I'm not going to be scrambling jets to get a 29-year-old hacker. That was president Obama during Edward Snowden's global odyssey after he revealed the surveillance secrets. A year later, Snowden still sparks a raging debate. Here's ABC's Pierre Thomas. Reporter: Edward Snowden is a traitor and could be a spy, recruited by Russia to target the U.S. That's the suspicion of the man running the NSA when this happened last year. Why would you take hundreds of thousands or million plus documents. Reporter: And Snowden acknowledged the extraordinary scale of what he could have taken. I had access to the full rosters of everyone working at the NSA. The entire intelligence community. And undercover assets all around the world. Reporter: Is he a spy? I don't know the answer to that. I'm concerned that where he is now, he's at least influenced by Russia. The real question is, how far back did that go? We have learned that the Obama administration quietly accessed the phone records of millions of Americans. Reporter: Roughly a year ago, Snowden stole some of the nation's most sensitive secrets and gave them to the media. The first stunning revelation? Verizon was providing the national security agency with phone Numbers of millions of customers. Now, nations have our surveillance playbook and terrorists have changed how they operate. We're losing capabilities to track terrorists. This is a huge impact. Reporter: But Snowden defended his actions. I don't want to live in a world where everything I say, everything I do, everyone I talk to, every expression of creativity or love or friendship is recorded. Reporter: For his supporters, the revelations changed the world as we know it. They say for the better. We have the courts engaging the legality and the wisdom of these programs. The debate would not have happened if not for the actions of Edward Snowden. Reporter: We pressed on why congress, who was supposed to be overseeing his agency, did not know everything that the NSA was doing. Was this case of the NSA withholding information or congress not doing their job? It can't be both. We deal to the Intel communities. We put all the documents on the table and say, here's what we're going to do with this. I can tell you this. We provided those materials. Now, truth in lending, some of this is technical. Reporter: The debate is over the details. Was the NSA revealing too few or Snowden too many? For \"This week\" Pierre Thomas, ABC news, Washington. Thank you, Pierre. Let's bring in ABC news contributor Richard Clarke, form white house terror adviser and author of the new book, \"Sting of the drone.\" Thanks for being with us, dick. I want to ask you, you heard what general Alexander said. To you think that Edward Snowden damaged national security? I know he did. President Obama pointed me to the five-person review group to look into what happened. We had complete access to NSA. I know that he hurt our counterterrorism effort and various other efforts. Give us an example of how he did that or the effect. He may or may not have intended. We don't know. He revealed ways that NSA collects information. And, the terrorists, and others, criminals and others around the world, have stopped using those methods of communications since he revealed them. So we no longer have the heads-up that an attack is coming on our embassy in fill in the blank because of what he did. Sure, he revealed a program, the telephony program, the 215 program, that was a stupid program. That we might not have known about otherwise. So I'm glad we know bit. If there's a silver lining, that's it. It's very small. We're killing the program. It was unnecessary and overly intrusive. It didn't have enough oversight by the courts. So the president is killing the program. That's what we recommended. I want to turn to your book. Which sounds pretty phenomenal. It's called \"The sting of the drone.\" One reviewer had high praise writing that what Tom Clancy did for submarines, Richard a. Clarke does for the drones. What's the picture you're trying to paint here with the drones? I'm sure you didn't reveal any secrets. I couldn't. They reviewed it and took out the secrets. They left a lot in that is very informative. The goal was to write a thriller that you would enjoy laying on the beach. And at the same time, bring people behind the curtain to see how the drone program works now and how potentially it will work this the future. You go to where the drones are flying. You go overseas. You do all of that. I ask the question what happens if the people we're attacking with the drones start attacking us with drones? Because it's easy to have drones in the United States. In fact, they're beginning to be everywhere. Pretty soon, everybody will have one. They're flying for all sorts of purposes. Sheriffs have them. Farmers are them. Some are running into planes. Obviouslily close. It sounds like a great book. Dick Clarke, I'll look forward to some day being on the beach with it. Next, one of the world's <\/p>\n
This transcript has been automatically generated and may not be 100% accurate. <\/p>\n
<\/p>\n