It is possible for leaders or regimes to be cruel, bigoted, twisted in their world views and still make rational calculations with respect to their limits and their self-preservation.

[The White House staff] start bringing in their kids, who you think should be babies and now are in second grade or something, and you've watched them grow up. So I think what ends up happening is you end up maintaining those networks and those contacts, but the concentrated interactions and experience that you have here, I don't think, I don't expect you can duplicate anyplace else.

Iran is a state sponsor of terrorism. And for them to be able to provide nuclear technology to non-state actors, that's unacceptable.

We have come from a time of the large-scale, planned, Al Qaeda-style attacks, to the encouragement of lone wolves: Fort Hood, Chattanooga. To the encouragement of people to act on their own.

The most frustrated and most stymied it is the fact that the United States of America is the one advanced nation on earth in which we do not have sufficient common-sense, gun-safety laws. Even in the face of repeated mass killings.

Iran will for sure have pledged to the international community that it will not develop a nuclear weapon, and now will be subject to an additional protocol, a more vigorous inspection and monitoring regime that lasts in perpetuity.

Today we're seeing that climate change is about more than a few unseasonably mild winters or hot summers. It's about the chain of natural catastrophes and devastating weather patterns that global warming is beginning to set off around the world.. the frequency and intensity of which are breaking records thousands of years old.