“We cannot have general peace for the asking, or by the mere arrangements of a peace conference. It cannot be pieeed together out of individual understandings between powerful states. All the parties to this war must join in the settlement of every issue anywhere involved in it; beeause what we are seeing is a peace that we can all unite to guarantee and maintain and every item of it must be submitted to the common judgment whether it be right and fair, an act of justice, rather than a bargain between sovereigns.”

1990s, Inaugural celebration address (1994)
Context: We are both humbled and elevated by the honour and privilege that you, the people of South Africa, have bestowed on us, as the first President of a united, democratic, non-racial and non-sexist government.
We understand it still that there is no easy road to freedom
We know it well that none of us acting alone can achieve success.
We must therefore act together as a united people, for national reconciliation, for nation building, for the birth of a new world.
Let there be justice for all.
Let there be peace for all.

2013, Eulogy of Nelson Mandela (December 2013)
Context: The struggles that follow the victory of formal equality or universal franchise may not be as filled with drama and moral clarity as those that came before, but they are no less important. For around the world today, we still see children suffering from hunger and disease. We still see run-down schools. We still see young people without prospects for the future. Around the world today, men and women are still imprisoned for their political beliefs, and are still persecuted for what they look like, and how they worship, and who they love. That is happening today. And so we, too, must act on behalf of justice. We, too, must act on behalf of peace. There are too many people who happily embrace Madiba’s legacy of racial reconciliation, but passionately resist even modest reforms that would challenge chronic poverty and growing inequality. There are too many leaders who claim solidarity with Madiba’s struggle for freedom, but do not tolerate dissent from their own people. And there are too many of us on the sidelines, comfortable in complacency or cynicism when our voices must be heard.

Ariel Sharon. "I an for lasting peace." at New York Post Forum, November 13, 2000, cited at Freeman.org http://www.freeman.org/m_online/dec00/sharon.htm, November 14, 2000.
2000s

1860s, 1864, Letter to the City of Atlanta (September 1864)

1920s, Ways to Peace (1926)

1960s, The Quest for Peace and Justice (1964)
Context: We will not build a peaceful world by following a negative path. It is not enough to say "We must not wage war." It is necessary to love peace and sacrifice for it. We must concentrate not merely on the negative expulsion of war, but on the positive affirmation of peace. There is a fascinating little story that is preserved for us in Greek literature about Ulysses and the Sirens. The Sirens had the ability to sing so sweetly that sailors could not resist steering toward their island. Many ships were lured upon the rocks, and men forgot home, duty, and honor as they flung themselves into the sea to be embraced by arms that drew them down to death. Ulysses, determined not to be lured by the Sirens, first decided to tie himself tightly to the mast of his boat, and his crew stuffed their ears with wax. But finally he and his crew learned a better way to save themselves: they took on board the beautiful singer Orpheus whose melodies were sweeter than the music of the Sirens. When Orpheus sang, who bothered to listen to the Sirens? So we must fix our vision not merely on the negative expulsion of war, but upon the positive affirmation of peace. We must see that peace represents a sweeter music, a cosmic melody that is far superior to the discords of war.

About international relationships. Parliamentary speech on November 26, 1940.
International relationships

1970s, Remarks on Being Reelected (1972)

Address to the United Nations (1964)