Religious war

During classical antiquity, the Greco-Roman world had a pantheon with particular attributes and interest areas. Ares personified war. While he received occasional sacrifice from armies going to war, there was only a very limited "cult of Ares".[28] In Sparta, however, each company of youths sacrificed to Enyalios before engaging in ritual fighting at the Phoebaeum.[29]

Hans M. Barstad (2008) claimed that this ancient Greek attitude to war and religion differed from that of ancient Israel and Judah: 'Quite unlike what we find with the Greeks, holy war permeated ancient Israelite society.'[30] Moreover, ever since the pioneering study of Manfred Weippert, "»Heiliger Krieg« in Israel und Assyrien" (1972), scholars have been comparing the holy war concept in the (monotheistic) Hebrew Bible with other (polytheistic) ancient Near Eastern war traditions, and found 'many [striking] similarities in phraseology and ideology'.[30]

The St. Bartholomew's Day massacre of French Protestants, 1572

According to historian Edward Peters, before the 11th century, Christians had not developed a concept of holy war (bellum sacrum), whereby fighting itself might be considered a penitential and spiritually meritorious act.[31][32] During the ninth and tenth centuries, multiple invasions occurred which led some regions to make their own armies to defend themselves and this slowly lead to the emergence of the Crusades, the concept of "holy war", and terminology such as "enemies of God" in the 11th century.[31][32] In early Christianity, St. Augustine's concept of just war (bellum iustum) was widely accepted, but warfare was not regarded as a virtuous activity[31][33] and expressions of concern for the salvation of those who killed enemies in battle, regardless of the cause for which they fought, was common.[31]

During the era of the Crusades, some of the Crusaders who fought in the name of God were recognized as the Milites Christi, the soldiers or the knights of Christ.[34] The Crusades were a series of military campaigns against the Muslim Conquests that were waged from the end of the 11th century through the 13th century. Originally, the goal of the Crusaders was the recapture of Jerusalem and the Holy Land from the Muslims, and the provision of support to the besieged Christian Byzantine Empire which was waging a war against Muslim Seljuq expansion into Asia Minor and Europe proper. Later, Crusades were launched against other targets, either for religious reasons, such as the Albigensian Crusade, the Northern Crusades, or because of political conflicts, such as the Aragonese Crusade. In 1095, at the Council of Clermont, Pope Urban II raised the level of the war from a bellum iustum (a "just war"), to a bellum sacrum (a "holy war").[35]

In the Hindu texts, dharma-yuddha refers to a war that is fought while following several rules that make the war fair.[36] In other words, just conduct within a war (jus in bello) is important in Vedic and epic literature such as the Mahabharata and the Ramayana.[37] However, according to Torkel Berkke, the Mahabharata does not provide a clear discussion on who has the authority to initiate a war (jus ad bellum), nor on what makes a war just (bellum justum).[37]

The Muslim conquests were a military expansion on an unprecedented scale, beginning in the lifetime of Muhammad and spanning the centuries, down to the Ottoman wars in Europe. Until the 13th century, the Muslim conquests were those of a more or less coherent empire, the Caliphate, but after the Mongol invasions, expansion continued on all fronts (other than Iberia which was lost in the Reconquista) for another half millennium until the final collapse of the Mughal Empire in the east and the Ottoman Empire in the west with the onset of the modern period.

There were also a number of periods of infighting among Muslims; these are known by the term Fitna and mostly concern the early period of Islam, from the 7th to 11th centuries, i.e. before the collapse of the Caliphate and the emergence of the various later Islamic empires.

