“I see that we must strike a balance. We have nearly reached the limit of our powers of resistance. The war must be ended.”
Remarks made at the meeting of the German warlords at Advanced General Headquarters at Avesnes (11 August 1918), quoted in John Terraine, To Win A War: 1918 The Year of Victory (London: Cassell, 2003), p. 121
1910s
Help us to complete the source, original and additional information
Wilhelm II, German Emperor 64
German Emperor and King of Prussia 1859–1941Related quotes
Source: The Inefficient Stock Market - What Pays Off And Why (1999), Chapter 15, The Wrong 20-yard Line, p. 148

Source: Earthsea Books, The Farthest Shore (1972), Chapter 4, "Magelight" (Ged)

Values Voter Summit 2011-10-08, quoted in * Beck: "There Is A Race War That Is Going On In Our Country"
Media Matters for America
2011-10-08
http://mediamatters.org/mmtv/201110080003
2011-08-17
2010s, 2011

This may be derived from lines in the movie Gandhi (1982); such statements have not been located among published sources.
Disputed

“We must help to the limits of our strength. And we will.”
Report on the Potsdam Conference (1945)
Context: Any man who sees Europe now must realize that victory in a great war is not something you win once and for all, like victory in a ball game. Victory in a great war is something that must be won and kept won. It can be lost after you have won it — if you are careless or negligent or indifferent.
Europe today is hungry. I am not talking about Germans. I am talking about the people of the countries which were overrun and devastated by the Germans, and particularly about the people of Western Europe. Many of them lack clothes and fuel and tools and shelter and raw materials. They lack the means to restore their cities and their factories.
As the winter comes on, the distress will increase. Unless we do what we can to help, we may lose next winter what we won at such terrible cost last spring. Desperate men are liable to destroy the structure of their society to find in the wreckage some substitute for hope. If we let Europe go cold and hungry, we may lose some of the foundations of order on which the hope for worldwide peace must rest.
We must help to the limits of our strength. And we will.

“We must leave our mark on life while we have it in our power.”

Debating Edward Teller, in The Nuclear Bomb Tests...Is Fallout Overrated? : Fallout and Disarmament KQED-TV, San Francisco http://osulibrary.oregonstate.edu/specialcollections/coll/pauling/peace/papers/1958p2.1.html (20 February 1958).
1940s-1960s
Context: We must not have a Nuclear war. We must begin to solve international disputes by the application of man's power of reason in a way that is worthy of the dignity of man. We must solve them by arbitration, negotiation, and the development of international law, the making of international agreements that will do justice to all nations and to all peoples and will benefit all nations and to all people. Now is the time to start.

Fifth annual Message http://avalon.law.yale.edu/18th_century/washs05.asp (3 December 1793)
1790s
Source: The Writings of George Washington from the Original Manuscript Sources 1745-1799 Volume 39 (General Index O-Z List of Letters) - Leather Bound

"The One Un-American Act," Speech to the Author's Guild Council in New York, on receiving the 1951 Lauterbach Award
Other speeches and writings