describe a scene which hasn't been reported, where Cheney is sort of giving this authorization, and it's the scene where it's the beginning of the new CIA, where the CIA is identifying targets to hunt and kill."

On internal disagreements over whether the CIA should return to killing targets

"One of the things that I try to draw out in the book is how much, prior to 9/11, there really was tension in the CIA about whether they should get back into the killing business. A whole generation of officers who had come in after the Church committee, so some who came in the late '70s, sort of were trained in traditional spycraft, were trained and taught that the CIA doesn't kill people, the military kills people. By 9/11, a lot of those officers had reached senior levels at the CIA. So in the fights over whether they should kill Osama bin Laden, before 9/11, with a Predator [drone], there's sort of a morality play at the CIA about whether ... the CIA, a spy agency, should be doing this. So what you see after 9/11, you know, famously the cliche is the gloves came off. And it's true."

On whether, with vice presidential authorization, the CIA could legally use hit squads

" Our authorizations are incredibly broad to go do this around the globe, and if you can identify someone as associated with al-Qaida, even tangentially, then you are authorized to capture and kill them.

"Well, the authorizations were quite broad after 9/11 - that the CIA got, that Congress authorized the military to use, was to go find, capture or kill al-Qaida. Now, I should point out that the hit squads had various incarnations over the years. It was, originally it was a CIA operation, then it was eventually outsourced to Blackwater, the contractor. There's no evidence that this specific program was ever used, or that these squads ever actually carried out an operation.

"But there was this feeling after 9/11 that, sure, it's legal, the authorizations were there. Our authorizations are incredibly broad to go do this around the globe, and if you can identify someone as associated with al-Qaida, even tangentially, then you are authorized to capture or kill them. I think it's something that we're wrestling with now, or the government is wrestling with now, is these authorizations that were put in place in these frantic days after 9/11 are still in place."

On the CIA's use of drone strikes

"The CIA has become a machine for killing in many ways. The counterterrorism center has become, in many ways, the sort of beating heart of the agency that does manhunting. And the drone operations are something that two successive White Houses have embraced. You could argue that the current administration, the Obama administration, has embraced it even more than its predecessor. And these questions of 'Should the CIA stay in the killing business? Should they be focused on drone strikes? Or should that be something that the military should do?' It is something that is unresolved but is certainly being discussed."

On whether the focus on counterterrorism has hurt the CIA's ability to spy

"One of the things I write about in the book was how behind the curve the CIA was on the Arab Spring. And this caused a lot of frustration at the White House, where the CIA was incapable of sort of getting a grasp on these revolts. And this is a big concern, not only in the CIA but in the White House, other parts of the American government, that the traditional missions of the CIA are being atrophied, or are atrophying, because of this intense focus on manhunting."

On where the CIA is going next

"Well, one of the interesting things that is playing out now is that John Brennan, who was President Obama's top counterterrorism adviser, now is the CIA director, has made it clear to some degree in his congressional hearing that he does have concerns about the direction of the CIA - that it should not be focusing on traditional military activities. That being said, John Brennan has also been at the center, over the last four years, of this escalation of drone strikes. But now that he's out at Langley - and he is a CIA veteran - it will be interesting to see if he does try to rein it in. There's some evidence that he's trying to do that, but I think this is something that could take years.

"And even if you were to, tomorrow, say, 'OK, the CIA is out of the killing business,' we have a whole generation now of CIA officers who came in since 9/11 who have learned manhunting and killing, and it's not so easy to retrain people in traditional spy missions. So this is really something that will take a long time even if CIA