Fulani jihad states of Africa, c. 1830

While technically, the millennium of Muslim conquests could be classified as "religious war", the applicability of the term has been questioned. The reason is that the very notion of a "religious war" as opposed to a "secular war" is the result of the Western concept of the separation of Church and State. No such division has ever existed in the Islamic world, and consequently there cannot be a real division between wars that are "religious" from such that are "non-religious". Islam does not have any normative tradition of pacifism, and warfare has been integral part of Islamic history both for the defense and the spread of the faith since the time of Muhammad. This was formalised in the juristic definition of war in Islam, which continues to hold normative power in contemporary Islam, inextricably linking political and religious justification of war.[38] This normative concept is known as Jihad, an Arabic word with the meaning "to strive; to struggle" (viz. "in the way of God"), which includes the aspect of struggle "by the sword".[39]

The first forms of military jihad occurred after the migration (hijra) of Muhammad and his small group of followers to Medina from Mecca and the conversion of several inhabitants of the city to Islam. The first revelation concerning the struggle against the Meccans was Quran 22:39-40:[40]

To those against whom war is made, permission is given (to fight), because they are wronged;- and verily, Allah is most powerful for their aid. (They are) those who have been expelled from their homes in defiance of right,- (for no cause) except that they say, "our Lord is Allah". Did not Allah check one set of people by means of another, there would surely have been pulled down monasteries, churches, synagogues, and mosques, in which the name of Allah is commemorated in abundant measure. Allah will certainly aid those who aid his (cause);- for verily Allah is full of Strength, Exalted in Might, (able to enforce His Will).

— Quran 22:39-40 - Abdullah Yusuf Ali Translation

This happened many times throughout history, beginning with Muhammad's battles against the polytheist Arabs including the Battle of Badr (624), and battles in Uhud (625), Khandaq (627), Mecca (630) and Hunayn (630).

Midianite women, children and livestock taken captive by Israelite soldiers after all Midianite men had been killed and their towns burnt. Watercolour by James Tissot (c. 1900) illustrating the War against the Midianites as narrated in Numbers 31.

Reuven Firestone (2012) stated 'that holy war is a common theme in the Hebrew Bible. Divinely legitimized through the authority of biblical scripture and its interpretation, holy war became a historical reality for the Jews of antiquity. Among at least some of the Jewish groups of the late Second Temple period until the middle of the second century, C.E., holy war was an operative institution. That is, Jews engaged in what is defined here as holy war.'[41] He mentioned the Maccabean Revolt (167–160 BCE), the First Jewish–Roman War (66–73 CE) and the Bar Kokhba revolt (132–136 CE) as three examples of a "holy war" or "Commanded War" (Hebrew: מלחמת מצווה Milkhemet Mitzvah) in the eyes of Rabbinic Judaism at the time.[41] He asserted that this concept may have re-emerged in modern times within some factions of the Zionist movement, particularly Revisionist Zionism.[42]

In 2016, however, Firestone made a distinction between what he regarded as the Hebrew Bible's concept and the 'Western' concept of holy war: ""Holy war" is a Western concept referring to war that is fought for religion, against adherents of other religions, often in order to promote religion through conversion, and with no specific geographic limitation. This concept does not occur in the Hebrew Bible, whose wars are not fought for religion or in order to promote it but, rather, in order to preserve religion and a religiously unique people in relation to a specific and limited geography."[43]

Several scholars regard war narratives in the Hebrew Bible, such as the war against the Midianites in Numbers 31, to be a holy war, with Niditch (1995) asserting the presence of a 'priestly ideology of war in Numbers 31'.[44] Hamilton (2005) argued that the two major concerns of Number 31 are the idea that war is a defiling activity, but Israelite soldiers need to be ritually pure, so they may only fight wars for a holy cause, and are required to cleanse themselves afterwards to restore their ritual purity.[45] The Israelite campaign against Midian was blessed by the Israelite god Yahweh, and could therefore be considered a holy war.[45] Olson (2012), who believed the war narrative to be a fictional story with a theological purpose, noted that the Israelite soldiers' actions in Numbers 31 closely followed the holy war regulations set out in Deuteronomy 20:14, although Moses' commandment to also kill the captive male children and non-virgin women was a marked departure from these regulations.[46] He concluded: "Many aspects of this holy war text may be troublesome to a contemporary reader. But understood within the symbolic world of the ancient writers of Numbers, the story of the war against the Midianites is a kind of dress rehearsal that builds confidence and hope in anticipation of the actual conquest of Canaan that lay ahead."[46]

