Just war

Definition & Introduction

Just war is warfare that is justified by a moral or legal tradition.

Just war theory presumes that there are legitimate uses of war but also sets moral boundaries on the waging of war. It deals with two fundamental questions concerning the ethics of war and peace: When is it morally and legally justified to go to war? What moral principles should we follow during war? Jus ad bellum (moral justifications for going to war) requires that the cause for war is just; the right authority makes the decision; the decision is made with the right intention of bringing about peace; the war is a last resort; the overall evil of the war does not outweigh the good. Jus in bello (moral principles to follow during war) governs the treatment of prisoners; requires the protection of civilians, and prohibits the disproportionate use of force. A third part of just war theory is jus post bellum, denoting justice after war.

The historical aspect of just war, also referred to as the just war tradition, represents the historical rules, such as the Geneva Convention, that have been applied to wars. Ethical theorists of international relations must consider the philosophical coherence of international agreements and reflect upon the circumstances that legitimize the waging of war.

Featured Reading

Stanford Encyclopedia of Philosophy: War

"Some reject the very idea of the morality of war. Of those, some deny that morality applies at all once the guns strike up; for others, no plausible moral theory could license the exceptional horrors of war."

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New Rules for War?

Originally penned in 2004, Carnegie Council President Joel Rosenthal reflects on the United States' pursuit of its war on terror.

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Just War Theory: A Reappraisal

The just war tradition has provided one of the most beguiling frameworks for the question of when it is right to go to war, and how war ought to be conducted.

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Essential Resources on Ethics in War

Carnegie Council President Joel Rosenthal compiles a selection of materials on ethics in war.

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Discussion Questions

1. What distinguishes preemptive war from preventive war? Consider the case of Germany in World War II and answer the question: Is regime change ever a just cause of war?

2. The international community has been unable to come together under the banner of just war to stop genocide in the Sudan. What political factors constrain the waging of a just war? What obligation does the international community have to declare just war? Compare the Sudanese case to that of Rwanda, Iraq, and Kosovo. What similarities/differences are there between these cases and how do they relate to the concept of just war?

3. The 2006 mid-term election sparked contentious debate on American's role in Iraq, particularly with regards to America's role jus post bellum. What responsibility does the United States have in the reconstruction of Iraq?