Post: Justification for ‘Holy War’

Those who advocate killing others in the context of a ‘Holy War’ often seek justification for their acts in religious texts.

 In the light of the recent rise of extreme groups such as IS (Islamic State), I have looked into some of these texts myself.   The following forms Chapter Three of  Abraham’s Children: Jew Christian Muslim, Commonality and Conflict.

Throughout the history of humankind there have been wars, despite all the horrors that follow in their wake. As a consequence of these horrors, whether individual death and suffering, destruction of wholesale communities, or widespread ecological damage, war has never been embarked upon lightly. Apart from being assured of reasonable success, rulers needed to have good reason or a just cause, for taking their people into battle. In other words, when is it justifiable to take up arms against an enemy? Furthermore, once engaged in battle, what are the ethics of war? What weapons should be used and how? How should property, prisoners, non-combatants and particularly women and children be treated?

In response to these questions there has developed in all traditions a ‘Just War Theory’. The criteria for a ‘Just War’ are usually divided into two; those concerning the right to go to war in the first place (jus ad bellum) and those concerning right conduct in war (jus in bello). Today there are calls for a third category dealing with post-war ethics covering such things as reparations and reconstruction. When a war is waged in the name of religion it might be termed a ‘holy war’, which could be seen as a contradiction in terms. However, history offers numerous examples of ‘holy wars’ and all three of the Abrahamic Faiths have developed their own doctrines regarding waging war in the name of ‘God’.


The earliest mention within Judaism regarding war is found in Deuteronomy 20 of the Hebrew Scriptures (Old Testament for Christians). The text does not lay down the criteria for going into war but advises on who should, or should not, go to war. For example, those who have no stomach for war should be excluded. Those have just built a new house, planted a vineyard or taken a new wife and not yet enjoyed any of their fruits are also exempt.

When the medieval philosopher and scholar Moses Maimonides wrote his ‘The laws of kings and their wars’ in the 12th century, he also specified that those who devote their lives to God should be exempt. Here he was speaking about the tribe of Levi who had responsibility for teaching and preaching. Deuteronomy 20, verse 10 also states that a besieged city should always be given an offer of peace in return for an agreed tribute, but should the offer be declined (verse 13) then ‘you shall put all its males to the sword, but the women and little ones, the cattle and everything else in the city, all its spoil, you shall take as bounty for yourselves; and you shall enjoy the spoil of your enemies, which the Lord your God has given you.’ At various times in their history both Christians and Muslims followed some of these same guidelines, particularly those concerning captives.

The Hebrew Scriptures are also quite clear that during hostilities no trees that bear fruit should be cut down (verse 19). Maimonides, in his commentary on the Midrash, also stipulated that a besieged city should never be completely surrounded, but that a gap should be left open for those who wished to escape. While there is nothing in the Hebrew Scriptures that specifically relates to the justification for going into war in the first place, Jewish scholars have taken the attitude that since there are so many directives in the Bible concerning right conduct in war, then the sad reality of war is a given. There is a clear distinction however between obligatory wars (milhemet mitzvah) and discretionary wars (milkhemet reshut).

An example of an obligatory war would be Joshua’s conquest of the Promised Land and many of the laws laid down in Deuteronomy are set within the context of his war against the seven nations of the Canaanites, namely the Hittites, Girgashites, Amorites, Canaanites, Perizzites, Hivites and Jebusites. Since Joshua was following the commandment of God to fight the Canaanites, this is thought to be an obligatory war and therefore sufficient justification for taking up arms against the Canaanites on the grounds of their ‘immorality’ and the need to eradicate the pagan nations before they could ‘contaminate’ the Israelites. As he was following God’s commandment this would also be termed a ‘holy war’.

It is generally recognised by Jewish scholars that Joshua’s wars of extermination are of historical interest only since the seven nations referred to no longer exist. Indeed, as early as the 2nd century the respected Rabbi Joshua ben Hananiah, stated that these seven nations were no longer identifiable. Even though these seven ‘pagan’ nations no longer exist, there is a minority of Jews among the settler communities of Israel today who believe that God’s commandment in Deuteronomy is binding on Jews for all time. They therefore believe that it is their divine obligation to reclaim the Land of Israel exclusively for the Jews as a prelude to the messianic age. Consequently they see themselves in a ‘holy war’ with the Palestinians, who are today’s equivalent of the ancient ‘seven nations’ and should therefore be ejected from the land of Israel. Although this is an extreme minority view it nevertheless poses an obstacle to peace in the Holy Land.


The 5th century philosopher and theologian, St Augustine of Hippo, formulated the first specifically Christian response to the problem of war. Augustine was the Bishop of Hippo (in modern Algeria) at a time when the Western Roman Empire, of which Algeria was a part, was being invaded by Germanic tribes from the North. The imperial city of Rome was then under threat and it was in this context that he wrote his seminal work The City of God in which he suggested that with the fall of Rome the imperial city would be replaced by a heavenly city of God. In this ‘heavenly city of God’ people should strive to uphold Christian values, one of which concerned the morality or otherwise of a faithful Christian taking up arms.

