Tragedies of war have received significant attention in Judaism and Christianity. War was common in the biblical world. In the pre-Christian era, Israel knew few periods of peace, and that reality continued into the Christian era. Throughout its 2,000-year history, the Bible has been used to justify, rationalize, restrain, and inform war and the conduct of warfare. In various times and by various means, biblical ethicists have upheld and departed from consensual standards, debating and denying the existence of such standards. Both ecclesiastical and secular leaders have appealed to biblical teachings for personal and national guidance and support of war.

Central to a theological understanding of war is a belief in the broken nature of humanity. Humanity and every aspect of personal and corporate life are marred by original sin. Sinful nature corrupts international relations as well as interpersonal relations. War is ultimately a reflection of the consequences of sin. Wars are fought on battlefields but are waged first in human hearts. The question regarding participation in war is whether war in all cases is avoidable. Pacifists answer yes, just-war proponents answer no. The death, destruction, horrors, and personal and property losses of war are real. To think ethically about issues of war is to struggle with the problem of evil. While there has not been unanimity of thought regarding biblical understandings of participation in war, all acknowledge its tragic character.

Biblical ethical responses to war range from absolute rejection to full participation in war with proclamations of divine authority and blessing. The spectrum has ranged from the pacifist words of the American folk hymn “Gonna lay down my sword and shield down by the riverside, ain’t gonna study war no more” to the Middle Ages’ crusader cry, “God wills it!”

Lexical Terms in the Bible.

Terminology for war occurs frequently in the Bible. In the Jewish scriptures (Christian Old Testament), the Hebrew term most frequently translated “war” is milḥamâ, also translated as “fight” and “battle” (e.g., Gen 14:2). It occurs more than 300 times. A cognate word to milḥamâ is the verb lāḥam, “fight,” “do battle.” It is often rendered “make war” (e.g., Deut 20:19; Josh 10:5; Judg 11:4). Two other Hebrew words are ṣāb_ā, “service in war,” also translated “war” (e.g. Num 1:3, 20), and qerāb_ (“hostile approach,” “fight”), likewise translated as “war” (e.g., Ps 55:21 [Heb 55:22]; 68:30 [68:31]; 144:1). In the Septuagint, the Greek noun polemos normally used translates the Hebrew milḥamâ and is the most common term used for “war.” The intertestamental period saw no new terms arise.

In the New Testament, the Greek noun polemos is usually rendered as “war” and occurs 16 times. The word occurs first in classical Greek from the era of Homer onward. In the New Testament, the term applies both literally and figuratively to armed conflicts (e.g., Matt 24:6; Heb 11:34; Rev 11:7; 12:17; 13:7; 19:19) and to interpersonal quarrels or strife (e.g., Jas 4:1). The cognate verb polemeō, “make war” or “fight,” occurring 7 times, also refers both to intense wars (e.g., Rev 2:16; 17:14; 19:11) and to interpersonal conflicts (Jas 4:2). The verb strateuō, “to serve as a soldier,” and the related terms strateia (“battle,” “warfare”), strateuma (“army,” “soldier”), and stratiōtēs (“soldier”) are used a total of 45 times, both literally and figuratively. For example, in 2 Corinthians 10:3; James 4:1; and 1 Peter 2:11 strateuomai, “do military service, serve in the army” is translated as “war.” In the latter two verses the term is applied figuratively to personal internal struggles. In Romans 7:23 the verb antistrateuomai, “be at war against,” refers to waging battle between the law of God and the power of sin. In 2 Corinthians 10:4 and 1 Timothy 1:18 the New Revised Standard Version translates the Greek noun strateía, “military campaign,” a term used only figuratively in the New Testament, as “warfare” and “fight,” respectively.

War in the Hebrew Bible/Old Testament.

Warfare was common in the ancient Near Eastern world and practiced virtually universally during the biblical period. War was often prevalent in Near Eastern cosmologies for both creation and control of the earth and the heavens by the gods. In the Babylonian Enuma Elish, order is attained by the god Marduk as a result of his conquest of the deities of chaos. Since the gods maintained cosmological order through warfare, so too warfare was acceptable, if not mandatory, for maintaining order in human affairs, and religious connotations were often ascribed to it. The human ruler became the earthly counterpart of the divine warrior-king. Often, the chief god of a state or people was a god of war. Warfare was thus tied closely to religious beliefs and practices. Warfare in the ancient Near East was consistently perceived from a theological or religious perspective where the state and gods were integrally connected. Religious ritual and awareness permeated warfare. Practices included consultation of the gods and sacrifices to them before battle, prayer and solicitation of divine assistance before battle, the presence of adviser-priests on the battlefield, and services of thanksgiving for victory following battle. The Israelites reflected many of the ideas of the surrounding environment but with distinctive interpretation and new application of the theology and practice of war resulting from sole allegiance to Yahweh.

