“As leaders, we are never responsible for filling anyone else's cup. Our responsibility is to empty ours.”

2011, Address on interventions in Libya (March 2011)
Context: Much of the debate in Washington has put forward a false choice when it comes to Libya. On the one hand, some question why America should intervene at all — even in limited ways — in this distant land. They argue that there are many places in the world where innocent civilians face brutal violence at the hands of their government, and America should not be expected to police the world, particularly when we have so many pressing needs here at home.
It’s true that America cannot use our military wherever repression occurs. And given the costs and risks of intervention, we must always measure our interests against the need for action. But that cannot be an argument for never acting on behalf of what’s right. In this particular country — Libya — at this particular moment, we were faced with the prospect of violence on a horrific scale. We had a unique ability to stop that violence: an international mandate for action, a broad coalition prepared to join us, the support of Arab countries, and a plea for help from the Libyan people themselves. We also had the ability to stop Qaddafi’s forces in their tracks without putting American troops on the ground.
To brush aside America’s responsibility as a leader and — more profoundly — our responsibilities to our fellow human beings under such circumstances would have been a betrayal of who we are. Some nations may be able to turn a blind eye to atrocities in other countries. The United States of America is different. And as President, I refused to wait for the images of slaughter and mass graves before taking action.

Running from Safety: An Adventure of the Spirit (1994)

Book 2, Chapter 7 “A Mechanical Man” (p. 395)
The Steel Tsar (1981)

The Autobiography of Kwame Nkrumah

Source: Farnham's Freehold (1964), Chapter 4 (p. 75)

Third Session of Parliament (June 30, 2007)

The reference to Cassius is that of the character in William Shakespeare's play Julius Caesar. Listen to an mp3 sound file http://www.otr.com/murrow_mccarthy.shtml of parts of this statement.
See It Now (1954)
Context: No one familiar with the history of this country can deny that congressional committees are useful. It is necessary to investigate before legislating, but the line between investigating and persecuting is a very fine one and the junior Senator from Wisconsin has stepped over it repeatedly. His primary achievement has been in confusing the public mind as between the internal and the external threats of communism. We must not confuse dissent with disloyalty. We must remember always that accusation is not proof and that conviction depends upon evidence and due process of law. We will not walk in fear, one of another. We will not be driven by fear into an age of unreason, if we dig deep in our history and our doctrine, and remember that we are not descended from fearful men — not from men who feared to write, to speak, to associate and to defend causes that were, for the moment, unpopular. This is no time for men who oppose Senator McCarthy's methods to keep silent, or for those who approve. We can deny our heritage and our history, but we cannot escape responsibility for the result. There is no way for a citizen of a republic to abdicate his responsibilities. As a nation we have come into our full inheritance at a tender age. We proclaim ourselves, as indeed we are, the defenders of freedom, wherever it continues to exist in the world, but we cannot defend freedom abroad by deserting it at home. The actions of the junior Senator from Wisconsin have caused alarm and dismay amongst our allies abroad, and given considerable comfort to our enemies. And whose fault is that? Not really his. He didn't create this situation of fear; he merely exploited it — and rather successfully. Cassius was right. "The fault, dear Brutus, is not in our stars, but in ourselves." Good night, and good luck.