Dawn (2016) stated: "From the earliest days of Israel's existence as a people, holy war was a sacred institution, undertaken as a cultic act of a religious community".[47]

The Saxon Wars (772–804) of Frankish king Charlemagne against the Saxons under Widukind were described by Jim Bradbury (2004) as 'in essence a frontier struggle and a religious war against pagans – devil-worshippers according to Einhard.'[55] He noted that Charlemagne ordered the destruction of the Irminsul, an object sacred to the Saxons.[55] Per Ullidtz (2010) stated that previous Frankish–Saxon conflicts spanning almost a century 'had been mostly a border war', 'but under Charles it changed character': because of 'Charles' idea of unity, of a king over all German tribes, and of universal Christianity in all of his kingdom, it changed into a mission from heaven.'[56] Similarly, a successful Carolingian campaign against the Pannonian Avars in the 790s led to their forced conversion to Christianity.[55] The earlier Merovingian conquests of Thuringia, Allemannia and Bavaria had also resulted in their Christianisation by 555, although the Frisians resisted with similar determinacy as the Saxons during the Frisian–Frankish wars (7th and 8th century), with both tribes killing several Christian missionaries in defence of their Germanic paganism, to the horror of Christian hagiographers.[56]

The Crusades are a prime example of wars whose religious elements have been extensively debated for centuries, with some groups of people in some periods emphasising, restoring or overstating the religious aspects, and other groups of people in some periods denying, nuancing or downplaying the religious aspects of the Crusades in favour of other factors. Winkler Prins/Encarta (2002) concluded: "The traditional explanation for the Crusades (a religious enthusiasm that found an outlet in a Holy War) has also retained its value in modern historical scholarship, keeping in mind the fact that it has been pointed out that a complex set of socio-economic and political factors allowed this enthusiasm to manifest itself."[57]

The Crusades against Muslim expansion in the 11th century were recognized as a "holy war" or a bellum sacrum by later writers in the 17th century. The early modern wars against the Ottoman Empire were seen as a seamless continuation of this conflict by contemporaries.[58]

A battle of the Reconquista from the Cantigas de Santa Maria

Jim Bradbury (2004) noted that the belligerents in the Reconquista were not all equally motivated by religion, and that a distinction should be made between 'secular rulers' on the one hand, and on the other hand Christian military orders which came from elsewhere (including the three main orders of Knights Templar, Knights Hospitaller and Teutonic Knights), or were established inside Iberia (such as those of Santiago, Alcántara and Calatrava).[59] '[The Knights] were more committed to religious war than some of their secular counterparts, were opposed to treating with Muslims and carried out raids and even atrocities, such as decapitating Muslim prisoners.'[59]

The Battle of Las Navas de Tolosa, known in Arab history as the Battle of Al-Uqab (معركة العقاب), was fought on 16 July 1212 and it was an important turning point in both the Reconquista and the medieval history of Spain.[60] The forces of King Alfonso VIII of Castile were joined by the armies of his Christian rivals, Sancho VII of Navarre, Pedro II of Aragon and Afonso II of Portugal in battle[61] against the Berber Muslim Almohad conquerors of the southern half of the Iberian Peninsula.

