Each success only buys an admission ticket to a more difficult problem.

Art is man's expression of his joy in labor.

The nice thing about being a celebrity is that, if you bore people, they think it's their fault.

Donald Trump is a phenomenon that foreign countries haven't seen. So it is a shocking experience to them that he came in to office.

The attitude of the West and of Russia towards a crisis like Ukraine is diametrically different. The West is trying to establish the legality of any established border. For Russia, Ukraine is part of the Russian patrimony.

We cannot always assure the future of our friends; we have a better chance of assuring our future if we remember who our friends are.

The Vietnam War was a great tragedy for our country. And it is now far enough away so that one can study without using the slogans to see what's really happened.

My view of my role is that together with like-minded men and women, I could help contribute to a bipartisan view of American engagement in the world for another period; I could do my part to overcome this really, in a way, awful period in which we are turning history into personal recriminations, depriving our political system of a serious debate.

It was a Greek tragedy. Nixon was fulfilling his own nature. Once it started it could not end otherwise.

Everybody has a hacking capability. And probably every intelligence service is hacking in the territory of other countries. But who exactly does what? That would be a very sensitive piece of information. But it's very difficult to communicate about it. Because nobody wants to admit the scope of what they're doing.

The task of the leader is to get his people from where they are to where they have not been.

A leader does not deserve the name unless he is willing occasionally to stand alone.

It is, after all, the responsibility of the expert to operate the familiar and that of the leader to transcend it.

Leadership is absolutely vital if there are comparable countries which can affect the security of the world you live in. Between Lincoln and Roosevelt's time, America was protected by huge oceans and, in practice, by the British navy. Today, it's different, and the obsession of the Obama administration has been for retrenchment.

I don't see the wisdom in modern politicians that I once saw in men like Dean Acheson, David Bruce, or George Marshall. In my day, the northeastern establishment dominated foreign policy formulation, but the composition and distribution of our population is very different today.

You can't make war in the Middle East without Egypt and you can't make peace without Syria.

University politics are vicious precisely because the stakes are so small.

Ninety percent of the politicians give the other ten percent a bad reputation.

Power is the great aphrodisiac.

I have been a professor, and I have been a policymaker, and as a professor, you think in terms of truth or absolutes.

There cannot be a crisis next week. My schedule is already full.

No foreign policy - no matter how ingenious - has any chance of success if it is born in the minds of a few and carried in the hearts of none.

Moderation is a virtue only in those who are thought to have an alternative.