Amid some political turmoil--renewed attacks from Republicans, some big questions from the concerned public about watch-lists, and the closing of the U.S. embassy in Yemen--following the Christmas Day incident over Detroit, the White House dispatched its top counterterrorism official, Deputy National Security Advisor John Brennan, to the Sunday talk shows this week to face up to questions about American security and generally tell people what's going on. Brennan is leading the review of national security/intelligence failures that led up to Umar Farouk Abdulmutallab's near-bombing.

Homeland Security Secretary Janet Napolitano had, effectively, become the face of the administration's response in the days after the Christmas attack, before the president himself engaged reporters in Hawaii: she went on CNN's "State of the Union" two days after the incident, and her "system worked" sound byte got replayed over and over; Brennan provided a new face today, one more narrowly focused on intelligence and counterterrorism--that's Brennan's background; he doesn't have the broad, survey responsibilities of the DHS secretary--as well as some sound bytes of his own.

Politically, the big one came on NBC's "Meet the Press," where he scolded former Vice President Dick Cheney for leveling attacks on President Obama, saying he's "very disappointed" in the former VP, who must either be "willfully mischaracterizing" Obama's positions or "ignorant of the facts." (In a statement to Politico, Cheney said recently that Obama is "trying to pretend' the nation isn't at war.) Strong stuff from Brennan (video here):

I'm very disappointed in the vice president's comments.  I'm neither Republican nor Democrat.  I've worked for the past five administrations.  And either the vice president is willfully mischaracterizing this president's position, both in terms of the language he uses and the actions he taken--he's taken, or he's ignorant of the facts.  And in either case, it doesn't speak well of what the vice president's doing.  The clear evidence is that this president has been very, very strong.  In his inaugural address, he said, "We're at war with this international network of terrorists." We continue to say that we're at war with al-Qaeda.  We're trying to give it some clarity.  And we have taken the fight to them.  We've continued, in fact, many of the, of the activities of the previous administration.  I would not have come back into this government if I felt that this president was not committed to prosecuting this war against al-Qaeda.  And every day I see it in the president's face, I see it in the actions he's taken, and so I'm confident that this country is, in fact, protected by this president's position on al-Qaeda and against terrorist activities.  We're going to continue to do this, we're going to do it hard, we're going to do it constantly.

There's been a lot of talk about how the same questions are getting raised about the intelligence community now as were voiced, almost identically, immediately after 9/11--"connecting dots," sharing information between branches of the U.S. security network, etc.--and here's how Brennan answered those criticisms on ABC's "This Week," with Terry Moran taking the place of George Stephanopoulos: "Well, in fact, prior to 9/11, I think there was reluctance on the part of a lot of agencies and departments for sharing information. There is no evidence whatsoever that any agency or department was reluctant to share," Brennan said. And in almost the same words on CNN's "State of the Union": "Well, first of all, it's not like 9/11. There was no indication that any of these agencies or departments were intentionally holding back information," Brennan told fill-in host Gloria Borger.

Brennan said in multiple interviews that the U.S. embassy in Yemen was closed because of intelligence indicating that an al Qaeda attack on the embassy was coming. Asked what the U.S. is doing in Yemen to clam down on al Qaeda, Brennan told NBC's David Gregory that the U.S. is providing ""security, intelligence, and military support to the Yemeni government."

On whether or not Americans should be more concerned about al Qaeda attacks than they were three weeks ago, Brennan tells CNN that "I think we'll see continued attempts. Al Qaida is determined to carry out attacks and be successful. We keep thwarting their attacks, but they keep pressing." It's also "unknown" whether body scanners would have detected the explosives Abdulmutallab carried onto the plane, Brennan told NBC.

Brennan also pointed out that the Obama administration hasn't sent as many Guantanamo detainees abroad as the Bush administration did, stressing that the ongoing Guantanamo closure process will be done carefully.

And he defended Napolitano, taking on some of that "system worked" criticism, drawing the distinction that she was talking about the "system" after the incident occurred, not more. Here's how Brennan responded when Gregory asked him if people need to get fired after this incident:As the president said, there's going to be accountability at all levels, and he has to take a look at it. But let me say a couple of things on this.  First of all, Janet Napolitano has done a tremendous job over the past year.  I've worked very closely with her, and I know there were a number of criticisms about her comments about "the system worked." What she was referring to, and she's clarified her remarks, the system worked after the incident.  What the president wants to do is to make sure that we're able to take the corrective steps necessary to prevent this from happening again.  But he needs to hold everybody accountable, including me.