A beautiful speech by John F. Kennedy, still vividly of actuality today :
"Too many of us think [that peace] is impossible. Too many think it is unreal. But that is a dangerous, defeatist belief. It leads to the conclusion that war is inevitable, that mankind is doomed, that we are gripped by forces we cannot control. We need not accept that view. Our problems are manmade ; therefore, they can be solved by man. And man can be as big as he wants. No problem of human destiny is beyond human beings. Man's reason and spirit have often solved the seemingly unsolvable, and we believe they can do it again. I am not referring to the absolute, infinite concept of universal peace and goodwill of which some fantasies and fanatics dream. I do not deny the value of hopes and dreams, but we merely invite discouragement and incredulity by making that our only and immediate goal.
Let us focus instead on a more pratical, more attainable peace, based not on a sudden revolution in human nature but on a gradual evolution in human institutions - on a series of concrete actions and effective agreements which are in the interest of all concerned. There is no single, simple key to this peace ; no grand or magic formula to be adopted by one or two powers. Genuine peace must be the product of many nations, the sum of many acts. It must be dynamic, not static, changing to meet the challenge of each new generation. For peace is a process - a way of solving problems.
So, let us not be blind of our differences - but let us also direct attention to our common interests and to means by which those differences can be resolved. And if we cannot end now our differences, at least we can help make the world safe for diversity. For, in the final analysis, our most basic common link is that we all inhabit this planet. We all breathe the same air. We all cherish our children's future. And we are all mortal."
John F. Kennedy, Peace Address at American University, June 1963, when nuclear war was threatening to explode after the failed CIA-led invasion of Cuba in 1961, and the subsequent positioning of nuclear weapons in Cuba by the Soviet Union in October 1962 (cited by Jeffrey Sachs, Common Wealth, Economics for a crowded planet, chapter "Common challenges, common wealth").