Just war theory is the attempt to distinguish between justifiable and unjustifiable uses of organized armed forces.
- Pax melior est quam iustissimum bellum.
- Translation: Peace is better than the most just war.
- .מלחמת שלום הגליל היתה מהמוצדקות ביותר במלחמות ישראל
- We must not let what happened lead to a deepening of divisions. Religion must never be used as a reason for conflict. [...] With all my heart I beg God to keep the world in peace. From this place, I invite both Christians and Muslims to raise an intense prayer to the One, almighty God whose children we all are, that the supreme good of peace may reign in the world.
- Pope's spokesman Dr. Joaqun Navarro-Valls: ...the pope believes that the extremists directly responsible for the attacks on the United States could and should be distinguished from the wider threat of Islamic fundamentalism and that any response should be limited to punishing the guilty.
- Pope John Paul II, Astana, Kazakhstan, September 23, 2001 
- The war in Afghanistan against apocalyptic terrorism qualifies in my understanding as the first truly just war since World War II.
- Defining a Just War, by Richard Falk, October 11, 2001
- I say: NO TO WAR! War is not always inevitable. It is always a defeat for humanity. International law, honest dialogue, solidarity between states, the noble exercise of diplomacy; these are methods worthy of individuals and nations in resolving their differences. I say this as I think of those who still place their trust in nuclear weapons, and as I think of the all too numerous conflicts which continue to hold hostage our brothers and sisters in humanity. Bethlehem reminds us of the unresolved crisis in the Middle East, where two peoples, Israeli and Palestinian, are called to live side by side, equally free and sovereign, in mutual respect. Faced with the constant degeneration of the crisis in the Middle East, I say to you that the solution will never be imposed by recourse to terrorism or armed conflict, as if military victories could be the solution. And what are we to say about the threat of a war which could strike the people of Iraq, the land of the Prophets, a people already sorely tried by more than 12 years of embargo? War is never just another means that one can choose to employ for settling differences between nations. As the charter of the United Nations Organisation and international law itself remind us, war cannot be decided upon, even when it is a matter of ensuring the common good, except as the very last option and in accordance with very strict conditions, without ignoring the consequences for the civilian population both during and after the military operations.
- When war, as in these days in Iraq, threatens the fate of humanity, it is ever more urgent to proclaim, with a strong and decisive voice, that only peace is the road to follow to construct a more just and united society. Violence and arms can never resolve the problems of men.
- Constantine was converted to Christianity by a vision that came to him on the eve of the battle of Milvian Bridge: "He saw with his own eyes, up in the sky and resting over the sun, a cross-shaped trophy formed from light, and a text attached to it which said, 'By this sign, conquer' ". Soon the cross would morph from being a hated symbol of Roman brutality into the universally recognizable logo of the Holy Roman Empire. Within a century, St Augustine would develop the novel idea of just war, trimming the church's originally pacifist message to the needs of the imperial war machine.
- Empires prefer a baby and the cross to the adult Jesus, by Giles Fraser, December 24, 2004
- Every decision to launch a war, even if it is the most justified and clear decision, is never easy. [...] It should not be utilized in the political race of those who wish to rise to power even at the price of baseless self-destruction, which lacks logic and boundaries – all this around a war which was the most justified.
- Ron Paul: I strongly believe that there is a Christian doctrine of just war. [..] Christ came here for spiritual reasons, not secular war and boundaries and geography. And yet, we are now dedicating so much of our aggressive activity in the name of God, but God, he is the Prince of Peace. That is what I see from my God and through Christ. I vote for peace.
Sam Brownback: I vote for peace, too. But I also vote for the protection of life, and I vote for the strength of America, and I vote for our place in the world. This is a key country, and it's a country that is standing up to Islamic fascism, and it's a country that is standing up for the rights of individuals, and I think there is a just war that is going on in Iraq. --Values Voter Presidential Debate, September 17, 2007  
- There are two rules of war that have not yet been invalidated by the new world order. The first rule is that the belligerent nation must be fairly sure that its actions will make things better; the second rule is that the belligerent nation must be more or less certain that its actions won't make things worse.
- Martin Amis, "The Palace of the End", The Guardian, 4 March 2003