Just War

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(Redirected from The Just War Theory)

Just War refers to the concept of warfare as being justified, typically in accordance with a particular situation, or scenario, and expanded or supported by reference to doctrine, politics, tradition, or historical commentary. The just war tradition is not, however, a philosophical "method" for determining whether a war can be justified. Like every tradition, the just war tradition includes a variety of thinkers who advocated different ways of employing shared concepts (such as just cause, good intentions, proportionality, and discrimination) for purposes of ethical reflection and judgment about the use of arms. The concept of just war has not been universally accepted, nor has the application of criteria defining just war been easy to apply in practice. There have been numerous occasions in history, however, when wars were fought for just causes, and which advanced human society in a beneficial direction. Ultimately, though, humankind must move beyond the age of resolving differences through acts of violence, and establish a world in which war no longer exists.


The Just War tradition is, first of all, a set of criteria that act as an aid to determining whether or not resorting to arms is the morally correct step. Just War theory promotes the view that war is "just" (in accordance with the interests of justice), given satisfactory conditions. As "conditions" tend to be variable, open to interpretation, and otherwise subject to political obfuscation, the concept of Just War itself, even apart from any specific formulated doctrines, is controversial.

The idea that resorting to war can be just only under certain conditions goes back at least to Cicero. While proponents claim that the identification of criteria to delineate just war is based on a long and successful tradition, critics claim the application of "Just War" is only relativistic, and directly contradicts more universal philosophical traditions such as the "Ethic of reciprocity," also known as the Golden Rule.

Just War theorists

  • Cicero (106 B.C.E.-43 B.C.E.) grew up in atmosphere of Civil War, and wrote on the justice of beginning a war.
  • Augustine of Hippo (354-430) advocated use of force on the Donatists: "Why … should not the Church use force in compelling her lost sons to return, if the lost sons compelled others to their destruction?"
  • Stanislaw of Skarbimierz (1360-1431) spoke of just war as a human rights issue.
  • Hugo Grotius (1583-1645) argued that all nations are bound by the principles of natural law in wars.
  • Baron von Pufendorf (1632-1694) disputed Hobbes' belief that the natural state of man was war, arguing it should be entered infrequently.
  • Emerich de Vattel (1714-1767) focused on the international diplomacy side of just war.
  • Immanuel Kant (1724-1804) wrote on the acceptable conditions for ending a war. Notably believed in constitutional republics.
  • Reinhold Niebuhr (1892-1971) was a key contributor to Christian Realism, which is a critique of pacifism. He advocated the use of force during World War II.
  • Michael Walzer (1935-) wrote on the importance of ethics in wartime, rejecting pacifism.
  • Brian Orend (1970-) focuses mainly on the period following wars and the treatment of losers.

Though each of these thinkers worked in distinctive areas of Just War theory, all believed that war could be considered just, given the right conditions. None could be considered pacifists.

Alternative theories

There have been several theories that have challenged Just War theory. These alternative theories include militarism, realism, absolutism, and pacifism. Also, some have claimed that the Just War theory is impractical in real-war situations.


Militarism is the belief that war is not inherently bad, but rather can be a beneficial aspect of society. Therefore, it is not necessary to distinguish "just wars" from other instances of warfare.


Proponents of Realism argue that moral concepts should never prescribe, nor circumscribe, a state's behavior. Instead, a state should place an emphasis on state security and self-interest. One form of realism, descriptive realism, proposes that states cannot act morally, while prescriptive realism argues that the motivating factor for a state is self-interest. In this view, the state is not subject to the same moral or ethical constraints as individuals or groups within a society. Thus, the issues of justice do not apply. War between states, just or unjust, may or may not occur, and should incur no judgment.


Absolutism holds that there are various ethical rules that are, as the name implies, absolute. Breaking such moral rules is never legitimate and therefore is always unjustifiable. In this case, there is no circumstance under which war, if it involves the breaking of ethical rules, can be considered a form of justice. The philosopher Thomas Nagel is a well known supporter of this view, having defended it in his essay, War and Massacre.


Pacifism is the belief that war of any kind is morally unjust. Pacifists extend humanitarian concern not just to enemy civilians but also to combatants, especially conscripts.[1]


The Just War tradition addresses the morality of the use of force in two parts: When it is right to resort to armed force (the concern of jus ad bellum) and what is acceptable in using such force (the concern of jus in bello).[2] In more recent years, a third category, Jus post bellum, has been added, which governs the justice of war termination and peace agreements, as well as the trying of war criminals.