The relative importance of the various factors that caused the Hussite Wars (1419–1434) is debated. Kokkonen & Sundell (2017) claimed that the death of king Wenceslaus IV of Bohemia on 19 August 1419 is the event that sparked the Hussite rebellion against his nominal heir Sigismund (then king of Germany, Hungary and Croatia), making it essentially a war of succession.[62] Nolan (2006) named religion as one of several significant causes, summarising the Hussites' motives as 'doctrinal as well as "nationalistic" and constitutional', and providing a series of issues that led to war: the trial and execution of Jan Hus (1415) 'provoked the conflict', the Defenestration of Prague (30 July 1419) 'began the conflict', while 'fighting began after King Wenceslaus died, shortly after the defenestration' (that is, after 19 August 1419).[63] Nolan described the wars' goals and character as follows: 'The main aim of the Hussites was to prevent the hated Sigismund mounting the throne of Bohemia, but fighting between Bohemian Hussites and Catholics spread into Moravia. (...) cross-class support gave the Hussite Wars a tripartite and even "national" character unusual for the age, and a religious and social unity of purpose, faith, and hate'.[64] Winkler Prins/Encarta (2002) described the Hussites as a 'movement which developed from a religious denomination to a nationalist faction, opposed to German and Papal influence; in the bloody Hussite Wars (1419–1438), they managed to resist.' It didn't mention the succession of Wenceslaus by Sigismund,[65] but noted elsewhere that it was Sigismund's policy of Catholic Church unity which prompted him to urge Antipope John XXIII to convene the Council of Constance in 1414, which ultimately condemned Jan Hus.[66]

Buddhism was formally introduced into Japan by missionaries from the kingdom of Baekje in 552. Adherents of the native Shinto religion resisted the spread of Buddhism, and several military conflicts broke out,[67] starting with the Soga–Mononobe conflict (552–587) between the pro-Shinto Mononobe clan (and Nakatomi clan) and the pro-Buddhist Soga clan. Although the political power each of the clans could wield over the royal family was also an important factor, and was arguably a strategic reason for the Soga to adopt and promote Buddhism as a means to increase their authority, the religious beliefs from both doctrines, as well as religious explanations from events that happened after the arrival of Buddhism, were also causes of the conflict that escalated to war.[68] Whereas the Soga argued that Buddhism was a better religion because it had come from China and Korea, whose civilisations were widely regarded as superior and to be emulated in Yamato (the central kingdom of Japan), the Mononobe and Nakatomi maintained that there should be continuity of tradition and that worshipping the native gods (kami) was in the best interest of the Japanese.[68] Unable to reach a decision, Emperor Kinmei (r. 539–571) maintained Shinto as the royal religion, but allowed the Soga to erect a temple for the statue of Buddha.[68] Afterwards, an epidemic broke out, which Shintoists attributed to the anger of the native gods to the intrusion of Buddhism; in reaction, some burnt down the Buddhist temple and threw the Buddha statue into a canal.[68] However, the epidemic worsened, which Buddhists in turn interpreted as the anger of Buddha to the sacrilege committed against his temple and statue.[68] Both during the 585 and 587 wars of succession, the opposing camps were drawn along the Shinto–Buddhist divide, and the Soga clan's victory resulted in the imposition of Buddhism as the Yamato court religion under the regency of Prince Shotoku.[68]

There have been several religious wars in the Toltec Empire of Mesoamerica (c. 980–1110) between devotees of Tezcatlipoca and followers of Quetzalcoatl; the latter lost and were driven to flee to the Yucatán Peninsula.[69]

The term "religious war" was used to describe, controversially at the time, what are now known as the European wars of religion, and especially the then-ongoing Seven Years' War, from at least the mid 18th century.[70] The Encyclopædia Britannica maintains that "[the] wars of religion of this period [were] fought mainly for confessional security and political gain".[71]

In 16th-century France, there was a series of wars between Roman Catholics and Protestants (Huguenots primarily), known as the French Wars of Religion. In the first half of the 17th century, the German states, Scandinavia (Sweden, primarily) and Poland were beset by religious warfare during the Thirty Years War. Roman Catholicism and Protestantism figured on the opposing sides of this conflict, though Catholic France took the side of the Protestants, but it did so for purely political reasons.

