After the Berlin Wall came down I visited that city and I will never forget it. The abandoned checkpoints. The sense of excitement about the future. The knowledge that a great continent was coming together. Healing those wounds of our history is the central story of the European Union.

You don't have to be a brilliant historian to know that in Europe, messing with countries' borders, messing with their self-determination, their ability to choose their own futures, this is extremely dangerous, and that's why I think it is important to stand up to Putin.

I think the country requires fresh leadership. I do not think I can be the captain to take the country to its next destination.

Yes, America must do the right thing, but to provide moral leadership, America must do it in the right way, too.

You need to set near-term milestones. Put the assumptions down on paper, and make it to your vision or ultimate product. Your team has to understand where they're going. Your partners need to understand where they're going.

We have now under President Obama's leadership had 29 months in a row of private sector job growth. That stretch of positive private sector job growth hasn't happened since 2005. We still have a long way to go, but we are moving in the right direction.

A leader has to 'appear' consistent. That doesn't mean he has to be consistent.

Engaging in a sycophantic way with any politician in the short term is tempting. It offers the lure of access and the promise of influence. But ultimately, it can lead to misreading the environment, giving too much of an ear to the politician's circle, and confining your audience to partisans.