War and murder.

Considerations of biblical ethical perspectives on war must consider the biblical commandment not to murder (Deut 5:15; 20:13) and ask how it relates to war. The prohibition is specifically against murder, not killing. In biblical Hebrew seven different words are used in relation to killing. In this instance, the Hebrew verb rasah refers to premeditated and intentional killing of an individual and not killing in war or capital punishment (Gen 9:6; Exod 21:12). Although the verb has often been translated as “kill,” the Hebrew more specifically refers to murder.

The Bible does not equate killing in war with murder. In later Christian thought, the just-war tradition makes a distinction between murder and killing in warfare that occurs within the parameters of recognized ethical, legal, and religious standards. While some killing that occurs in war is murder and a war crime atrocity, deaths that occur as a result of lawful and legitimate military operations are not considered murder.

War and the Israelites.

Much warfare is recorded in the Hebrew scriptures. The first reference to war is of a coalition of four Mesopotamian kings who invaded five cities of the plain in the Dead Sea region and were pursued by Abraham and his forces (Gen 14:1–16). War occurred throughout Israelite history from the exodus from Egypt through the period of the conquest of Canaan to the rise of the united monarchy (Saul, David, and Solomon) and throughout the history of the divided kingdoms of Israel (922–722 B.C.E.) and Judah (922–586 B.C.E.). The northern state of Israel was defeated by the Assyrians in 722 B.C.E. (2 Kgs 17:1–6) and never reemerged as an independent state. The southern kingdom of Judah was defeated by the armies of the Neo-Babylonian Empire 587–586 B.C.E. and ceased to exist as an independent state (2 Kgs 25; Jer 52).

The biblical term most often associated with holy war in the Hebrew Bible is herem, a difficult term to translate; when used in the context of war, it means “ban” in the sense that something or someone is under a ban for destruction. It also refers to plundered items and people who are captured during the course of holy war. It is first used in Numbers 21:2–3 and is commonly referred to either as “holy war” or more accurately “Yahweh war.” The use of the designation Yahweh war by biblical scholars as opposed to holy war conveys the religious character of Israel’s warfare without implying that the conduct of war had moral or religious worth. It emphasizes the act of war rather than the acts in war.

A common epithet for God in the Hebrew text is “Lord of hosts” (lit. “Lord of armies”), an expression used more than 200 times. According to Exodus 15:3: “The LORD is a warrior; the LORD is his name” (see also Ps 24:8). These verses and many others show that association of God with war was central to Israel and Hebrew theology in which God participated in Israel’s experience of war. War in ancient Israel was undertaken as a cultic act, the conscious ritual act of a religious community that was in covenant relationship with Yahweh.

Yahweh war is one of the most troubling ethical and theological issues in the Hebrew Bible. The Israelites are portrayed (e.g. Deut 20; Josh 6:17–21) as being used by Yahweh as instruments of divine judgment with warfare as the context in which judgment is mediated. Several times Yahweh commands the Israelites to have no mercy on the enemy armies, population, and animals in battle (Num 31:17; Deut 20:16–18; Josh 11:20; 1 Sam 15:18). In Deuteronomy 7:2 the phrases “utterly destroy” and “show them no mercy” carry the connotation of devoted destruction that is a meticulous, intense, and intentional annihilation of the enemy comparable to genocide. The book of Joshua used the language of contemporary warfare rhetoric (Josh 10:40–42; 11:16–23), but exaggerations—e.g. “all”—were accepted cultural and literary devices indicating victory but not necessarily absolute destruction, as evident from other statements in the biblical record indicating that absolute destruction was not accomplished (Judg 1).

