“Just war” principles seek to transform war and peace into moral questions, to move international relations beyond the “realist” conception classically expressed in The Peloponnesian War by the fifth-century BCE Greek historian Thucydides. A realist conceives of wars as a normal if undesirable fact of international relations, a matter of irreconcilable national interests or policies in which the “royal prerogative,” the authority to decide for war or for peace, is an inherent sovereign power of governments. The realist is dubious about the contention that, in a world order still characterized by anarchy, war can be reconceived at its root as a moral matter, although moral considerations can certainly be compelling in one way or another. To a realist, wars have occurred in history because, as the French philosopher Jean-Jacques Rousseau (1712–1778) said, there is nothing adequate to stop them. To a just war advocate, on the other hand, realism is far from irrelevant, but it is only the beginning of civilizing, that is, justifying and limiting humankind’s most damaging activity.
But just war principles are not at all the same as pacifism. Just war theorists argue that all war is in some sense evil, yet some wars are justified. A universal presumption against war, let alone a national policy of nonviolence, would be not only self-destructive but immoral because sometimes war is both necessary and right, particularly wars of self-defense against aggression.
A just war is a right use of force founded in the moral responsibility of a government for the political community as a whole. In just war thinking, the “Westphalian system” launched in 1648 was based on a great mistake. This system refers to the modern international order consisting of sovereign nation-states, established by the European Treaty of Westphalia in 1648. Sovereignty was defined in purely procedural terms, implying that whoever successfully controls a territory should be accepted internationally as sovereign in it. The result was that, until quite recently, dictators used the legal principle of national sovereignty as a shield to protect themselves while tyrannizing their own people. Just war principles attempt to inject the concept of sovereignty with substantive moral meaning.
The just war idea has roots in ancient Israel and was first conceptualized in Catholic tradition by Augustine (354–430 CE), the bishop of Hippo, in The City of God. The Italian natural law philosopher Thomas Aquinas (1225–1274) gave the classic statement of just war principles in Summa Theologica. According to Thomas Aquinas, a just war is defined by two sets of criteria: whether the cause is just (jus ad bellum ) and whether the methods of combat are just (jus in bello ). Just war is thus an issue of both means and ends: A just war may be fought unjustly and vice versa. While the principles are fairly clear (although not entirely without ambiguity), controversy is inevitable in judging any particular case, a theme particularly well developed in the work of the influential American just war theorist Michael Walzer (2000).
Walzer argued that a just cause for war exists if five criteria are met. (1) The intention must be right, meaning a war must be waged either in self-defense against aggression or it must be an international intervention to aid another people victimized by egregious aggression. Since World War I (1914–1918), certain states (especially the United States) and international organizations (the United Nations, the North Atlantic Treaty Organization [NATO], and the European Union) have invoked a right to intervention on moral and humanitarian, as well as realist, terms. Since the 1990s, the international community, in the United Nations and outside it, has begun to codify not only a right to intervene but also a duty to do so—a “responsibility to protect” peoples in danger, a duty to reverse grave violations of human rights. (2) The decision to go to war must be made by a duly constituted sovereign, that is, a legitimate authority. (3) War must be a last resort, the ultima ratio, undertaken only after all diplomatic means have failed. (4) There must be a reasonable probability of success, the reason being to avoid futile damage. (5) The good to be achieved must clearly outweigh the harm to be done, the intrinsic evil aspect of even a just war.
In terms of the means of combat, a war is considered just if it meets two conditions. The principle of “discrimination” must be respected, that is, distinguishing insofar as possible between combatants and civilians, and strictly limiting the “double effect” or “collateral damage” of killing innocents while fighting. In addition, the principle of “proportionality” must be respected, meaning that damage inflicted must bear some reasonable relationship to the original aggression.
In retrospect, the catastrophic world wars and genocides of the twentieth century paradoxically emphasized both the continued relevance of realist international-relations thinking and the desirability of moving toward just war principles. For example, the Geneva Conventions on protection of prisoners of war and the prohibition of torture may be considered just war treaties. The Holocaust, the atomic bombings of the Japanese cities of Hiroshima and Nagasaki, and the firebombing of German and Japanese cities during World War II (1939–1945) have led to a widespread conclusion that genocide or the use of weapons of mass destruction can never be justified.
