Brigham Young quote: “[W]e shall continue to do it until God tell us to stop, or until we pass into sin and iniquity, which will never be.”

“We have used it in order to shorten the agony of war, in order to save the lives of thousands and thousands of young Americans. We shall continue to use it until we completely destroy Japan's power to make war. Only a Japanese surrender will stop us.”

Harry Truman (1884–1972) American politician, 33rd president of the United States (in office from 1945 to 1953)

Report on the Potsdam Conference (1945)
Context: I realize the tragic significance of the atomic bomb. Its production and its use were not lightly undertaken by this Government. But we knew that our enemies were on the search for it. We know now how close they were to finding it. And we knew the disaster which would come to this Nation, and to all peace-loving nations, to all civilization, if they had found it first. That is why we felt compelled to undertake the long and uncertain and costly labor of discovery and production. We won the race of discovery against the Germans.
Having found the bomb we have used it. We have used it against those who attacked us without warning at Pearl Harbor, against those who have starved and beaten and executed American prisoners of war, against those who have abandoned all pretense of obeying international laws of warfare. We have used it in order to shorten the agony of war, in order to save the lives of thousands and thousands of young Americans. We shall continue to use it until we completely destroy Japan's power to make war. Only a Japanese surrender will stop us.

“We may not stop until we have done our part to fashion a world in which there shall be some share of fellowship; which shall be better than a den of thieves.”

Learned Hand (1872–1961) American legal scholar, Court of Appeals judge

"A Pledge of Allegiance" - speech for "I Am an Amercan Day" Central Park, New York, New York. (20 May 1945) Hand credited H. G. Wells with inspiring some of the ideas expressed in this speech.
Extra-judicial writings
Context: We may not stop until we have done our part to fashion a world in which there shall be some share of fellowship; which shall be better than a den of thieves. Let us not disguise the difficulties; and, above all, let us not content ourselves with nobel aspirations, counsels of perfection, and self-righteous advice to others. We shall need the wisdom of the serpent; we shall have to be content with short steps; we shall be obliged to give and take; we shall face the strongest passions of mankind — our own not the least; and in the end we shall have fabricated an imperfect instrument. But we shall not wholly have failed; we shall have gone forward, if we bring to our task a pure and chastened spirit, patience, understanding, sympathy, forbearance, generosity, fortitude, and, above all, an inflexible determination. The history of man has just begun; in the aeons which lie before him lie limitless hope or limitless despair. The choice is his; the present choice is ours. It is worth the trial.

“Fondly do we hope — fervently do we pray — that this mighty scourge of war may speedily pass away. Yet, if God wills that it continue until all the wealth piled by the bondman's two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said, 'The judgments of the Lord are true and righteous altogether.'”

Abraham Lincoln (1809–1865) 16th President of the United States

1860s, Second Inaugural Address (1865)
Context: The Almighty has his own purposes. 'Woe unto the world because of offenses! for it must needs be that offenses come; but woe to that man by whom the offense cometh.' If we shall suppose that American Slavery is one of those offences which, in the providence of God, must needs come, but which, having continued through His appointed time, He now wills to remove, and that He gives to both North and South, this terrible war, as the woe due to those by whom the offence came, shall we discern therein any departure from those divine attributes which the believers in a Living God always ascribe to Him? Fondly do we hope — fervently do we pray — that this mighty scourge of war may speedily pass away. Yet, if God wills that it continue until all the wealth piled by the bondman's two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said, 'The judgments of the Lord are true and righteous altogether.

“What kind of a people do they think we are? Is it possible they do not realise that we shall never cease to persevere against them until they have been taught a lesson which they and the world will never forget?”

Winston S. Churchill book The Second World War

Speech to a joint session of the United States Congress, Washington, D.C. (26 December 1941) http://www.winstonchurchill.org/learn/speeches/speeches-of-winston-churchill/1941-1945-war-leader/288-us-congress-1941.
The Second World War (1939–1945)
Context: When we consider the resources of the United States and the British Empire compared to those of Japan, when we remember those of China, which has so long and valiantly withstood invasion and when also we observe the Russian menace which hangs over Japan, it becomes still more difficult to reconcile Japanese action with prudence or even with sanity. What kind of a people do they think we are? Is it possible they do not realise that we shall never cease to persevere against them until they have been taught a lesson which they and the world will never forget?
Members of the Senate and members of the House of Representatives, I turn for one moment more from the turmoil and convulsions of the present to the broader basis of the future. Here we are together facing a group of mighty foes who seek our ruin; here we are together defending all that to free men is dear. Twice in a single generation the catastrophe of world war has fallen upon us; twice in our lifetime has the long arm of fate reached across the ocean to bring the United States into the forefront of the battle. If we had kept together after the last War, if we had taken common measures for our safety, this renewal of the curse need never have fallen upon us.
Do we not owe it to ourselves, to our children, to mankind tormented, to make sure that these catastrophes shall not engulf us for the third time?

“It's not going to stop until "we" stop it. And it's not just white man that's doing this to Brenda. It's not just white man that's keeping us trapped. It's "black."”

Tupac Shakur (1971–1996) rapper and actor

And we have to find the new African in everybody... But before we can be African, we gotta be black first.
1990s, Malcolm X Grassroots Movement, Atlanta (1992)