The concept of peace (šālôm) in the Hebrew text is a broad one. The word šālôm can imply peace as distinct from warfare but it has the fundamental notion of “wholeness, integrity.” Peace may exist simply in the absence of warfare, but it is incomplete. True peace presupposes the healthy society where there is both justice and righteousness. The prophet Jeremiah observed that people may say “peace, peace,” when in reality there is no peace (Jer 6:14). The well-known vision of swords being beaten into ploughshares and spears into pruning hooks (Isa 2:4; Mic 4:3) is shared by two eighth-century B.C.E. prophets but should not be interpreted as declarations of pacifism. The prophets’ vision of peace was balanced by contemporary experiences of war and the prophets affirmed that God acted in a judgmental role in warfare.

War in the Intertestamental Period (ca. 425 B.C.E.–ca. 35 C.E.).

Warfare during the years between the writing of the last book of the Old Testament and the first book of the New Testament was dominated by the Persians and Greeks and, subsequently, the Greeks and Romans. Persian control lasted until 330 B.C.E. and the rise of Alexander the Great (356–323 B.C.E). Alexander’s domination of the Israelites gave way to the Egyptian Ptolemaic and Syrian Seleucid dynasties (323–166 B.C.E.), resulting in their control of Judea and Palestine. These were followed by 100 years of Jewish independence under the Maccabees and Hasmonean dynasty from 166–63 B.C.E. The Maccabean revolt occurred during the era of Jewish independence, as recorded in 1 and 2 Maccabees. Viewed by Jews as a religious war that was coupled with strong political motivations, this revolt led to the establishment of the independent Jewish kingdom that combined the offices of high priest and king. It also resulted in the rise of several distinct groups in Judaism, such as those who lived in the region of the Dead Sea (250 B.C.E.–70 C.E.) and who generated the scrolls discovered there in 1947. These scrolls and fragments contain one document popularly known as “The War Scroll” (1QM, first century B.C.E.). It is probably based on a Roman military manual, in that it has detailed instructions on fighting and tells of an apocalyptic conflict between the Sons of Light and the Sons of Darkness—that is, between the members of the Dead Sea community who are viewed as being on God’s side and all others, including the established priesthood at Jerusalem, the Romans, and the remainder of the world. The apocalyptic battle depicted in it reflects military organization and tactics similar to those known from contemporary Roman practices.

In 63 B.C.E., Pompey of Rome conquered Palestine, putting all of Judea under Roman control, bringing in an era that would last through the years of the life of Jesus of Nazareth, the writing of the New Testament, and the beginning of Christianity.

War in the New Testament.

The world of the New Testament, including Jerusalem and Judea as well as much of larger area of Mediterranean and missionary journeys of the apostle Paul, was controlled by the Roman Empire. While the celebrated Pax Romana was present, the military and political presence in Judea was that of an occupying force. Although there is no historical record of conflict in the New Testament, Jesus speaks of “wars and rumor of wars” (Matt 24:6) as one of the signs of the last days. He accepts war as part of the conditions of the present age but also teaches that his followers are to have an ethic that supersedes others and sets them apart from nonbelievers. Additionally Jesus used a military illustration of the calculation and commitment required by a king contemplating war as an example of the commitment required of one of Jesus’s disciples (Luke 14:31–33). In Luke 19:41–44, Jesus wept over the city of Jerusalem and prophesied its destruction—something that occurred in 70 C.E. Jesus spoke of himself figuratively stating: “Do not think that I have come to bring peace to the earth; I have not come to bring peace, but a sword” (Matt 10:34). In Luke 22:36, Jesus told his disciples “the one who has no sword must sell his cloak and buy one” and yet on the night of his betrayal and arrest, he told a disciple to put away his sword and warned that “all who take the sword will perish by the sword” (Matt 26:52; see also Luke 22:38, 48–51). Whatever broader application Jesus’s words may have, they do not deny governments all uses of the sword, nor does the New Testament teach individuals not to use violence. The use of force in resisting and punishing violence is entrusted to governments, not individuals.

While under arrest in Acts, Paul experienced the barracks of Roman soldiers at Jerusalem and Caesarea (Acts 21:34, 37; 23:35). Additionally, while a prisoner in Rome, he likely became familiar to the members of the Praetorian Guard who guarded him (Phil 1:13).