The American-led Gulf War of 1991 to reverse Saddam Hussein’s invasion and annexation of Kuwait, the European-American intervention in the Balkan wars of the 1990s, and the post-September 11, 2001, war in Afghanistan all were fought as just wars, that is, moral campaigns larger than the evident interest of the international community in reestablishing peace and security. There may be serious argument about whether or not any particular war is a just war (for example the American-led invasion of Iraq in 2003 to overthrow Saddam Hussein’s regime). But at the beginning of the twenty-first century it is evident that moral arguments about goals and methods of war are increasingly relevant in the real world of international relations, as opposed to realist Westphaliantype declarations of national interest or policy. This is fundamental moral progress, even as it is obvious that prudence remains the statesperson’s necessary virtue.
The new age of global-scale terrorist attacks has obvious relevance for just war thinking. On the other hand, evaluating the justice of terrorist campaigns, although it may seem simple, is no easy matter. Judgments are not intuitive and the results are a matter of sharp dispute in world politics in the early twenty-first century. While it is insufficient simply to say that “one man’s terrorist is another man’s freedom fighter,” distinctions can and must be made in the real world or else it is too easy to end up in a situation in which might, or the most effective propaganda, makes right. Gradually, as with other aspects of international law, such as outlawing torture and genocide, increasing consensus about terrorism across different kinds of states, cultures, religions, and world regions may emerge. One example of international agreement on a definition of terrorism is found in the 2004 United Nations report, “A More Secure World.”
Terrorist acts are a tactical means of waging war. In just war terms, terrorism is illegitimate and unjust in itself, no matter how much sympathy this form of fighting may inspire in a civilian population. However, it is important to remember that terrorist groups are unaffected by this, since they reject the customary international laws of war as such, invoking their own, usually religious conception of just war ends and means. Terrorist groups, especially the new phenomenon of global terrorist networks, willfully defy the principle of discrimination by intentionally targeting civilians on a wide scale in an attempt to instill destabilizing fear in governments and populations. There is a sharp difference, at least in principle, between the intentional killing of innocents and military action that kills or wounds civilians in spite of genuine attempts to limit such damage, generally called collateral damage. In just war theory, intentions are fundamental, and the fallacy of moral equivalence—that is, civilians killed are civilians killed, no matter what the circumstance—must be avoided.
On the other hand, the concept of collateral damage can be dangerous because it can become overly expansive. For example, in spite of rigorous attempts to limit the killing of civilians in certain ways, a given state’s overall military campaign against terrorism may involve collateral damage on such a scale, with a more or less hidden intent to terrorize a population and turn it against erstwhile popular terrorist groups (themselves fighting with unjust means), that the military campaign itself becomes state-sponsored terrorism. In other words, terrorism may be a weapon of duly constituted, sovereign authority.
Furthermore, a terrorist group may in fact be fighting for a just cause—for example, it may be a military wing of a national liberation movement seeking national sovereignty and independence against a colonialist foreign power, or one or both sides in a civil war. Success of a terrorist campaign in such a case will not be military victory; rather, its goal will be to demoralize the adversary’s military or political leadership or its home population to the extent that a negotiated compromise or even total withdrawal may result. In such a case, a terrorist campaign that historically was only one aspect of a successful struggle for national independence may be remembered differently than it would have been had the struggle been lost.
In any case, however, terrorist acts on any side remain in and of themselves unjust and illegitimate. It is wrong to take any innocent person’s life, whether or not it can be claimed that a just end is being served. It is a fallacy to contend flatly that “just war trumps unjust means.” At the same time, just war judgments must somehow recognize a situation in which a rebellion’s use of only just means will leave a population more or less defenseless against an even more unjust power—whether the latter is its own government or an outside power. In such a case, agreement might be reachable by saying that, as with war itself, all terrorism is evil but it is always justifiable to choose the lesser evil.
Altogether, just war principles are not—far from it—a single unified doctrine that will easily unite the world politically or could be easily codified in international law. They represent moral guidelines, extending long-established, basically pragmatic, realist laws of war. They constitute a broad set of standards continuing a secular struggle to justify war in human terms and to limit its damage, against which individual cases can be argued and measured. Again, just war thinking does not envisage the abolition of war, because sometimes war is not only necessary but right.