In the late 20th century, a number of revisionist historians such as William M. Lamont regarded the English Civil War (1642–1651) as a religious war, with John Morrill (1993) stating: 'The English Civil War was not the first European revolution: it was the last of the Wars of Religion.'[72] This view has been criticised by various pre-, post- and anti-revisionist historians.[72] Glen Burgess (1998) examined political propaganda written by the Parliamentarian politicians and clerics at the time, noting that many were or may have been motivated by their Puritan religious beliefs to support the war against the 'Catholic' king Charles I of England, but tried to express and legitimise their opposition and rebellion in terms of a legal revolt against a monarch who had violated crucial constitutional principles and thus had to be overthrown.[73] They even warned their Parliamentarian allies to not make overt use of religious arguments in making their case for war against the king.[73] However, in some cases it may be argued that they hid their pro-Anglican and anti-Catholic motives behind legal parlance, for example by emphasising that the Church of England was the legally established religion: 'Seen in this light, the defenses of Parliament's war, with their apparent legal-constitutional thrust, are not at all ways of saying that the struggle was not religious. On the contrary, they are ways of saying that it was.'[74] Burgess concluded: '[T]he Civil War left behind it just the sort of evidence that we could reasonably expect a war of religion to leave.'[75]

Horn of Africa circa 1540 during the Ethiopian–Adal War, at the peak of al-Ghazi's expansion.

  Adal Sultanate

  Ethiopian Empire (Abyssinian/Habesha Kingdom)

The Ethiopian–Adal War (1529–1543) was a military conflict between the Abyssinians and the Adal Sultanate. The Imam Ahmad ibn Ibrahim al-Ghazi came close to extinguishing the ancient realm of Abyssinia, and forcibly converting all of its surviving subjects to Islam. The intervention of the European Cristóvão da Gama attempted to help to prevent this outcome, but he was killed by al-Ghazi. However, both polities exhausted their resources and manpower in this conflict, allowing the northward migration of the Oromo into their present homelands to the north and west of Addis Ababa.[76] Many historians trace the origins of hostility between Somalia and Ethiopia to this war.[77] Some historians also argue that this conflict proved, through their use on both sides, the value of firearms such as the matchlock musket, cannons, and the arquebus over traditional weapons.[78]

The Greek War of Independence (1821–1829) has sometimes been considered a religious war between Christians and Muslims, especially in its early phase. The Greek Declaration of Independence (issued on 15 January 1822) legitimised the armed rebellion against the Ottoman Empire in a mix of religious and nationalist terms: 'The war we are waging against the Turks, far from being founded in demagoguery, seditiousness or the selfish interests of any one part of the Greek nation, is a national and holy war (...). It is from these principles of natural rights and desiring to assimilate ourselves with our European Christian brethren, that we have embarked upon our war against the Turks.'[79] Scottish writer Felicia Skene remarked in 1877: 'The Greek war of independence has never been called a religious war, and yet it had a better claim to that appellation than many a conflict which has been so named by the chroniclers of the past. It is a significant fact that the standard of revolt was raised by no mere patriot, but by Germanus, the aged Archbishop of Patras, who came forward, strong in his spiritual dignity (...) to be the first champion in the cause of Hellenic liberty.'[80] Ian Morris (1994) stated that 'the uprising in 1821 was mainly a religious war', but that philhellene Western volunteers joined the war for quite different reasons, namely to 'regenerate' Greece and thereby Europe, motivated by Romantic ideas about European history and civilisation, and Orientalist views of Ottoman culture.[81] The Filiki Eteria, the main organisation driving the rebellion, was split between two groups: one advocated the restoration of the Byzantine Empire on religious grounds, and to encourage all Christians within Ottoman territory to join the Greek revolutionaries; the other advocated the Megali Idea, a large Greek nation-state based on shared language rather than religion.[81] Both of these grand objectives failed, but a smaller version of the latter goal was accepted by most members of the Eteria by 1823, and this goal was generally compatible with the motives of philhellenes who travelled to Greece to enter the war in 1821–23.[81]