Apart from apocalyptic imagery of war in Revelation (as well as the presentation of similar events in Jesus’s teachings in the gospels), the emphasis of the New Testament regarding war is not a topic of discussion per se, but consists of illustrations, metaphors, and other figures of speech pertaining to war. The apostles use war to illustrate spiritual struggles of individuals, divine protection, and Christian victory over sin and opposition (Rom 7:23; 8:37; 2 Cor 10:3, 5; Eph 6:10–17; 1 Tim 1:18; Heb 13:13; Jas 4:1; 1 Pet 1:5; 2:11). They also use war imagery in reference to the triumphs of Jesus Christ (2 Cor 2:14; Eph 2:16–17; Col 2:15).

The apocalyptic imagery of Revelation foresees an end of death and war and a new Jerusalem whose city gates will never be closed, indicating the threat of siege and war forever ended (Rev 21:25). The final defeat of Satan and sin is portrayed in the language and imagery of war with a final victory for righteousness and Jesus Christ in a battle known as the battle of Armageddon, ending the cosmic spiritual struggle of the ages (Rev 16:14–16; 17:14; 19:14; see also Dan 11:40–45; Joel 3:9–17; Zech 14:1–3 for passages often interpreted as pertaining to Armageddon).

Jewish–Roman Wars (66–ca. 135 C.E.).

The three Jewish-Roman wars of the last half of the first century C.E. through the first third of the second century strongly affected early Judaism and Christianity. The First Jewish-Roman War (66–73 C.E.) included an insurrection in Galilee, the destruction of Jerusalem and the Jewish Temple in 70, and the fall of Masada in 73. The Kitos War (115–117 C.E. also called the “Rebellion of the Exile” or the Second Jewish-Roman War) consisted of revolts by Jews in Cyrene, Cyprus, Mesopotamia, and the Roman province of Egypt. The third war, the Bar Kokhba revolt (132–135 C.E.), is sometimes called the Second War when the Kitos War is not counted. Led by a messianic and heroic figure known as Simon bar Kokhba, the revolt in Judea established an independent state that lasted for two years before being crushed by the Roman army. Importantly, this war helped differentiate Christianity and Judaism.

War in Early Christianity.

There is significant disagreement among historians regarding the position of the early church toward war and military service. Until recent decades, many historians argued that early Christianity was uniformly and unequivocally pacifist. This was the view of influential church historian Roland Bainton (1894–1984). Bainton argued that the history of Christianity regarding war was a three-step progression moving from pacifism to the just war to the crusade perspective. It was, according to him, a progressive fall from primitive purity. Others arguing for a thoroughly pacifist early church include C. John Cadoux (1883–1947) and, more recently, American Mennonite theologian John Howard Yoder (1927–1997). However, patristic research since the 1980s has significantly challenged the view of a predominantly pacifistic early church and shown that the evidence for either pacifism or the embracing of military service by early Christians is at best mixed. Christians in the first four centuries were far from unanimous in their attitudes to war.

In the first century there was a general avoidance of military service by Christians. However, the reason for this was not necessarily pacifism and an abhorrence of war. Rather, there was an abstaining from many social, commercial, and political activities in the expectation of the imminent Second Coming of Christ. It was not so much pacifism as it was an other-worldly expectation—the expectation of the coming of Christ’s kingdom rather than acceptance of Caesar’s already present earthly kingdom. It was not necessarily so much explicitly violence and war as it was the affairs of the world that were to be shunned by Christians due to eschatological expectations.

During the second and third centuries, there was a mixture of participation and pacifism. There was a plurality of views. There were also other social and religious reasons for not participating in the military. In an environment where Christians were frequently persecuted because of their faith and because they were seen as unsupportive of the Roman state, service would have been difficult for many of them. Some of the rejection of military service in the early church was not an embracing of pacifism, but a rejection of idolatrous practices within the Roman army. These practices included taking an oath to the emperor who was appointed as Pontifex Maximus and participation in a military system that included oaths to the standards of the legion and a religious system within the military. The discovery of the Feriale Duranum—a calendar of Roman army religious festivals for 226 C.E.—showed festivals for the imperial cult and the army that included sacrifices and other activities that would have been viewed as idolatrous by Christians.

The structure of the Roman military also would have made Christian worship within it difficult and thus Tertullian spoke against the military (On Idolatry 19.2). For soldiers in the Roman army who converted to Christianity it was unlikely that they were able to leave the army since enlistments were for 20 years. Christians in the army would have had to associate and worship when possible with other Christians in urban areas and forego worship when serving on the frontiers of the empire.