Perhaps the appropriate conclusion at this point is to say that just war thinking is simultaneously a beginning and a hope, above all if, as increasing numbers of thoughtful people agree, war is a cultural phenomenon rather than human fate. Cultural practices may evolve in response to circumstances. In any case, realism and prudence will remain, at least for some time, the necessary foundations of international policy in a world order still characterized by anarchy.
SEE ALSO Civil Wars; Law; Terrorism; Terrorists; War
Johnson, James Turner. 2005. Just War, As It Was, and Is. First Things 149 (2005): 14–24.
Walzer, Michael. 2000. Just and Unjust Wars: A Moral Argument with Historical Illustrations. 3rd ed. New York: Basic Books.
"Just War." International Encyclopedia of the Social Sciences. . Encyclopedia.com. (September 10, 2018). http://www.encyclopedia.com/social-sciences/applied-and-social-sciences-magazines/just-war
"Just War." International Encyclopedia of the Social Sciences. . Retrieved September 10, 2018 from Encyclopedia.com: http://www.encyclopedia.com/social-sciences/applied-and-social-sciences-magazines/just-war
Modern Language Association
The Chicago Manual of Style
American Psychological Association
As widely used, a term referring to any war between states that meets generally accepted international criteria of justification. The concept of just war invokes both political and theological ideology, as it promotes a peaceful resolution and coexistence between states, and the use of force or the invocation of armed conflict only under certain circumstances. It is not the same as, but is often confused with, the term jihad or "holy war," a Muslim religious justification for war.
The principle of a just war emerged early in the development of scholarly writings on international law. Under this view, a just war was a means of national self-help whereby a state attempted to enforce rights actually or allegedly based on international law. State practice from the eighteenth to the early part of the twentieth century generally rejected this distinction, however, as war became a legally permissible national policy to alter the existing rights of states, irrespective of the actual merits of the controversy.
Following world war i, diplomatic negotiations resulted in the General Treaty for the Renunciation of War, more commonly known as the kellogg-briand pact, signed in 1928. The signatory nations renounced war as a means to resolve international disputes promising instead to use peaceful methods.
The aims of the Kellogg-Briand Pact were adopted in the Charter of the united nations in 1945. Under the charter, the use or threat of force as an instrument of national policy was condemned, but nations were permitted to use force in individual or collective self-defense against an aggressor. The General Assembly of the United Nations has further defined aggression as armed force by a state against the sovereignty, territorial integrity, or political independence of another state, regardless of the reasons for the use of force. The Security Council is empowered to review the use of force, and therefore, to determine whether the relevant circumstances justify branding one nation as the aggressor and in violation of charter obligations. Under the modern view, a just war is one waged consistent with the Kellogg-Briand Pact and the Charter of the United Nations.
What has complicated the concept of just war in contemporary international relations is the emergence of "asymmetrical warfare." The term refers to conflict with parties or entities (such as international terrorist groups) who are neither officially connected with, nor owe allegiance to, any particular public authority or state. While these individuals or groups may be dependent upon clandestine assistance from states willing to help them secretly, they are not publicly responsible to them. Since contemplation of just war requires public authorities to act in their official capacities for the common good, that objective is frustrated by the lack of a discernible, clearly identifiable enemy state against which to act. As a result, the international community has attempted to unite in a common effort to declare war against terrorism in general as "just."
Johnson, James Turner. 2002. "Jihad and Just War." First Things 124.
Novak, Michael. 2003. "Asymmetrical Warfare & Just War." National Review online. Text of public lecture given on February 10 in Rome. Available online at <www.nationalreview.com/novak/novak021003.asp> (accessed August 13, 2003).
