There is not an inherent contradiction between a Ukraine that has longstanding historic and cultural ties to Russia, and a modern Ukraine that wants to integrate more closely with Europe.

There are no cookie-cutter solutions that you can apply from one circumstance to another. They're different. Our interests, as implicated, are different. The tools we have at our disposal are different.

I think it's very, very important that in foreign policy and national security decision making, as in any other realm, that there be a range of diversity that reflects the full complexity of America. We should draw on those experiences to inform our decision making.

I have been to Libya and walked the streets of Benghazi myself.

President Obama is perhaps the smartest person I've ever worked with.

If you're trying to get something done, there will always be people who don't want to see you get something done, or who have a stake in the status quo. And if they approach that through ad hominem criticism of you, you've got to have enough confidence and thickness of skin to be able to endure.

Peace, prosperity, and democracy cannot endure if imposed from the outside. We should cease to make false distinctions between peacekeeping and prevention; they are in fact inextricably linked.