His conclusions, which became the foundation for the ‘just war theory’, are contained in The City of God and they have influenced Western attitudes towards war ever since. Augustine stressed that ideally Christians should be philosophically pacifist. However, he claimed that wars were a fact of life and there were circumstances when it was necessary to take up arms, particularly in defence of oneself, of others or one’s nation. Furthermore, he stated that war should only be embarked upon in self-defence, with the aim of restoring peace and also with the approval of a legitimate authority. Providing these conditions were fulfilled the Christian soldier would not be violating the commandment ‘Thou shalt not kill’.

In the 13th century another Christian philosopher and theologian, St Thomas Aquinas, reinforced Augustine’s teaching in his work Summa Theologica. Aquinas further stated that war should never be waged for expansionist reasons or for the gain of wealth and power.

The Crusades

With the onset of the medieval crusades ‘holy war’ as distinct from a ‘just war’ was legalised by the Church. While many of the basic rules of war remained the same, the essential difference was that a ‘holy war’ is fought in the name of religion or God. The medieval crusades were initially called by the Pope in response to an appeal from the Byzantine Emperor in Constantinople for military help against the Seljuk Turks who were making inroads into Byzantine territory.

In November 1095 CE, at the Council of Clermont, Pope Urban II called on the people of Europe to take up arms against the Turks. At the time Western Europe was politically unstable and his own position as Pope was also insecure. A call to arms, in the name of Christ, provided an opportunity to unite the warring factions of Europe against a common foe and in the process better secure his own position as Pope.

Several chroniclers recorded the Pope’s speech at Clermont and consequently there are variations in the text. However, they all record that the primary call to arms was not just to help the Byzantines, but to go much further and liberate the holy city of Jerusalem from the infidel Muslim. The following quotations are all taken from A Source Book for Medieval History, (New York: Scribners, 1905).

According to Fulcher of Chartres, Pope Urban proclaimed that:

      ‘the Turks and Arabs have attacked and conquered the territory of Romania (the Greek empire)…they have killed and captured many, and have destroyed the churches and devastated the empire. …I, or rather the Lord, beseech you…to persuade all people of whatever rank, foot-soldiers and knights, poor and rich, to carry aid promptly to those Christians and to destroy that vile race from the lands of our friends…Moreover, Christ commands it.’

It is thought that Robert the Monk, even though writing some 25 years after 1095 CE, was probably present at Clermont. He described the Muslims as:

      ‘an accursed race, a race utterly alienated from God, [that has] invaded the lands of those Christians and has depopulated them by the sword, pillage and fire…They circumcise the Christians, and the blood of the circumcision they either spread upon the altars or pour into the vases of the baptismal font’.

Robert also stressed that:

God has conferred upon you above all nations great glory in arms. Accordingly undertake this journey for the remission of your sins, with the assurance of the imperishable glory of the kingdom of heaven…all who were present cried out, “It is the will of God! It is the will of God!”.’

Clearly this is emotive language, emphasising the defilement and devastation of churches, holy places, and particularly Jerusalem. The graphic description of the cruel treatment of Christians by Muslims was probably exaggerated, aiming to incite anger and calls for vengeance. A call to arms in the name of God, with the promise of remission of sins for all and a place in heaven for those who may lose their lives, resulted in thousands, of all ages and from all levels of society across Europe, responding to the call of God to wage a ‘holy war’ and embark upon the long journey to Jerusalem.

For just over two centuries Western armies, made up of crusaders, adventurers and pilgrims, travelled from Europe to the Levant. During this time many thousands suffered on all sides, but particularly Jews living in towns and villages along the rivers Rhine and Danube became innocent targets of the crusading zeal. In March 2000 CE Pope John Paul II, while not explicitly mentioning the crusades, apologised for 2000 years of violence and persecution committed by the Church.


Historically Islam is the last of the three Abraham Faiths and has inherited aspects of both Judaism and Christianity. In terms of a ‘holy war’ we can detect the guidelines of Deuteronomy, Augustine and Aquinas in the Islamic texts that relate to war. Of all the three Faiths Islam has, within the Qur’an and the Hadith, probably the most detailed criteria for a just or ‘holy war’.