"Just War." West's Encyclopedia of American Law. . Encyclopedia.com. (September 10, 2018). http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/just-war
"Just War." West's Encyclopedia of American Law. . Retrieved September 10, 2018 from Encyclopedia.com: http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/just-war
Modern Language Association
The Chicago Manual of Style
American Psychological Association
In other religions, war can be regarded as ‘just’ (or at least as justifiable), but the criteria vary. In Islam and among Sikhs, the criteria are formal: see JIHĀD; DHARAM YUDH. In Indian-based religions, there is an overriding consideration of ahiṃsā (non-violence). Nevertheless, in the long cycles of rebirth, there will always be those whose obligation (dharma) it is to undertake warfare in certain circumstances (especially those of defence). This is the classic argument of Kṛṣṇa to Arjuna in the Bhagavad-gītā (it must clearly be the dharma of a kṣatriya to act as a warrior); but it is also found in Buddhism and among Jains. There is no religion in which the propriety of war in some circumstances is not admitted.
"Just war." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (September 10, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/just-war
"Just war." The Concise Oxford Dictionary of World Religions. . Retrieved September 10, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/just-war
Modern Language Association
The Chicago Manual of Style
American Psychological Association
The term just war refers to the major moral tradition of Western culture that deals with the justification and limitation of the use of force by public authority. Just war tradition has particular relevance for moral reflection about many scientific and technological developments related to military affairs.
Just war tradition can be traced back to Saint Augustine (354–430) in the fourth and fifth centuries and through him to the Old Testament and the ideas and practices of classical Greece and Rome. Augustine, however, did not write systematically or at length about the idea of just war; his treatment of these issues is found in passages about the use of force in works on various topics. A coherent, systematic body of thought and practice on just war did not emerge until the Middle Ages. The thought of Augustine and other earlier Christian writers was drawn together by the canonist Johannes Gratian, whose Decretum dates to the middle of the twelfth century. Two generations of canonists who built on Gratian's work, the Decretists and the Decretalists, took the development of the just war idea into the thirteenth century. In the second half of that century theologians, including most notably Thomas Aquinas (1224–1274), placed the canonical materials in an overarching theological framework that showed both a strong dependence on Augustine's thinking and a new effort to give ideas about just war a footing in natural law.
During the thirteenth century but more during the fourteenth and fifteenth centuries, secular factors began to reshape this canonical and theological concept into a broad cultural consensus. These factors were the growing study of Roman law, especially the idea of jus gentium (law of peoples or nations); the maturation of the chivalric code as a guide to the conduct in arms of the international brotherhood of knights; and increased reflection on the experience of governing found in works dealing with the characteristics of a good ruler.
By the end of the Hundred Years War in the mid-fifteenth century the resulting synthesis (seen particularly in writers such as the theologian and scholar Honoré Bonet [1340–1410] and the poet and historian Christine de Pisan [1363–1430]) had defined a cultural consensus in western Europe on the justified use of armed force and the restraints to be observed in using that force. This consensus included the major factors that continue to define the idea of a just war. From canon law and theology came the requirements that for a resort to armed force to be just it must be undertaken on the authority of a sovereign and for the public good; be for a just cause, defined as defending the common good, retaking that which had been taken wrongly, and punishing evil; and right intention, defined negatively as the avoidance of self-aggrandizement, bullying, implacable hatred, and so on, and positively as aiming to restore the peace that had been violated.
The chivalric code joined canon law to provide two kinds of restraint on the employment of force: noncombatant immunity, defined by lists of persons not normally involved in war and thus not to be subjected to direct harm in war, and limits on means, defined by efforts to ban certain weapons (specifically arrows and siege machines) as mala in se. The jus gentium and the growing consolidation of political authority reinforced these developments in useful ways: the former by placing them in a broader theoretical framework to define relationships among autonomous political communities and the latter by sovereigns' adoption of these rules both in the use of force to maintain public order and in warfare against external threats.
In this manner the just war tradition was passed to the modern era. Theological and secular theorists of the law of nations, including the theologian Francisco de Vitoria (1492–1596) in the sixteenth century and the jurist Hugo Grotius (1583–1645) in the seventeenth, placed the inherited just war tradition in the context of a general theory of international law based on natural law and the jus gentium. After Grotius and as a result of the international order created by the Peace of Westphalia (1648), emphasis on the former part of the tradition, by then called the jus ad bellum, began to be reduced as sovereigns' rights to use force were redefined as compétence de guerre at the same time that a new emphasis was placed on the restraints to be observed in the use of force, the jus in bello.