In spite of pagan religious practices in the Roman army, it contained some Christians, and in at least one legion, the Legio Fulminata (“Thundering Legion”), Christians may have been a majority. There is evidence that from 173 C.E. onward significant numbers of Christians were in the military despite occasional attempts to purge them.

There are clear statements by early Christian theologians against military service. Both Tertullian (ca. 160–225 C.E.), who argued against military service on the grounds of idolatry, and Origen (185–254 C.E.), who argued against it because killing is not the way of Christ, rejected Christian participation in the military. Other voices include Cyprian, Clement of Alexandria, and Hippolytus.

Contemporary patristic scholarship indicates that early Christian statements regarding war and military service were not a falling away or abandonment of apostolic purity. If indeed the first-century Christians avoided war and the military because of their eschatological expectations, then as those expectations changed with time, there arose the opportunity for pluralistic interpretations of the role of Christians in society, including war and the military. Both the view of pacifism and the acceptance of military service that led to the just-war tradition of the fourth century onward were positions that differed from first-century Christians who avoided the issues of military service and war because of expectations that their present world was to be short lived.

Christian Just-War Tradition.

The just-war tradition developed over centuries and has three important functions. First, it seeks to limit the outbreak and devastation of war. Second, it offers a common moral framework and language with which to discuss issues of war in the public arena. Third, it gives moral guidance to individuals in developing their conscience, responsibilities, and response.

Although heavily influenced by Christianity, proponents also drew from Roman law and Greek philosophy. Christian just-war thinking begins to emerge in the writings of Ambrose (ca. 330–397) and Augustine (354–430). From the writings of these thinkers there is an emphasis that Christians not remain aloof from affairs of the state and world as they await the eschaton. Both leaders discuss the moral criteria regarding whether and how to engage in the use of coercive force. Both also renounced the right to self-defense, although Augustine permits it for the soldier and for the soldier acting in defense of others. Both argue that Christian love requires defense and protection of innocent third parties.

The influence of Ambrose and especially Augustine dominated western philosophy and theology throughout the Middle Ages, and Augustine’s ideas regarding war were continued by Thomas Aquinas (1225–1274). Central to the idea is that justice and charity are not at odds. Justice is concerned with the right ordering of society for the sake of social peace. Since either a just peace or unjust peace is possible, there must be a striving for just peace, which may involve war. The just-war tradition has just peace as its goal since even tyrants can have peace.

Augustine’s discussion of war is a subset of his views on citizenship and his concern that Christians not abdicate civic responsibilities. Ethical principles governing whether or not to go to war (jus ad bellum) and how to proceed in the midst of war ( jus in bello) are derived from his writings. These principles, to which recently more guidelines for postconflict justice (jus post bellum) have been added, became standard categories of the tradition. Within the two categories of jus ad bellum and jus in bello there are seven principles for the just war. The first five apply as a nation is “on the way to war” ( jus ad bellum) and the final two apply to military forces “in the midst of war” ( jus in bello). They are just cause, right intention, last resort, formal declaration, limited objectives, proportionate means, and noncombatant immunity.

The definition, interpretation, and application of the principles are not agreed upon unanimously. Nor is there assurance that they will always receive strict adherence. However, the intent of them is not to promulgate war, but to contain it. They are principles of containment, not of conflagration.

There are four presuppositions of just-war tradition: some evil in the world is unavoidable; just-war tenets are ethically normative for all people; the just-war tradition is an attempt to bring war within the limits of justice so that if everyone were guided by its principles, many wars would be eliminated; the just-war position assumes that individuals do not have the right to use military force. Only governments have such a right. This last presupposition is important because it contends that the key issue is not whether an individual can fight in war, but whether a government has the right to engage in armed conflict and whether a citizen, irrespective of religious commitments, should participate as an agent of that government. An individual’s participation in any conflict under just-war thought is a matter of conscience.

The just-war tradition is not a monolithic perspective with unanimous assent to all of its aspects by advocates through the centuries. Rather, it is a consensual perspective that has undergone continuous refinement as new circumstances and fresh challenges have arisen. In recent decades there has been a resurgence of just-war thinking that includes a variety of perspectives in both secular and religious spheres; but not without criticism. Concerns about applicability of the framework to contemporary warfare also force proponents to answer new question. For example, does the tradition privilege the state over the individual? Does the tradition need complete replacement? What about the increasing trend to place children in harm’s way or to use child soldiers? What about the use of unmanned weapons systems or cyber conflict? Critics also contend that what counts as a “war” is far from clear-cut, and therefore applicability of the just-war tradition will always be open to question. Others argue that suffering and death of people in any war means that war can never be morally justified and that even if it could be justified, the criteria of the just-war tradition will not be respected.

