International law on the use of force is deeply rooted in what is one of the dominant philosophical perspectives on the morality of war – Just War theory. The doctrine has its origins in Christianity, as it was first put together by Christian thinkers in the late Middle Ages, and its initial purpose was to reconcile two opposing approaches of Christianity; namely absolute pacifism and crusadism.


Just War theory espouses a strong stance against war, which can nevertheless be overridden in certain cases. It distinguishes between three main problems: the conditions under which is it permissible to go to war (jus ad bellum), the requirements of just fighting (jus in bello), and the responsibilities of war-making states in the aftermath of war (jus post bellum). International law draws extensively on Just War theory – the UN Charter regulates the resort to war and the Geneva Conventions govern its conduct.

With international Islamic terrorism on the rise and a considerable number of contemporary armed conflicts occurring within or between countries that are predominantly Muslim, the question concerning the stance of Islam on the morality of war is becoming increasingly pressing. Is the Islamic understanding of what it means to fight a just war in harmony with the rules of international law, or does it diverge from them? The rich scholarship on the Islamic ethics of war reveals that there are more points of convergence than we may have expected. The writings of traditional scholars, such as the members of the Iraqi and Hanafi schools of Islamic thought, reveal that some of the main precepts of Just War theory, such as just cause, right intention, right authority, and the principle of discrimination between civilians and combatants, have their counterparts in the Islamic ethics of war. Moreover, the way these principles are understood in the two traditions is very similar. For example, war is considered just if it is pursued in self-defence or in defence of those who have been unjustly attacked. The traditional belief that war of conquest aiming to expand the Islamic faith is permissible and even praiseworthy has been rejected by the majority of contemporary Islamic scholars.

Interestingly enough, the two traditions are also similar in terms of their weaknesses. Both the theory of Just War and the Islamic ethics of war argue that it is impermissible to target innocents, but their understanding of innocence may be flawed. Considered innocent are those persons who are deemed not to pose a military threat. This formulation gives military personnel on the ground a lot of freedom to decide whom they can legitimately target. Instead, some thinkers suggest that innocence in the context of war is intimately linked to the idea of moral liability to attack – only those who have through their acts rendered themselves liable to attack, for example by harming others, can be subjects of war.

Another shared weakness relates to the way the two traditions interpret the meaning of the doctrine of double effect. They take it to mean that death and injury inflicted upon a civilian population are permissible, as long as they are foreseen but unintended. However, this is too simplistic an  understanding of double effect. Contemporary just war theorists emphasise that additional conditions need to be met: the unintended evil effects have to be absolutely necessary for the attainment of some good effects of considerable importance, and the military personnel on the ground have to make a special effort to minimise the evil effect even if this means putting themselves at greater risk.

Despite the many similarities between Just War theory and the Islamic ethics of war, there is a danger that the dialogue between the two doctrines will be stalled in the future. The Islamic tradition heavily relies on the practice of looking for hidden meanings of Koranic words and reasoning by analogy. As a result, a plethora of different interpretations of Islam and its position on the justice of war have emerged. Furthermore, there is no formal codification of rules on war within the Islamic tradition and experts warn that there is an increasingly fragmented sense of authority within Islam, which is leading to a ‘direct competition for control of the symbolic discourse of Islam’. This has allowed interpretations put forward by Islamic extremists to gain significant influence. In their 1998 Declaration Concerning Armed Struggle against Jews and Crusaders, the members of the World Islamic Front, most notably Osama bin Laden, claimed that it is permissible to attack civilians and military targets without discrimination. They tried to justify this argument on the basis of reciprocity – since Western states had allegedly acted in this way in Muslim countries, it would be permissible to respond in a similar fashion.

Some scholars rejoice in the myriad of existing interpretations of Islam’s stance on war – they see it as a sign that the discourse on Islam is being democratised. However, this can also entail certain dangers as the case of Islamic extremism shows. Leading international actors, such as the UN, have deemed it more prudent to promote a single dominant interpretation of Islam – one that presents the Islamic faith as religion of peace. The UN has done so by passing a number of resolutions in which it condemns militant interpretations of Islam. The question remains whether we should strive to democratize the debate on Islam and its position on war by allowing for multiple opinions and interpretations, or stifle discursive diversity for the sake of security and peace.