Unless we free ourselves from a dependence on these fossil fuels... we are condemning future generations to global catastrophe

There have been times where, let's say on LGBT issues, when we were trying to end Don't Ask, Don't Tell, and I got the Pentagon and Bob Gates, a Republican holdover from the [George W.] Bush administration, to authorize a study of how you might end Don't Ask, Don't Tell, headed up by Jeh Johnson, who at that time was a council to the Justice Department. And it was going to take a year to conduct that study, issue a report, and figure out how it might be implemented, what effect it would have on unit cohesion and military effectiveness.

My strong preference has always been to legislate when I can get legislation done.

I know what the counterterrorism feels like because I was there. But I also operated within limits. And within the United States government, we've decided long ago that there are limits on what we're going to do in the war against terrorism.

The most powerful political moments for me come when I feel like my actions are aligned with a certain truth. I can feel it. When I'm talking to a group and I'm saying something truthful, I can feel a power that comes out of those statements that is different than when I'm just being glib or clever.

What we've said to the girls is: 'If you guys ever decide that you're going to get a tattoo, then mommy and me will get the exact same tattoo, in the same place.' And we'll go on YouTube and show it off as a family tattoo.

Of course, violence will not end with our combat mission. Extremists will continue to set off bombs, attack Iraqi civilians and try to spark sectarian strife. But ultimately, these terrorists will fail to achieve their goals.