Christianity and the Crusades.

Warfare in the West has not been synonymous or always complementary with the just-war tradition. The crusades, Spanish Inquisition, sixteenth-century wars of religion, and wars of colonial expansion are some of the many violent episodes that failed to uphold the values of the just-war tradition. In part, the just-war tradition responded in reaction to such brutal conflicts.

Aspects of the just-war tradition were present and debated during the crusades era. Although war was not new in Christian history, linking it with penance and spiritual vitality was unique and the idea emerged that a holy war (the term “crusade” was only used later), was acceptable and justifiable when it was understood as directly commanded by God and proclaimed by the papacy. When Pope Urban II preached the crusade, calling upon western Christians to aid Christians in the Byzantine East and recover Jerusalem from Islamic control, crowds reportedly responded with cries of “Deus lo volt!” (“God wills it!”). These words became a battle cry during the bloody crusade centuries—centuries during which Christians slaughtered Christians as well as non-Christians.

At the same time, there were also developments in political theory based upon differing interpretations of Augustine’s City of God regarding the proper roles of princes and popes in maintaining the political community. Eventually the right of the prince as the leader of secular society to make war for religious as well as political reasons won out and set a pattern that lasted until the conclusion of the Thirty Years War (1648).

Christian Pacifism.

Pacifism in Christian theology and practice also has a long history, with strands dating to the early Christian era based on interpretation of specific biblical texts such as Matthew 5:9, 38–42. The three most vocal advocates of pacifism in early Christianity were Tertullian (166–220), Origen (ca. 185–254), and Lactantius (ca. 240–320). Normally two strands of argumentation are presented in Christian pacifism—first, nonviolence always brings better results than war (pragmatic argument); second, war is incompatible with what it means to be a follower of Jesus (Christian witness argument).

Pragmatic argument strengths include recognition of a variety of effective methods of political action. Often, nonviolent means can be more effective than violence in promoting a group’s goals. Additionally, it is a reminder of the great cost of violence. Strengths of the witness argument are that it recognizes that a judgment about pacifism is most basically a theological judgment. It does not depend upon any judgment about whether nonviolence is an effective means to peace. Additionally, it takes with great seriousness the nature of the Christian spiritual life.

Pragmatic argument critics contend that it does not adequately recognize the depth and stubbornness of the human condition due to sin and gives moral preference to tyranny over war. Some argue also that the decentralized structure of international politics makes some occurrence of war likely in spite of efforts to prevent it. Finally, critics argue that the pragmatic argument dogmatically overstates the effectiveness of nonviolence.

Similarly, witness argument critics contend it also has weaknesses. It rests upon a minority interpretation of Christian love (agape). It denies Christian responsibility for attempts to prevent unjustifiable violence on others. Finally, critics argue that it completely separates the church and the world, the temporal and the spiritual. Critics of pacifism contend its principle shortcoming is that it misidentifies morality of the individual as justification for (or morality of) the behavior of the state.

Yet, pacifism recognizes diverse means for political action taking seriously the commitment to neighbor-love and the demands of Christian faith. It is sensitive to distortions of faith that come with an uncritical view of the state.

Historic Christian pacifism, in its sixteenth-century Anabaptist form, like its counterpart today, rejected the views of Roman Catholicism and Protestant reformers such as Martin Luther, John Calvin, and Ulrich Zwingli regarding Christian participation in the affairs of the state. While not all associated with the “radical Reformation” and Anabaptists were pacifists, most were, and the writings of Menno Simons (1496–1561) provided broad theological justification for Anabaptist beliefs to the present.

Not all Protestants shared the views of the magisterial Reformers like Luther and Calvin on military service and war, though most agreed with them. Many Protestant denominations and other groups including Roman Catholicism, Greek Orthodoxy, and Anglicanism also have strands of pacifism (especially concerning nuclear weapons). Because Protestant Reformers assumed natural law as the moral theological bedrock in their system, they maintained ethical continuity with Roman Catholic counterparts. The Reformation controversies were primarily theological, not ethical.

War and Roman Catholic Social Thought.

