“If we want to save the planet earth, to save life and humanity, we have a duty to put an end to the capitalist system. Unless we put an end to the capitalist system, it is impossible to imagine that there will be equality and justice on this planet earth. This is why I believe that it is important to put an end to the exploitation of human beings and to the pillage of natural resources, to put an end to destructive wars for markets and raw materials, to the plundering of energy, particularly fossil fuels, to the excessive consumption of goods and to the accumulation of waste. The capitalist system only allows us to heap up waste. I would like to propose that the trillions of money earmarked for war should be channelled to make good the damage to the environment, to make reparations to the earth.”

Source: Blackshirts and Reds (1997), p. 155

1950s, The Russell-Einstein Manifesto (1955)
Context: Here, then, is the problem which we present to you, stark and dreadful and inescapable: Shall we put an end to the human race; or shall mankind renounce war? People will not face this alternative because it is so difficult to abolish war.
The abolition of war will demand distasteful limitations of national sovereignty. But what perhaps impedes understanding of the situation more than anything else is that the term "mankind" feels vague and abstract. People scarcely realize in imagination that the danger is to themselves and their children and their grandchildren, and not only to a dimly apprehended humanity. They can scarcely bring themselves to grasp that they, individually, and those whom they love are in imminent danger of perishing agonizingly. And so they hope that perhaps war may be allowed to continue provided modern weapons are prohibited.
This hope is illusory. Whatever agreements not to use H-bombs had been reached in time of peace, they would no longer be considered binding in time of war, and both sides would set to work to manufacture H-bombs as soon as war broke out, for, if one side manufactured the bombs and the other did not, the side that manufactured them would inevitably be victorious.

No Compromise – No Political Trading (1899)

1961, UN speech
Context: Mankind must put an end to war — or war will put an end to mankind.
So let us here resolve that Dag Hammarskjold did not live, or die, in vain. Let us call a truce to terror. Let us invoke the blessings of peace. And as we build an international capacity to keep peace, let us join in dismantling the national capacity to wage war.
Context: We meet in an hour of grief and challenge. Dag Hammarskjold is dead. But the United Nations lives. His tragedy is deep in our hearts, but the task for which he died is at the top of our agenda. A noble servant of peace is gone. But the quest for peace lies before us.
The problem is not the death of one man — the problem is the life of this organization. It will either grow to meet the challenges of our age, or it will be gone with the wind, without influence, without force, without respect. Were we to let it die, to enfeeble its vigor, to cripple its powers, we would condemn our future. For in the development of this organization rests the only true alternative to war — and war appeals no longer as a rational alternative. Unconditional war can no longer lead to unconditional victory. It can no longer serve to settle disputes. It can no longer concern the great powers alone. For a nuclear disaster, spread by wind and water and fear, could well engulf the great and the small, the rich and the poor, the committed and the uncommitted alike. Mankind must put an end to war — or war will put an end to mankind.
So let us here resolve that Dag Hammarskjold did not live, or die, in vain. Let us call a truce to terror. Let us invoke the blessings of peace. And as we build an international capacity to keep peace, let us join in dismantling the national capacity to wage war.

Afro-Asian Conference (1965)

I Think I'll Sit This One Out (1939)
Context: Socialism may be all right when men are fit to be socialists. The way may be hard and slow, but until we take it we shall find that the so-called Socialist state degenerates and Fascism as rapidly as the pacifist with warm hearts to generate into militarists with fevered brows.
Marxism, like fascism and capitalism is materialism. The love of material goods above all others is as animal as of love of war. The love of justice above material goods must save us in the end it saved we may be.

40th anniversary of the Apollo 11 landing (2009)

Twitter, https://twitter.com/TulsiGabbard/ (4 March 2019)
Twitter account, March 2019

Interview with Al Jazeera (25 May 2018)