This has been the pattern of the development of the just war tradition during the modern period. Beginning in the 1860s with the work of Francis Lieber and the U.S. Army's General Orders No. 100 of 1863 and, at almost the same time, the international adoption of the First Geneva Convention, positive international law has played a major role in defining the just war jus in bello. Through much of the nineteenth century and continuing into the nuclear age, moral thought on war has focused on efforts to rule out recourse to armed force by states, in effect denying that a jus ad bellum, a justification of the resort to armed force, exists any longer, or severely restricting the terms of such justification. During this period, because of its concentration on eliminating war, moral thought effectively lost sight of the just war jus in bello. At the same time, however, the increasing codification of international law reframed the tradition's jus in bello as positive-law rules for the conduct of nations in war.
The law of armed conflict in international law remains one of the important arenas for the efforts to restrain war first defined in the just war tradition. In moral thought, largely as the result of work by the theologian Paul Ramsey (1913–1988) and the political philosopher Michael Walzer (b. 1935) and public debate occasioned by the U.S. Catholic bishops' 1983 pastoral The Challenge of Peace, just war thinking has reemerged in American and some European debates over the use of armed force, informing not only the religious and philosophical spheres but also public policy discussions and professional military education. Just war is studied in all the service academies and the war colleges and by military lawyers, and it is a common topic in academic and policy-oriented conferences and workshops on military issues.
Both historically and in recent debates just war tradition has responded to developments in the science and technology of the use of force. In the Middle Ages this involved efforts to eliminate the use of weapons that were deemed too harmful or destructive. Specifically, there was an effort to ban crossbows and bows and arrows, which could penetrate armor and kill, whereas the normal weapons of knights—swords, maces, and lances—were likely to injure but not kill armored opponents. Siege weapons capable of causing heavy and indiscriminate damage when used against fortified places were also the target of a ban.
These themes were carried forward into efforts to restrict or eliminate certain weapons or uses of weapons in positive international law. The first Hague Conference (1899) sought to ban exploding bullets for being too lethal and tending to inflict especially cruel wounds. That conference sought to ban asphyxiating gases, though this did not become positive law until the 1925 Geneva Protocol on gas warfare. Various efforts, beginning from the first Hague Conference, have been made to prohibit bombardment of unfortified population centers from the land, sea, and air. Since World War II international conventions have been adopted prohibiting the use of chemical and biological weapons as "weapons of mass destruction," and the nuclear proliferation treaty has sought to restrict possession of nuclear weapons as a way to limit the likelihood of their use. A 1980 United Nations Convention prohibits or restricts the use of certain conventional weapons "deemed to be excessively injurious or to have indiscriminate effects." The 1997 Ottawa Convention, responding to technologies that have made antipersonnel mines cheap, difficult to detect, and ubiquitous, formally prohibits their production, stockpiling, transfer, and use.
These are all examples from positive international law, a major modern carrier of the just war tradition. In the moral debate some have argued that the entire technology of contemporary warfare—not only weapons of mass destruction, including nuclear weapons, but also conventional weapons because of their ability to produce widespread death and destruction—is disproportionately and often indiscriminately harmful. This position, often called "modern-war pacifism" (including nuclear pacifism as one of its forms) holds that the technology of modern warfare is so destructive that the moral requirements of the jus in bello, avoidance of direct harm to noncombatants and of disproportionate destruction, cannot be met, and so there can be no just resort to force.
Opponents of this position, including Ramsey, Walzer, and James Turner Johnson (b. 1938), distinguish between the availability of highly destructive weaponry and the decision about how to fight: The latter is a moral decision, and it implies moral control over whatever means are available. In the debates over nuclear weapons during the early 1980s this difference of judgment about the technology of warfare led to two sharply different policy conclusions. Nuclear pacifists argued against nuclear weapons as inherently immoral and against the development of targeting technologies intended to make them more accurate and thus more discriminating. Others argued that development of such capabilities was a moral imperative both because it could reduce direct harm to noncombatants and because it opened the door to the development of lower-yield warheads, including conventional explosives, that could perform the same strategic and tactical functions as high-yield nuclear and thermonuclear warheads.