Beginning a Just War: Jus ad bellum

In modern language, these rules hold that to be just, a war must meet the following criteria before using force (Jus ad bellum):

There must be Just Cause. Force may be used only to correct a grave public evil, such as a massive violation of the basic rights of whole populations, or in defense. Saint Augustine categorized just cause into three elements that justified warfare: Defending against an external attack, recapturing things taken, and punishing people who have done wrong.

War must seek Comparative Justice. While there may be rights and wrongs on all sides of a conflict, to override the presumption against the use of force, the injustice suffered by one party must significantly outweigh that suffered by the other.

Only duly constituted public authorities, known as Legitimate Authority, may use deadly force or wage war.

Force may be used only in a truly just cause, known as Right Intention, and solely for that purpose. Correcting a suffered wrong is considered a right intention, while material gain or maintaining economies is not.

There must be a high Probability of Success. Arms may not be used in a futile cause or in a case where disproportionate measures are required to achieve success.

Proportionality must hold. The overall destruction expected from the use of force must be outweighed by the good to be achieved.[3]

Finally, force may be used only as a Last Resort, after all peaceful and viable alternatives have been seriously tried and exhausted.

Note that these are only the most typical conditions cited by just war theorists; some (such as Brian Orend) omit Comparative Justice, seeing it as fertile ground for exploitation by bellicose regimes.

Conducting a Just War: Jus in bello

Once war has begun, Just War theory also directs how combatants are to act (Jus in bello):

Just War conduct should be governed by the principle of discrimination. The acts of war should be directed towards those responsible for the wrongs and not towards civilians. The prohibited acts include bombing civilian residential areas that include no military target, and committing acts of terrorism or reprisal against ordinary civilians. Some believe that this rule forbids "weapons of mass destruction" of any kind (such as the use of an atomic bomb) for any reason.

Combatants should adhere to the idea of proportionality. The force used must be proportional to the wrong endured, and to the possible good that may come. The more disproportional the number of collateral civilian deaths, the more suspect will be the sincerity of a belligerent nation's claim to the justness of a war it initiated.

Combatants should seek to use minimum force. This principle is meant to limit excessive and unnecessary death and destruction. It is different from proportionality because the amount of force proportionate to the goal of the mission might exceed the amount of force necessary to accomplish that mission.

Torture, of combatants or non-combatants, is forbidden in just war, and prisoners of war must be treated respectfully.

Ending a war: Jus Post Bellum

A third category within Just War theory, Jus post bellum, concerns justice after a war, including peace treaties, reconstruction, war crimes trials, and war reparations. Orend, for instance, proposed the following principles:

A state may terminate a war if there has been a reasonable vindication of the rights that were violated in the first place, and if the aggressor is willing to negotiate the terms of surrender. These terms of surrender include a formal apology, compensations, war crimes trials, and perhaps rehabilitation.

A state must only terminate a war under the conditions agreed upon in the above criteria. Revenge is not permitted. The victor state must also be willing to apply the same level of objectivity and investigation into any war crimes its armed forces may have committed.

The terms of peace must be made by a legitimate authority, and the terms must be accepted by a legitimate authority.

The victor state is to differentiate between political and military leaders, and combatants and civilians. Punitive measures are to be limited to those directly responsible for the conflict.

Any terms of surrender must be proportional to the rights that were initially violated. Draconian measures, absolutionist crusades, and any attempt at denying the surrendered country the right to participate in the world community are not permitted.

Just War theory and real-war situations

In modern warfare, proportionality as prescribed in jus in bello can be difficult to achieve, due to the tactic of placing military targets within civilian areas. The criterion for proportionality uses the concept of "double effect," that is, one may undertake military operations aimed at legitimate objectives or targets, despite the operation having foreseeable negative consequences, such as civilian casualties. Essentially, the negative consequences must be proportionate to the military gain. Theorists within the Just War tradition would accept that there is a threshold beyond which the negative consequences outweigh any other considerations, even the danger of defeat.

Proponents of realism would suggest that in a Total war it can be difficult to distinguish between a combatant and a civilian. It takes one pilot to fly a fighter jet, but it takes thousands of civilian man-hours to produce it and keep it operational. This argument is used to assert the principle of discrimination does not apply and significant enemy non-combatant casualties should be tolerated. This argument has been widely used to justify the atomic bombing of Hiroshima and Nagasaki[4] in World War II.

Revolution and Civil War

Just War theory states that a just war must have just authority. To the extent that this is interpreted as a legitimate government this leaves little room for revolutionary war or civil war, in which an illegitimate entity may declare war for reasons that fit the remaining criteria of Just War theory. This is less of a problem if the "just authority" is widely interpreted as "the will of the people." Certain types of civil war are specifically mentioned in Article 1, paragraph 4 of the 1977 Additional Protocols of the Geneva Convention of 1949, as covered by the international provisions of the Geneva Conventions, namely those "… in which peoples are fighting against colonial domination and alien occupation and against racist regimes …" this gives those fighting against such states the same status under international law and "just authority" as a legitimate government.