In popular terms an Islamic ‘holy war’ is usually referred to as a Jihad but this is a misunderstanding of the term. The word Jihad in Arabic literally means ‘struggle’ or ‘striving’ and Muslims understand it in two ways. The first and most important, the ‘greater Jihad’, refers to the daily struggle within the life of the individual who tries to live a Godly life. It is an on-going struggle within the self to overcome anything that hinders spiritual growth. The second, the ‘lesser Jihad’ refers to the outer struggle which could include physical or military action, but only under certain circumstances. Reference to Jihad appears in 30 verses of the Qur’an, six of which were revealed to Muhammad during his early period in Mecca, with 24 verses after 632 CE when he was in Medina, a time when the Muslims were in open conflict with the Quraish of Mecca. (see Chapter Two) According to a Hadith quoted by Joel Hayward in his book Islam and War, Muhammad made it clear that the inner, personal struggle is the more important of the two types of Jihad. Having returned from a battle, the Hadith states that Muhammad told his followers: ‘You have come back from the smaller jihad to the greater jihad’. When asked the meaning of the greater jihad, he replied: ‘the striving of Allah’s servant against his desires’.

While Muhammad was known for his preaching of peace and tolerance among the tribes, one particular text in the Qur’an, Surah 9:5, known as the verse of the sword, appears to promote almost universal violence against non-Muslims: ‘fight and slay the pagans wherever ye find them, seize them, beleaguer them, and lie in wait for them in every stratagem’ (of war).  Interestingly the New Testament also contains a controversial ‘sword’ verse. In Matthew 10:34 Jesus says ‘I came not to bring peace, but to bring a sword’.

Both traditions would claim that these verses are not justification for violence but need to be read in the wider context. Hayward states that if the Islamic verse is put into its correct context, it offers quite a different interpretation. The verse relates to the early period in Islamic history soon after the Muslims had agreed a peace treaty with the Meccans. Under the terms of the treaty, Mecca was recognised as a holy city and all pagan practices were completely abolished. Two years after the treaty was agreed it was broken and this was sufficient cause for Muhammad to give a stern warning to the idolaters. He offered an amnesty of four months to allow all pagans time to leave the city, failing which force would be applied. The text also urges Muslims to be merciful and offer sanctuary to any believers who ask for it.

The importance of this text is that it is directed against apostates; those who had previously accepted Islam under the treaty but had broken it and returned to paganism. As mentioned earlier, in Chapter Three, Islam takes a much harder line with its own people than with those of another Faith. We see the same phenomenon within Christianity with its treatment of so-called heretics, particularly during the European Reformation in the 16th century. Also, in the 15th century, the Spanish Inquisition was established by the monarchs Ferdinand and Isabella with the aim of rooting out Jews who had converted to Christianity (conversos) but were suspected as having secretly reverted to Judaism.

Justification for Jihad

The Qur’an gives the following as justifiable reasons for embarking upon a military Jihad: self-defence, strengthening Islam, protecting freedom of worship, protecting Muslims against oppression, punishing those who break an oath and putting right a wrong. Most of these reasons are open to wide interpretation and many Muslims today would interpret that of ‘Protecting Muslims against oppression’ as clear justification for military Jihad. Equally the Qur’an is clear as to what is not justifiable, for example: forced conversion to Islam, to conquer or colonise another nation, to take territory for economic gain, to settle disputes or to demonstrate power.

Rules of Jihad

There are many rules laid down in the Qur’an relating to conduct in a war situation. For example, non-combatants, especially women, children and old people should not be killed; women should not be raped; wounded enemy soldiers should receive the same treatment as Muslim soldiers; property should not be damaged nor should wells be poisoned. The last point about the poisoning of wells can be compared to the Jewish prohibition against cutting down vine trees. In both cases there is an acknowledgement that the effects of war are not limited to casualties within the immediate war zone but have repercussions across whole regions and for generations later. The use of biological and chemical warfare today would be a modern example. The key point in Islam regarding warfare is that war is only permissible in self-defence. This could be defence of territory, the right to worship and the protection of Muslims against oppression. Furthermore, military action should never be embarked upon without first having exhausted all efforts to come to a peaceful solution.


Since warfare has been part of the human condition from ancient times, all three Abrahamic Faiths, starting with Judaism, have tried to reconcile the Scriptural injunction ‘not to kill’, with the necessity of taking up arms. However, there had to be justification for going to war in the first place (the just war/jus ad bellum). There was also a need to lay down ethical guidelines for those engaged in war (jus in bello). Furthermore, in the light of modern warfare, it is recognised that a third category, dealing with post war ethics, is called for. While in the Judaeo-Christian tradition the concept of a ‘holy war’ is probably implicit in the Hebrew Scriptures, it became explicit and clearly articulated at the time of the 11th century Crusades with the call to liberate Jerusalem from the Muslims. In Islam the ‘holy war’ is the lesser of the two Jihads, or struggles that are incumbent upon all Muslims.

The common feature across all traditions is that any war should only be embarked upon in self-defence. The difficulty is defining the term ‘self-defence’. Part of Joshua’s justification for going to war was to ‘defend’ the Israelites from the threat of the pagan worship of the Canaanites. It is difficult to see how the Crusades were in any way ‘defensive’ wars. Although they were aimed at liberating Jerusalem, that city had been under Islamic rule for over four hundred years. Even though Islam has the most detailed guidelines for both going into war and ethical conduct during war, there still remains opportunity for a very wide interpretation.