A fatally wounded Israeli school boy in a Hamas attack, 2011

The Israeli–Palestinian conflict can primarily be viewed as an ethnic conflict between two parties where one party is most often portrayed as a singular ethno-religious group which only consists of the Jewish majority and ignores non-Jewish minority Israeli citizens who support the existence of a Zionist state to varying degrees, especially the Druze and the Circassians who, for example, volunteer to serve in the IDF, participate in combat and are represented in the Israeli parliament in higher numbers and greater percentages than Israeli Jews are[82][83] as well as Israeli Arabs, Samaritans,[84] various other Christians, and Negev Bedouin;[85] the other party is sometimes presented as an ethnic group which is multi-religious (although most numerously consisting of Muslims, then Christians, then other religious groups up to and including Samaritans and even Jews). Yet despite the multi-religious composition of both of the parties in the conflict, elements on both sides often view it as a religious war between Jews and Muslims. In 1929, religious tensions between Muslim and Jewish Palestinians over Jews praying at the Wailing Wall led to the 1929 Palestine riots[86] including the Hebron and Safed ethnic cleansings of Jews.

In 1947, the UN's decision to partition the Mandate of Palestine, led to the creation of the state of Israel and Jordan, which annexed the West Bank portion of the mandate, since then, the region has been plagued with conflict. The 1948 Palestinian exodus also known as the Nakba (Arabic: النكبة),[87] occurred when approximately 711,000 to 726,000 Palestinian Arabs fled or were expelled from their homes, during the 1948 Arab–Israeli War and the Civil War that preceded it.[88] The exact number of refugees is a matter of dispute, though the number of Palestine refugees and their unsettled descendants registered with UNRWA is more than 4.3 million.[89][90] The causes remain the subject of fundamental disagreement between Palestinians and Israelis. Both Jews and Palestinians make ethnic and historical claims to the land, and Jews make religious claims as well.[91]

The All India Muslim League (AIML) was formed in Dhaka in 1906 by Muslims who were suspicious of the Hindu-majority Indian National Congress. They complained that Muslim members did not have the same rights as Hindu members. A number of different scenarios were proposed at various times. This was fuelled by the British policy of "Divide and Rule", which they tried to bring upon every political situation. Among the first to make the demand for a separate state was the writer/philosopher Allama Iqbal, who, in his presidential address to the 1930 convention of the Muslim League said that a separate nation for Muslims was essential in an otherwise Hindu-dominated subcontinent.

After the dissolution of the British Raj in 1947, British India was partitioned into two new sovereign states—the Dominion of India and the Dominion of Pakistan. In the resulting Indo-Pakistani War of 1947–1948, up to 12.5 million people were displaced, with estimates of loss of life varying from several hundred thousand to a million.[92] India emerged as a secular nation with a Hindu majority, while Pakistan was established as an Islamic republic with Muslim majority population.[93][94]

Inter-ethnic conflict in Nigeria has generally had a religious element. Riots against Igbo in 1953 and in the 1960s in the north were said to have been sparked by religious conflict. The riots against Igbo in the north in 1966 were said to have been inspired by radio reports of mistreatment of Muslims in the south.[95] A military coup d'état led by lower and middle-ranking officers, some of them Igbo, overthrew the NPC-NCNC dominated government. Prime Minister Balewa along with other northern and western government officials were assassinated during the coup. The coup was considered an Igbo plot to overthrow the northern dominated government. A counter-coup was launched by mostly northern troops. Between June and July there was a mass exodus of Ibo from the north and west. Over 1.3 million Ibo fled the neighboring regions in order to escape persecution as anti-Ibo riots increased. The aftermath of the anti-Ibo riots led many to believe that security could only be gained by separating from the North.[96]

In the 1980s, serious outbreaks between Christians and Muslims occurred in Kafanchan in southern Kaduna State in a border area between the two religions.

The 2010 Jos riots saw clashes between Muslim herders against Christian farmers near the volatile city of Jos, resulting in hundreds of casualties.[97] Officials estimated that 500 people were massacred in night-time raids by rampaging Muslim gangs.[98]

During the rule of the Catholic Ngo Dinh Diem in South Vietnam, the discrimination against the majority Buddhist population generated the growth of Buddhist institutions as they sought to participate in national politics and gain better treatment. The Buddhist Uprising of 1966 was a period of civil and military unrest in South Vietnam, largely focused in the I Corps area in the north of the country in central Vietnam.[99]

In a country where the Buddhist majority was estimated to be between 70 and 90 percent,[100][101][102][103][104] Diem ruled with a strong religious bias. As a member of the Catholic Vietnamese minority, he pursued pro-Catholic policies that antagonized many Buddhists.

