JAMES CLAPPER: Neither one of those attempts were successful. And-- it's because the constant pressure we're keeping on this groups that they're not able to develop I think the capabilities, the sophistication, the skills and the training to carry out those attacks. I'm not saying that-- you know, we're-- we're not concerned about the ability to penetrate our defenses. Like-- Abdulmutallab in terms of getting on that plane. And that's why-- Secretary Napolitano and Homeland Security have done a lot of work since last Christmas to make it-- much more difficult for an individual like that with something in their underwear to get on board a plane and get to the United States.
JANET NAPOLITANO: It--
JOHN BRENNAN: I think it also illustrates the importance of-- of a-- of a well informed citizenry, too, which also forms-- one of those-- a very important layer of that lay-- multi-layer defense.
JANET NAPOLITANO: But I think it's fair to say that-- let's take-- we're almost at the one year anniversary of-- Abdulmutallab-- otherwise known as the Underwear Bomber. And he had-- PETN explosive material in-- in his under-- undergarments.
DIANE SAWYER: Powerfully--
JANET NAPOLITANO: And-- and he--
DIANE SAWYER: --explosive.
JANET NAPOLITANO: --got-- should-- should you be able to detonate it, absolutely. And he got it onto a plane. That should not have happened. But what we did is-- step back and said, "Well, how did he get that on the plane?" Recognizing at that point that this is really a global issue. And so we addressed it internationally.
DIANE SAWYER: So are you saying, as we know, his father had gone to the embassy to let the embassy-- he was paying cash. He had no bags. He was on the greater list. He was not on the smaller and the-- not on the no fly list. But he was on the greater list. There was no trigger to revoke his visa. Even with everything that had happened, are you saying this could never happen again because of what's been done in this past year?
JANET NAPOLITANO: I'm saying that-- what we have done in this past year-- I would-- say would pick him up. We would prevent him from getting on that plane from Amsterdam to Detroit. That's more international-- protocols put in place. It's-- IKEO (PH) the-- the-- U.N.'s aviation branch-- working with us, internationally and around the world, to adopt 190 nations'-- new international aviation-- requirements. It's the United States-- putting more intel-- that we have-- here-- and shipping it abroad so that-- those who are allowing individuals to board planes abroad have it before a boarding pass is issued. It's more information collection and sharing at the international level. So there are-- a number of steps-- as we go back and look at what happened last Christmas, to say, "How did this individual get on the plane and how do we prevent that from happening again?"
DIANE SAWYER: We remember-- Mr. Brennan, your coming out and saying-- standing up and saying, "I told the President I let him down."
JAMES CLAPPER: Uh-huh (AFFIRM).
DIANE SAWYER: Will you ever have to say that again?