“We have carried our quest for peace to many nations and peoples because we share this planet with others whose future, in large measure, is tied to our own action, and whose counsel is necessary to our own hopes. We have found understanding and support. And we know they wait with us tonight for some response that could lead to peace. I wish tonight that I could give you a blueprint for the course of this conflict over the coming months, but we just cannot know what the future may require. We may have to face long, hard combat or a long, hard conference, or even both at once. Until peace comes, or if it does not come, our course is clear. We will act as we must to help protect the independence of the valiant people of South Vietnam. We will strive to limit the conflict, for we wish neither increased destruction nor do we want to invite increased danger. But we will give our fighting men what they must have: every gun, and every dollar, and every decision—whatever the cost or whatever the challenge. And we will continue to help the people of South Vietnam care for those that are ravaged by battle, create progress in the villages, and carry forward the healing hopes of peace as best they can amidst the uncertain terrors of war. And let me be absolutely clear: The days may become months, and the months may become years, but we will stay as long as aggression commands us to battle. There may be some who do not want peace, whose ambitions stretch so far that war in Vietnam is but a welcome and convenient episode in an immense design to subdue history to their will. But for others it must now be clear—the choice is not between peace and victory, it lies between peace and the ravages of a conflict from which they can only lose.”

1990s, A Distinctly American Internationalism (November 1999)
Context: Some have tried to pose a choice between American ideals and American interests — between who we are and how we act. But the choice is false. America, by decision and destiny, promotes political freedom — and gains the most when democracy advances. America believes in free markets and free trade — and benefits most when markets are opened. America is a peaceful power — and gains the greatest dividend from democratic stability. Precisely because we have no territorial objectives, our gains are not measured in the losses of others. They are counted in the conflicts we avert, the prosperity we share and the peace we extend.

1970s, Second Inaugural Address (1973)

Undated
Source: Wikipedia article http://en.wikipedia.org/wiki/Prem_Rawat.

1920s, Nationalism and Americanism (1920)

Speech following the Minnesota primary (3 June 2008) http://www.cnn.com/2008/POLITICS/06/03/obama.speech/index.html
2008

2011, Address on interventions in Libya (March 2011)
Context: For generations, we have done the hard work of protecting our own people, as well as millions around the globe. We have done so because we know that our own future is safer, our own future is brighter, if more of mankind can live with the bright light of freedom and dignity. 
Tonight, let us give thanks for the Americans who are serving through these trying times, and the coalition that is carrying our effort forward. And let us look to the future with confidence and hope not only for our own country, but for all those yearning for freedom around the world.

Interview with Monte Leach, Peace is possible, peace is inevitable, Share International (July 2003) http://www.share-international.org/magazine/old_issues/2003/july_03.htm#voice.

1990s, A Period of Consequences (September 1999)

Source: Sons of Destiny