Finally) ...over the course of my career I have seen a number of challenges to our democracy. The Russian government's efforts to interfere in our el… - Robert Mueller

I think we're certainly vulnerable when it comes to the type of information that is out there. The type of information that is out there and available to those that want to find it and want to damage and harm to us. We're also to a certain extent vulnerable by the fact that we live by the rules passed by Congress. If I want to get an application before the court to intercept somebody's conversations, I have to show probable cause to believe that person is affiliated with a terrorist group. And if I don't get the probable cause, I can't do it. And we've had instances, Awlaki, a relatively famous individual exporter of the type of terrorism we've seen in the United States, was doing videos for a substantial period of time before the Fort Hood shooting, and it was only after that that we found out he was involved in the operations. Any other country, they may well have been up on his wire beforehand, because there's no responsibility of showing a court that there's probable cause to believe that this individual is involved in terrorist activities.

After September 11th, you had core al Qaeda in Pakistan and Afghanistan with (Osama) bin Laden. Bin Laden was killed. You have al Qaeda growing in countries like Somalia, but most particularly in Yemen. And there's still substantial threat out of Yemen. And now you have the countries in the Arab Spring: Tunisia, Libya, Syria, Mali; Egypt most recently, where they're breeding grounds for radical extremists who may not stay there, but may present an attack. And, finally, you have, within the United States, the growth of homegrown, radicalized extremists who are radicalized on the Internet and then get their instructions for developing explosives on the Internet, as well.

I think there's a good chance we would have prevented at least a part of 9/11. In other words, there were four planes. There were almost 20 — 19 persons involved. I think we would have had a much better chance of identifying those individuals who were contemplating that attack.