I fired a lot of senior people myself and I think the key, when you feel compelled to remove a senior official, is essentially to have all your ducks in a row at the beginning. Have everybody understand what the rationale was.

I have tried to maintain civil relationships with everyone I meet - and, even if I violently disagree with them, try to be respectful.

What I know concerns me. What I don't know concerns me even more. What people aren't telling me worries me the most.

I think in the policies that have been followed since the president Donald Trump came into office, there really hasn't been any slack cut for the Russians. And I think one of the things that has surprised people has been that the relationship between the United States and Russia has in fact deteriorated since the election.

I think in the context of senior government positions, I think an anecdote of what I told President-Elect Barack Obama when we had our first meeting. And I said, "You don't know me. Can you trust me? Why do you think you can trust me?" and so on. But at the end, I said, "You can count on me to be loyal to you. I will not leak. I will keep my disagreements with you private. And if I cannot be loyal, I'll leave." Loyalty means doing what you think is in the best interest of that person as well as the country.

One of the big changes in the Congress since I first came to Washington is that all of these folks go home every weekend. They used to play golf together; their families got to know each other, go to dinner at each other's homes at weekends - and these would be people who were political adversaries.

Some people have said, in so many words, that I'm kind of wooly-headed in believing that the Iranians would see not having nuclear weapons as more in their security interest than not.