“But now that war has become seemingly total and seemingly permanent, the free sport of kings has become the forced and internecine business of people, and diplomatic codes of honor between nations have collapsed. Peace is no longer serious; only war is serious. Every man and every nation is either friend or foe, and the idea of enmity becomes mechanical, massive, and without genuine passion. When virtually all negotiation aimed at peaceful agreement is likely to be seen as 'appeasement,' if not treason, the active role of the diplomat becomes meaningless; for diplomacy becomes merely a prelude to war or an interlude between wars, and in such a context the diplomat is replaced by the warlord……In other words 'the morale of the State Department is so broken that its finest men flee from it, and advise others to flee.”

Fourteen Points https://www.marxists.org/archive/mcmanus/articles/points.htm, Halifax Division of the Socialist Labour Party, (1918)

Foreword (1984) to The Market for Liberty (1970)

Nobel lecture (2001)
Context: In a world filled with weapons of war and all too often words of war, the Nobel Committee has become a vital agent for peace. Sadly, a prize for peace is a rarity in this world. Most nations have monuments or memorials to war, bronze salutations to heroic battles, archways of triumph. But peace has no parade, no pantheon of victory.
What it does have is the Nobel Prize — a statement of hope and courage with unique resonance and authority. Only by understanding and addressing the needs of individuals for peace, for dignity, and for security can we at the United Nations hope to live up to the honour conferred today, and fulfil the vision of our founders. This is the broad mission of peace that United Nations staff members carry out every day in every part of the world.

1930s, Quarantine Speech (1937)
Context: There is a solidarity and interdependence about the modern world, both technically and morally, which makes it impossible for any nation completely to isolate itself from economic and political upheavals in the rest of the world, especially when such upheavals appear to be spreading and not declining. There can be no stability or peace either within nations or between nations except under laws and moral standards adhered to by all. International anarchy destroys every foundation for peace. It jeopardizes either the immediate or the future security of every nation, large or small. It is, therefore, a matter of vital interest and concern to the people of the United States that the sanctity of international treaties and the maintenance of international morality be restored.

Alexander Rich and John R. Platt (1966) "How to Keep the Peace" in: Bulletin of the Atomic Scientists. April 1966. p. 14

Steps Toward Inner Peace : Harmonious Principles for Human Living http://www.peacepilgrim.net/FoPP/htm/steps.htm
Context: In order for the world to become peaceful, people must become more peaceful. Among mature people war would not be a problem — it would be impossible. In their immaturity people want, at the same time, peace and the things which make war. However, people can mature just as children grow up. Yes, our institutions and our leaders reflect our immaturity, but as we mature we will elect better leaders and set up better institutions. It always comes back to the thing so many of us wish to avoid: working to improve ourselves.

The Power Elite (1956)

Speech on the Line of the Perdido, Senate (25 December 1810).

On the Irrepressible Conflict (1858)
Context: The Union is a confederation of States. But in another aspect the United States constitute only one nation. Increase of population, which is filling the States out to their very borders, together with a new and extended network of railroads and other avenues, and an internal commerce which daily becomes more intimate, is rapidly bringing the States into a higher and more perfect social unity or consolidation. Thus, these antagonistic systems are continually coming into closer contact, and collision results.
Shall I tell you what this collision means? They who think that it is accidental, unnecessary, the work of interested or fanatical agitators, and therefore ephemeral, mistake the case altogether. It is an irrepressible conflict between opposing and enduring forces, and it means that the United States must and will, sooner or later, become either entirely a slaveholding nation, or entirely a free-labor nation.