Questions of Technological Superiority
The policy decision at that time was to continue developing more accurate targeting technologies and delivery systems. Since then this line of development has matured progressively to produce a "revolution in military affairs" characterized by laser- and satellite-guided bombs and missiles, stealth technology that allows airplanes to get close enough to their targets to enable direct guidance of weaponry onto a target, drone airplanes and satellite imaging to identify and target enemy armed forces without collateral damage to non-combatants, and increasingly sophisticated means of gathering enemy intelligence to lower the levels of force needed for combat.
These developments first became general knowledge with publicity over the "smart bombs" of the 1991 Persian Gulf War. The use of such technology also marked the bombing of Serbia in the conflict over Kosovo (1999), and it was both ubiquitous and decisive in the conflicts in Afghanistan (2001) and Iraq (2003), where in the latter the technological superiority of the U.S. and British forces made possible a campaign that used far lower numbers of troops than previously would have been necessary, destroyed the Iraqi army while coalition forces suffered only a small number of casualties, and allowed bombs and missiles to destroy major Iraqi government targets with unprecedentedly low levels of collateral damage.
All this is morally significant from the standpoint of the just war tradition, for even in an age of weapons of massive destructive power such technology allows armed force to be used in a way that honors the just war requirements of noncombatant immunity and as low a level of destruction as possible. At the same time, from the perspective of the technologically inferior, the use of superior technology may appear to represent a refusal to accept an equal playing field in which courage and loyalty to opposing causes have a fair chance to compete with each other. What is to be made of this objection?
The latter argument cannot be used to justify means of fighting that disregard moral and legal restraints. In the moral terms of the just war tradition as well as the legal terms of the law of armed conflict, technologically superior and inferior adversaries are equally bound by the same rules. Technological inferiority is no excuse, for example, for terrorist actions against civilians or the Fedayeen Saddam's use of noncombatants as human shields in the 2003 Iraq war, both of which were clear violations of the moral concept of noncombatant immunity and the legal restrictions laid down in international law. In a conflict involving technologically asymmetrical adversaries each force is restricted, both morally and legally, to means that do not violate noncombatant immunity and do not involve prohibited weapons, such as weapons of mass destruction.
Technological asymmetry is not a new problem ushered in by precision-guided munitions. In earlier ages technological superiority was conferred by the use of Greek fire, firearms, rifled handguns and artillery, repeating rifles, the use of railroads for military transport, semaphore signaling systems and later the telegraph and radio, and the development of armored fighting vehicles. A technologically inferior armed force faces an enormous practical problem: how to match or overcome an enemy that is technologically superior. However, this is a practical problem, not a moral one. The idea of a "level playing field" means that both adversaries must play by the same rules; it does not mean that within the framework of those rules neither side may use means that it alone possesses.
The possession of superior technology, it may be argued, imposes a special moral responsibility to use that technology in ways that honor the jus in bello restraints. The moral rule of double effect has long been used to determine when collateral harm to noncombatants is morally allowed; by this rule such harm is allowed only when it is the indirect, formally unintended result of an attack on a legitimate military target that cannot be attacked except with such collateral harm. Thus, when an enemy places artillery next to a school or deploys troops with rifles to fire from the windows of a hospital, the artillery and the troops can be attacked despite the harm to the school and hospital and the noncombatant persons who may be inside.
However, Michael Walzer (1977) has argued that the rule of double effect also should be understood to impose a proportionality criterion; therefore, a projected attack against an otherwise legitimate target should not go forward if the collateral harm to noncombatants is judged to be disproportionate to the ends to be gained from the attack. In such cases, an alternative weapon or another means of neutralizing the target should be used or the target should be bypassed. This reasoning seems to have been employed in the targeting decisions made by U.S. forces in the 2003 Iraq conflict, in which the choice of weapons systems, the angle of attack, the time of day, fuse timing, and other factors were employed to avoid or reduce collateral damage. The possession of superior technology thus imposes an added moral burden: to use that technology to avoid harm that would be allowed in its absence.