The Dungan revolt (1862–1877) and Panthay Rebellion (1856–1873) by the Hui were also set off by racial antagonism and class warfare, rather than the mistaken assumption that it was all due to Islam that the rebellions broke out.[105] During the Dungan revolt fighting broke out between Uyghurs and Hui.

In 1936, after Sheng Shicai expelled 20,000 Kazakhs from Xinjiang to Qinghai, the Hui led by General Ma Bufang massacred their fellow Muslims, the Kazakhs, until there were only 135 of them left.[106][107]

Tensions with Uyghurs and Hui arose because Qing and Republican Chinese authorities used Hui troops and officials to dominate the Uyghurs and crush Uyghur revolts.[108] Xinjiang's Hui population increased by over 520 percent between 1940 and 1982, an average annual growth rate of 4.4 percent, while the Uyghur population only grew by 1.7 percent. This dramatic increase in the Hui population led inevitably to significant tensions between the Hui and Uyghur Muslim populations. Some old Uyghurs in Kashgar remember that the Hui army at the Battle of Kashgar (1934) massacred 2,000 to 8,000 Uyghurs, which caused tension as more Hui moved into Kashgar from other parts of China.[109] Some Hui criticize Uyghur separatism, and generally do not want to get involved in conflicts in other countries over Islam for fear of being perceived as radical.[110] Hui and Uyghur live apart from each other, praying separately and attending different mosques.[111]

War-damaged buildings in Beirut

There is no consensus among scholars on what triggered the Lebanese Civil War (1975–1990). However, the militarization of the Palestinian refugee population, along with the arrival of the PLO guerrilla forces, sparked an arms race for the different Lebanese political factions. However, the conflict played out along three religious lines: Sunni Muslim, Christian Lebanese and Shiite Muslim, Druze are considered among Shiite Muslims.

It has been argued that the antecedents of the war can be traced back to the conflicts and political compromises reached after the end of Lebanon's administration by the Ottoman Empire. The Cold War had a powerful disintegrative effect on Lebanon, which was closely linked to the polarization that preceded the 1958 political crisis. During the 1948 Arab–Israeli War, an exodus of Palestinian refugees, who fled the fighting or were expelled from their homes, arrived in Lebanon. Palestinians came to play a very important role in future Lebanese civil conflicts, and the establishment of Israel radically changed the local environment in which Lebanon found itself.

Lebanon was promised independence, which was achieved on 22 November 1943. Free French troops, who had invaded Lebanon in 1941 to rid Beirut of the Vichy French forces, left the country in 1946. The Christians assumed power over the country and its economy. A confessional Parliament was created in which Muslims and Christians were given quotas of seats. As well, the president was to be a Christian, the prime minister a Sunni Muslim and the speaker of Parliament a Shia Muslim.

In March 1991, Parliament passed an amnesty law that pardoned all political crimes prior to its enactment. The amnesty was not extended to crimes perpetrated against foreign diplomats or certain crimes referred by the cabinet to the Higher Judicial Council. In May 1991, the militias (with the important exception of Hezbollah) were dissolved, and the Lebanese Armed Forces began slowly to rebuild themselves as Lebanon's only major non-sectarian institution.

Some violence still occurred. In late December 1991 a car bomb (estimated to carry 220 pounds of TNT) exploded in the Muslim neighborhood of Basta. At least 30 people were killed, and 120 wounded, including former Prime Minister Shafik Wazzan, who was riding in a bulletproof car.