As with Protestantism, there is no unified thinking within Roman Catholicism regarding war, although there are definitive statements in the 1992 Catechism of the Church. Diversity of thought can be seen in the prominent documents The Challenge of Peace (1983) and The Harvest of Justice Is Sown in Peace (1993), published by the U.S. Catholic Bishops’ Conference. Both documents deviate from classical just-war thinking to the extent that they conflate the baseline assumptions of the pacifist and the just-war positions, beginning with a presumption against war and coercive force rather than a presumption against evil and injustice, which is the basic operating assumption of classical just-war thinking. Both documents received criticism for not declaring unambiguously that coercive force is not evil and that based on intention force takes on the moral character of those employing it. By contrast, the Catechism, following Augustine and Aquinas, cites moral and prudential guidelines for determining conditions for going to war and for conduct in war. But it also maintains that ultimately it is the responsibility of political officeholders and not the church to make policy decisions regarding a nation and war.

Multiple Issues of War.

Apart from absolute pacifism, regardless of where one stands on the spectrum of responses to problems of war, issues remain that one must consider from biblical, ethical, and historical perspectives. These range from individual to collective responses, from low-intensity conflict to use of weapons of mass destruction and all other potentials within the range of military operations, and many single issue topics, including the responsibility to protect noncombatants, humanitarian intervention, torture, targeting, terrorism, nonstate actors, war crimes and tribunals, unmanned weapons systems, rules of engagement, disagreements between international humanitarian law and the law of armed conflict, child soldiers, mercenaries, private contractors on the battlefield, human rights, environment, cyber conflict, and the role of the international community.


Thinking about war from a perspective of Christian ethics means wrestling with ideas and values that are upheld because they are greater than any individual, nation, or era. In the early-modern era, the contributions of Christian thinkers on war such as Francisco de Vitoria (ca. 1483–1546), Suarez (1548–1617), or Hugo Grotius (1583–1645) were influential in the development of law and international relations. Currently, contributions of ethicists with regard to war include, at the most basic level, an approach to international law grounded in universal “laws of humanity” (originally rooted in natural law theory), by which international relations might be governed, and concomitantly, clearly defined rules of international law for the conduct of war. Voices across the political spectrum have been central to the development of western ideas about ethics and war.




  • Charles, J. Daryl, and Timothy J. Demy. War, Peace, and Christianity: Questions and Answers from a Just-War Perspective. Wheaton, Ill.: Crossway, 2010.
  • Clouse, Robert G., ed. War: Four Christian Views. Downers Grove, Ill.: InterVarsity, 1981.
  • Cowles, C. S., Merrill, Eugene H., Daniel L. Gard, and Tremper Longman III. Show Them No Mercy: Four Views on God and Canaanite Genocide. Grand Rapids, Mich.: Zondervan, 2003.
  • Craigie, Peter C. The Problem of War in the Old Testament. Grand Rapids, Mich.: Eerdmans, 1978.
  • Helgeland, John. “Christians and the Roman Army, A.D. 173–337.” Church History 43:2 (1974): 149–163, 200.
  • Helgeland, John, Robert J. Daly, and J. Patout Burns, Christians and the Military: The Early Experience. Philadelphia: Fortress, 1985.
  • Holmes, Arthur F., ed. War and Christian Ethics: Classic and Contemporary Readings on the Morality of War. 2d ed. Grand Rapids, Mich.: Baker Academic, 2005.
  • Johnson, James Turner. Morality and Contemporary Warfare. New Haven, Conn.: Yale University Press, 1999.
  • Longman, Tremper, III, and Daniel G. Reid. God Is a Warrior. Grand Rapids, Mich.: Zondervan, 1995.
  • O’Donovan, Oliver. The Just War Revisited. Cambridge, U.K.: Cambridge University Press, 2003.
  • Rad, Gerhard von. Holy War in Ancient Israel. Translated and edited by Marva J. Dawn. Grand Rapids, Mich.: Eerdmans, 1991.
  • Yadin, Yigael. The Art of Warfare in Biblical Lands in the Light of Archeological Study. Translated by M. Pearlman. New York: McGraw-Hill, 1963.
  • Yoder, John Howard. Christian Attitudes to War, Peace, and Revolution. Edited by Theodore J. Koontz and Andy Alexis-Baker. Grand Rapids, Mich.: Brazos, 2009.

Timothy J. Demy