I am fully supportive of 'open service' and committed to LGBT military families.

I think this is the biggest lesson a president or any of us who has responsibility to govern have to learn: There are always consequences to actions that you take. There are consequences to inaction.

The United Nations has a critical role to play in promoting stability, security, democracy, human rights, and economic development. The UN is as relevant today as at any time in its history, but it needs reform.

Imposing democracy through force is a roll of the dice.

I'm the first secretary of defense that's had to deal with sequestration. I've prepared two budgets that deal with sequestration. And you bring the chiefs together, the leadership of this enterprise together, to work through, how do we then take these cuts? Where do we apply those cuts? Readiness is the first thing that suffers.

It is easy to get into war, not so easy to get out.

There are always consequences to actions that you take. There are consequences to inaction. And thinking through, asking the questions, "Well, then what happens? What comes next?" is critically important.