In the case of the Iran–Iraq War (1980–1988), the new revolutionary government of the Islamic Republic of Iran generally described the conflict as a religious war,[112] and used the narrative of jihad to recruit, mobilise and motivate its troops.[112][113]^{: 9:24, 16:05} On the other hand, justifications from the Saddam Hussein-led Ba'athist Iraq were mostly framed in terms of a supposed Persian–Arab historical enmity, and Iraq-centred Arab nationalism (including support for Arab separatism in Khuzestan).[112] Some of the underlying motives of Saddam appear to have been controlling the Shatt al-Arab waterway and region (previously settled by the 1975 Algiers Agreement, which had ended Imperial Iranian support for the 1974–75 Kurdish rebellion against the Iraqi government[113]^: 3:27), obtaining access to the oil reserves in Khuzestan, and exploiting the instability of post-Revolution Iran, including the failed 1979 Khuzestan insurgency.[113]^: 3:06 Peyman Asadzade (2019) stated: 'Although the evidence suggests that religious motivations by no means contributed to Saddam's decision to launch the war, an overview of the Iranian leaders' speeches and martyrs' statements reveals that religion significantly motivated people to take part in the war. (...) The Iranian leadership painted the war as a battle between believers and unbelievers, Muslims and infidels, and the true and the false.'[112] Iran cited religious reasons to justify continuing combat operations, for example in the face of Saddam's offer of peace in mid-1982, rejected by Ayatollah Khomeini's declaration that the war would not end until Iran had defeated the Ba'athist regime and replaced it with an Islamic republic.[113]^: 8:16

While Ba'athist Iraq has sometimes been described as a 'secular dictatorship' before the war, and therefore in ideological conflict with the Shia Islamic 'theocracy' which seized control of Iran in 1979,[113]^: 3:40 Iraq also launched the so-called Tawakalna ala Allah ("Trust in God") Operations (April–July 1988) in the final stages of the war.[113]^: 16:05 Moreover, the Anfal campaign (1986–1989; in strict sense February–September 1988) was code-named after Al-Anfal, the eighth sura of the Qur'an which narrates the triumph of 313 followers of the new Muslim faith over almost 900 pagans at the Battle of Badr in the year 624.[114] "Al Anfal" literally means the spoils (of war) and was used to describe the military campaign of extermination and looting commanded by Ali Hassan al-Majid (also known as "Chemical Ali").[114] His orders informed jash (Kurdish collaborators with the Baathists, literally "donkey's foal" in Kurdish) units that taking cattle, sheep, goats, money, weapons and even women as spoils of war was halal (religiously permitted or legal).[114] Randal (1998, 2019) argued that 'Al Anfal' was 'a curious nod to Islam' by the Ba'athist government, because it had originally been known as a 'militantly secular regime'.[114] Some commentators have concluded that the code name was meant to serve as 'a religious justification' for the campaign against the Kurds.[115]

The Croatian War (1991–95) and the Bosnian War (1992–95) have been viewed as religious wars between the Orthodox, Catholic and Muslim populations of former Yugoslavia: respectively called "Serbs", "Croats" and "Bosniaks" (or "Bosnian Muslims").[116][117] Traditional religious symbols were used during the wars.[118] Notably, foreign Muslim volunteers came to Bosnia to wage jihad and were thus known as "Bosnian mujahideen". Although some news media and some scholars at the time and in the aftermath often described the conflicts as nationalist or ethnic in nature,[note 1] others such as the literary critic Christopher Hitchens (2007) have argued that they were religious wars[note 1] (Catholic versus Orthodox versus Islamic), and that terms such as "Serb" and "Croat" were employed as mere euphemisms to conceal the religious core of the armed conflicts, even though the term "Muslims" was frequently used.[119][note 2] Some scholars have stated that they "were not religious wars", but acknowledged that "religion played an important role in the wars" and "did often serve as the motivating and integrating factor for justifying military attacks".[note 1]

The Second Sudanese Civil War from 1983 to 2005 has been described as an ethnoreligious conflict where the Muslim central government's pursuits to impose sharia law on non-Muslim southerners led to violence, and eventually to the civil war. The war resulted in the independence of South Sudan six years after the war ended. Sudan is majority-Muslim and South Sudan is majority-Christian.[122][123][124][125]