The use of high-tech weapons with higher lethality in today's military operations increases the sensitivity of the assessments and evaluations on just war. Although the just war theory is not a new concept, it has started to be pronounced again and more frequently. In a new sense, the criteria he uses in his re-statement are being used to justify military interventions in the name of democracy and human rights. Just war does not envisage offence. The simple distinction between offence and defence lies in the concept of self-defence. Today, self-defence is not only used for the purpose of punishment, which is a different application of the known definition (preventive self-defence) by the one in power, but also as pre-emptive self-defence. There is an ongoing debate among scholars regarding the practicality and relevance of categorising wars as justified or unjustified.

Just War

The Vietnam, Arab-Israeli, Gulf and Afghanistan Wars, which took place less than half a century after the Second World War, have brought about significant changes in the levels of warfare, modes of warfare, doctrine and principles used. During this period, battles of various sizes and scales have been observed, ranging from small and medium-scale conflicts to combined land, sea and air operations across the operational area. Changes in the structure and levels of modern warfare have brought new dimensions to the concepts of warfare and operations.

The planners and politicians of future wars will have to take into account the possibilities that technological developments will bring to the weapons and means of warfare on the one hand, and the general international political situation and the ever-changing structure of the battle environment on the other.

In parallel with these developments, new concepts related to warfare have also emerged. Information Warfare, Asymmetric Warfare, Parallel Warfare, Hybrid Warfare, Unrestricted Warfare can be given as examples. These concepts, which emerged in the last period of the Cold War and especially after the Cold War, played a role in the development of a number of theories.

Although these concepts emerged in the late Cold War and post-Cold War periods, many scholars argue that similar strategies have existed historically under different names. In fact, almost all of them are as old as war itself. For hundreds, even thousands of years, the weaker side has sought various ways and methods to neutralise the technological and numerical superiority of the stronger enemy.

2500 years ago, Sun Tzu stated that ‘It is best to win without fighting’ and put forward the philosophy of ‘applying the most natural manoeuvre suitable for every possibility with the least use of force’. Although this idea is philosophical, it is also economic. Today, not only poor countries and organisations lacking technological and numerical superiority, but also rich countries and organisations, superior in every way, prioritise economy in their struggles with their rivals and consider it as a basic principle for them to achieve efficiency by providing the most benefit with the least expenditure and effort.

Zhuge LIANG, an ancient Chinese military strategist, wrote in the 3rd century BC: "..... the wise man wins the battle in advance, whereas the ignorant soldier must fight to win...... Therefore, high walls and deep water holes cannot guarantee security. Strong armour and effective weapons likewise cannot guarantee strength. If the enemy prefers to stay together, attack him where he is not ready: if the enemy is forming a line of attack, confront him where he least expects you".

The use of asymmetric methods has led the power and technology holders to search for more lethal weapons and technology. Since this would lead to more civilian deaths, it has caused theorising about whether war is justified or unjustified. The sensitivity of the Western public opinion towards human casualties in military operations increases the sensitivity of the issue day by day. No doubt, it would be a correct approach to state that the legal infrastructure of the use of force has also gained importance.

Components of the Law of War

The Law of War has three components. The first of these, “jus ad bellum”, contains the rules regarding the declaration of war, in other words, the conditions and reasons for the declaration of war. The second component, “jus in bello”, is related to actions during warfare. “jus in bello” is nowadays referred to as humanitarian law. The third component, “jus post bellum”, is concerned with the end of the war and the actions to be taken after the war. Here, the views that contain the conditions and reasons for the declaration of war are the just war idea, as it is more commonly known.

Just War Theory

It is important to explain the expressions "jus ad bellum" and "jus in bello", which constitute two different dimensions of the just war theory, in order to reveal the conceptual framework of the subject.

Jus ad bellum

The principle of jus ad bellum, which aims to determine whether war can be justified in a particular situation, sets forth certain criteria that ensure the rightfulness of war. These criteria are, in general, a just cause, lawful authority, lawful intention/good faith, the use of force must not cause harm beyond the purpose or proportionality, war must be used as a last resort, the aim must be to achieve peace, and finally, the war must have a probability of success.

Just cause is the first and most important condition of jus ad bellum. Almost all just war theorists recognise that wars waged for offensive purposes cannot be "justified". In this context, it can be argued that the just cause of a just war can only be defence. It is also a fact that this proposition can be stretched when the issue of which action is considered an unjustified attack comes to the fore. Although it is true that the only just cause of just war is defence, it is observed that just war theorists sometimes include offensive wars within the scope of defence. The only condition put forward here is that the purpose of the war, even in an offensive context, is to respond to a previous evil.

The condition of lawful authority is actually quite controversial. In general, just war theorists refer to the sovereign power of the state by lawful authority. Accordingly, it is based on the thesis that if this sovereign power is legitimate, then it will not show a tendency to arbitrary rule, and therefore this legitimate rule can be given the right to declare war. In the just war theory, the declaration of war belongs only to the lawful authority, otherwise the possibility of just war would disappear.

In the lawful intent or good faith condition, it is generally accepted that the war must be for the public good and not for personal or imperialist, unjustified interests. The just war theory does not accept the use of national interests as a pretext for offensive action, in which case the war is considered unjust. Nevertheless, it is generally recognised that there are situations in which aggression may be the only way to achieve a good intention, such as the goal of establishing peace by force.

In just war theory, the condition that the war has a chance of success is as important as just cause and good intentions. What is meant by this condition is that human and economic resources should not be wasted for an action that has no chance of success.

Although the proportionality condition is actually a condition belonging to jus in bello, as jus ad bellum, it is related to the use of force not causing harm beyond its purpose. A just war must have a just cause and, in this context, an objective, and this objective must be compatible with other principles.

Jus in bello

The principle of jus in bello, which aims to justify the use of force in war, has two important conditions: Civilian immunity and proportionality. Civilian immunity is a criterion for determining who are the right targets in war. According to the just war theory, failure to discriminate between targets would undermine the justification of war. As long as no distinction is made, non-combatants and innocents can also be targets. Combatants have joined their armies by conscious choice and are therefore appropriate targets. Non-combatants, civilians or innocents do not make such a choice, and therefore their killing is not justified.

Although just war theory prohibits the killing of civilians, it also recognises that in some cases the killing of civilians may be unavoidable. Just war theory explains this situation with the "double effect". The double effect, in a way, justifies the killing of civilians by revealing situations in which the killing of civilians in war is not intended, but accidentally occurs. The civilian/non-civilian distinction, which creates significant problems even for the classical just war theory, causes much more serious problems in the modern era with the mass wars.

The criterion that tries to determine the extent and manner of the use of violence in a just war in accordance with moral principles is proportionality. According to the proportionality criterion, the violence used in a just war must be appropriate to the objective sought to be achieved. This is different from proportionality in jus ad bellum. Proportionality in the jus in bello principle is a criterion aimed at reducing the violence and destructiveness of war.