This means that from a moral standpoint based on the just war tradition the question of the technology of warfare does not stand alone. It is also necessary to consider whether overall planning and policy, strategy, rules of engagement, means of command and control, tactics, and military training allow the use of the available technology in ways consonant with the aims of discrimination and proportionality. Not only does the U.S. military in the early twenty-first century have a virtual monopoly on the technology of the "revolution in military affairs," it is the only national military that has made operational all these elements in the channel of decision that leads toward conducting military actions within the framework required by the jus in bello. Arguably, the ability to conduct war more closely in accordance with just war requirements implies the moral obligation to do so. For example, carpet bombing of a mixed combatant-noncombatant area to destroy a legitimate target cannot be the moral option if precision guidance technology allows that target to be destroyed without harming noncombatants.
The question is what this implies for societies that lack such technology: Do they have the obligation to develop it, or may they not fight wars anymore? On just war reasoning, they have the moral obligation to use whatever means they have in the most moral way possible; they do not, for example, have the moral right to target civilians directly or use weapons of mass destruction, which are both indiscriminate and disproportionate. Beyond this they are obliged to try to develop more discriminate and proportionate means of fighting within the capabilities available to them and taking into account their other responsibilities. If they cannot fight according to the minimum standards of noncombatant immunity and avoidance of weapons mala in se, by just war reasoning they should not fight. However, the question whether to engage in armed conflict with a technologically superior adversary is not one of morality but one of political prudence.
The moral obligation to develop more discriminating and proportionate means of fighting extends also to technologically advanced militaries. During the Vietnam War Paul Ramsey (1968) argued for the use of incapacitating gases as morally preferable to the use of weapons such as napalm and even bullets because those gases could incapacitate soldiers without killing them or producing lasting harm. The United States Defense Advanced Research Products Administration has been encouraging research and development in nonlethal weapons technologies. Just war reasoning tends to support the development and use of such weapons in principle, though any particular weapon, even if nonlethal, still would have to be judged by the standards of the jus in bello.
In summary, just war tradition places the use of armed force in a moral framework in which some technologies are good and others are bad. The criterion is whether a specific technology makes it possible to use military force, when justified and used on public authority for the common good, in ways that honor the principles of noncombatant immunity and minimal overall destructiveness.
JAMES TURNER JOHNSON
Best, Geoffrey. (1980). Humanity in Warfare. New York: Columbia University Press. A historical study of the development of international laws on war, peace, and neutrality from the eighteenth through the twentieth centuries.
Elshtain, Jean Bethke. (2003). Just War against Terror. New York: Basic Books. An argument for the justification of the war on terror from a just war standpoint.
Johnson, James Turner. (1981). Just War Tradition and the Restraint of War. Princeton, NJ, and Guildford, Surrey, UK: Princeton University Press. A historical and thematic study of the just war tradition and its relation to the conduct of war from the Middle Ages through the twentieth century.
National Conference of Catholic Bishops. (1983). The Challenge of Peace: God's Promise and Our Response. Washington, DC: United States Catholic Conference. A landmark pastoral letter examining the Catholic tradition on war and peace in the context of the Reagan-era debate over nuclear weapons.
Ramsey, Paul. (1961). War and the Christian Conscience. Durham, NC: Duke University Press. A landmark study drawing Christian just war theory from the idea of love of neighbor and applying this theory to nuclear war.
Ramsey, Paul. (1968). The Just War: Force and Political Responsibility. New York: Charles Scribner's Sons. A collection of essays on political ethics, the idea of just war, and moral conduct applied to nuclear war and insurgency.
Russell, Frederick H. (1975). The Just War in the Middle Ages. Cambridge, UK, and New York: Cambridge University Press. A thorough and detailed historical study of the development of the just war idea from the twelfth-century canonists through Thomas Aquinas and his circle in the late thirteenth century.
Walzer, Michael. (1977). Just and Unjust Wars. New York: Basic Books. A reconstruction of the just war idea on the basis of philosophical analysis with historical illustrations, aimed at recapturing this idea for political and moral theory.
"Just War." Encyclopedia of Science, Technology, and Ethics. . Encyclopedia.com. (September 10, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/just-war
"Just War." Encyclopedia of Science, Technology, and Ethics. . Retrieved September 10, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/just-war