In the run up to the 2003 invasion of Iraq, the question as to whether it was a just war was posed. Many on both sides of the debate framed their arguments in terms of the Just War, coming to quite different conclusions because they put different interpretations on how the just war criteria should be applied. Supporters of the war tended to accept the United States' position that the enforcement of United Nations resolutions was sufficient authority or that the U.S. president, as a sovereign ruler, could count as legitimate authority. Opponents of the war tended to interpret legitimate authority as requiring a specific UN Security Council resolution.[5] Nelson Mandela was one who indicated this view, suggesting the U.S. position was effectively "if you are afraid of a veto in the Security Council, you can go outside and take action and violate the sovereignty of other countries."[6]


While the United States has been criticized harshly for its war in Iraq, the world community responded equally harshly when the United States, France, and others in the United Nations failed to act during the Rwandan Genocide in 1994. Around 1 million ethnic Tutsis are thought to have been killed. The United Nations established the United Nations Assistance Mission for Rwanda, but did not give its soldiers authority to enter into conflict except in self-defense. The UN also ignored reports of Hutu militias gathering weapons. Failure to act led to the veto of a second five year term as Secretary General of the UN for Boutros Boutros-Ghali. Just War theorists would argue that in such a clear case of genocide, it is the responsibility of powerful nations to intervene.


While the United States and the United Nations failed to act in Rwanda, NATO, led by the United States, took decisive action against culling of people in Kosovo under the rule of the Serbian leader Slobodan Milosevic. Milosevic's actions were the reaction to some ethnic Albanians guerrilla attacks on Serbian police. The Serbian reaction eventually turned into a slaughter of ethnic Albanians. The United States intervened and drove Milosevic from power.

While this action would generally be considered valid under Just War thinking, some suggested that a major factor in leading the U.S. president Bill Clinton to intervene was to distract from political scandal.

World War II

Just War Theory can also be applied to World War II, which serves as a good example, especially because many writers on the subject of Just War lived through this war. Reinhold Niebuhr is one such example, who advocated the Allies' use of force against the Axis nations in World War II. He rejected pacifist policies of appeasement that led to the Nazi occupation of what was then Czechoslovakia.

Debate is still possible over whether or not Hitler's unjustified blitzkrieg against Czechoslovakia and Poland justified declarations of war on Germany by other nations such as Great Britain and France. However, knowledge of the Holocaust provides valid motivation for entering the war. World War II also provides a good example of Jus Post Bellum, as members of the Axis were made to pay reparations to those countries affected by the war.

Just War today and in the future

The union of the nations of the world in global bodies such as the United Nations, the WTO, and NATO gives more prominence to the issue of just wars, as the global community debates intervention in more and more situations. Criticism of the actions in Iraq of the coalition led by the United States without UN approval show that the concept of just war is a global, rather than domestic issue, to be decided on the worldwide stage.

In the future, though, with the advance in globalization, as well as continuing increase in the number of countries and organizations possessing the means to bring about massive population and environmental destruction, the issue of just war should become a thing of the past. The only solution for the future of humankind will not be to engage in just wars, but rather to achieve a world in which warfare is no longer necessary, even as a last resort.


  1. The Manifesto, Manifesto Against Conscription and the Military System.
  2. James Turner Johnson, Just Cause Revisited. Retrieved March 20, 2008.
  3. www.usccb.org, Excerpts from The Harvest of Justice Is Sown in Peace. Retrieved March 20, 2008.
  4. John A. Siemes, The Atomic Bombings of Hiroshima and Nagasaki:Eyewitness Account 1996-2005. Retrieved March 20, 2008.
  5. United For Peace, United States Conference of Catholic Bishops Statement on Iraq.
  6. www.ilaam.net, Nelson Mandela: The U.S.A. Is a Threat to World Peace. Retrieved March 20, 2008.

ISBN links support NWE through referral fees

  • Charles, Daryl J. 2005. Between Pacifism and Jihad: Just War and Christian Tradition. InterVarsity Press. ISBN 0830827722
  • Heindel, Max. 1990. The Rosicrucian Philosophy in Questions and Answers—Volume II. Rosicrucian Fellowship. ISBN 0-911274-90-1
  • Small, Brad. Thomas Aquinas "The Just War Theory. The Lincoln-Douglas Great Philosopher Library Series.

External Links

All links retrieved October 4, 2022.


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