The Law of War – Regulating Destruction

Author: Manasvi Kanaparthy

Student, Indian Institute of Management, Rohtak


One of the earliest mentions of the concept of justice in relation to war comes from Roman philosopher Cicero in his treatise, De republic, where he says that a war waged without cause is unjust. He goes on to say that unless that cause is ‘punishing a wrong’ or in self-defense, war is not justified. Religious texts all across the world have always dwelled on the idea of war; and the violence and destruction associated with it can be morally justified in certain circumstances. He also says that war waged in order to uphold peace is a just war. Certain kinds of wars being legitimate, justified and required is not a new concept and is seen to be repeatedly invoked by philosophers, theologians, generals and tyrants alike.

In the modern context, where justice and legality are considered to be coinciding, the concept of a just war has become less philosophical and more legal in nature. There are certain established principles in international jurisprudence that govern the legality of warfare.

[1]The principle of jus ad bellum or the just war theory relates to the cause of war, and it being a just one. There are 6 principles that justify the waging of war, according to this theory:

[2]Just cause – the country must have a just and reasonable cause to declare and wage war. The first just cause is self defense. According to existing, accepted jurisprudence, it can be justified firstly on the ground of self defense.

Although the aim and object of the United nations charter is to outlaw war and violence, [3]article 51, chapter VII of the United Nations Charter states that nothing in the charter can prevent a sovereign state from using force in self-defense. Additionally, parties to the [4]NATO treaty have expanded this right to mean collective self-defense, under article 5 of the treaty, an act of aggression against one NATO country will trigger this provision, resulting in defense and retaliation by the entire alliance.

Another justified cause for declaring war is international humanitarian intervention. It is an accepted principle of international law that military intervention in another sovereign state is justified in cases of genocide and other similar grave violations of individual rights. [5]Chapter VII of the United Nations charter deals with the circumstances and methods by which the UN and security council can intervene in the affairs and actions of a sovereign state. The interference of the international community was indeed contentious. In reality however, the acceptance of intervention as a valid cause of aggression is a rather recent phenomenon that evolved in the post-cold war period. [6]The term ‘responsibility to protect’ was evolved by the international commission on intervention and state sovereignty. The change of terminology may seem insignificant in the larger scheme of things, but it shifts the narrative in favor of a more humanitarian outlook rather than one centered around the supposed right of a country to make war. The current debate around the responsibility to protect revolves around the degree, magnitude, and timing of intervention rather than intervention itself.


[7]Right authority – This pre-condition to a just war is a more bureaucratic one than the others. The just war theory states that war must be declared and fought by a body resembling a sovereign state’s government. The authority must have control of a territory and must be governing it’s people. Additionally, the process of declaring and waging the war must be in accordance with the procedures established by the law of that region or government. The process must have legal validity and authority. And the war must have the approval or participation of the citizenry. The foundations of this component of the theory may not seem all that infallible at first glance, however, it is vital to the modern conceptions of war. For example, let us assume a group of delinquent individuals residing in a particular country commit acts of aggression on the borders of a neighboring country, it would not be considered a declaration of war by either country, for the simple reason that the group of individuals do not have the authority to do so. They are not the government and do not speak for the people of an entire sovereign nation. It is also important to note that the state of affairs in the modern world is not simple, there are internal as well as just external conflicts and sometimes, a combination of both, and so this categorization is not an ironclad one.


Right intention – This aspect is distinct from just cause, because it refers to the ulterior motives that nations may have for waging war. A country may have a strong and legitimate cause or justification for it, but may still be doing so for self-serving reasons. The question of why a war is being waged can be answered in two ways. One answer is the reason that the war is required like genocide or ethnic cleansing in the country in question, and the other answer is why exactly the other countries have decided to fight that war, like gaining territory or resources. The former is the cause, and the latter is the intention. So, if the intention behind fighting that war is self interest or destruction or a show of strength, then it is not considered a just war, because the intent behind it is not morally justified.


[8]Proportionality of force – This aspect appears in both, the jus ad bellum theory (the resort to war) and jus in bello (the conduct during war). It refers to the degree of force used in war, in comparison to the circumstances of the crisis at hand. The principle weighs the benefits against the cost of war. The ends must justify the means. The benefit that the war would bring if it was successful is weighed against the loss of life, property and resources and the attempt must be reconcilable. That would make the act, what is referred to as proportional to the crisis. Where the jus in bello principles are concerned, this principle is a very straightforward one. One wouldn’t use a nuclear warhead to defend oneself from scattered guerilla fighters. This principle evolved as a justifiable reaction to the mutual destruction that is caused by an all-out war, that if the benefit of the war is not worth the loss of life and resources then it is not a just one.


Reasonable probability of success – This aspect is a rather contentious aspect of the just war theory. As the name suggests, this caveat says that if there is no light at the end of the tunnel, a country should drop its weapons. In other words, if success or the end result is not reasonably to be expected or is not probably achievable by the effort, this makes it a futile effort for which the loss of life, property and resources is not justified, making the war an unjust one. As an extension to the requisite of proportionality, if the legitimate end object is not achievable, there is no point in making the painful effort.

Rule of Last Resort – [9]Chapter VI of the United Nations charter, more specifically article 33 under it, emphasizes the primacy given to resolution of disputes in a peaceful and non-confrontational manner. The article says that the international community ought to first address the conflict by way of conciliation, mediation, judicial settlement etc. On the failure of these means, the security council is required by the charter to hold a formal enquiry into whether the continuance of the dispute would harm the humanitarian interests of the people, and only if the result of the enquiry is in the affirmative, can armed action be considered. If armed action is being considered by a country, it needs to be put to the security council and only with the consensus of the international community can such action be resorted to. This demonstrates that, war or armed action should only be considered as the very last resort, in the event that all other resolution fails.


Jus in bello

The very essence of war being destruction, it seems absurd to include the concept of justice in the course of warfare as a prerequisite. However, following the very real destruction of the second world war, the effects of the proxy wars in the cold war period and the threat of nuclear war in the 1990s exemplified the need for a body of jurisprudence dealing exclusively with regulating the actions of states already at war. However, it cannot be understood in isolation, but in consonance with the theory of jus ad bellum. This would mean that unless jus in bello is satisfied, the war would be unjust. So much so that even if the preconditions for a just war were satisfied under jus ad bellum, the war would be stripped of its legitimacy if jus in bello was disregarded.

[10] The concept of international humanitarian law deals with the law of warfare or jus in bello. It encompasses the set of principles that regulate the conduct of states already at war with regard to the loss of life and resources caused by them. This theory deals with the way the war is being fought. There are two principles under this theory.

Firstly, the principle of discrimination requires the states in conflict to distinguish between civilians and combatants while carrying out acts of aggression. Similar distinction is required to be made between infrastructure and resources as well. Collateral loss of life of non-combatants was outlawed under this principle.

Secondly, the principle of proportionality which has previously been mentioned, applies in this context. It requires the force used to be proportionate with the existing conditions. Use of excess force under the guise of combat cannot be justified.

Jus post bello

[11]The principle of jus post bellum is a rather recent conception in the international humanitarian jurisprudence. It relates to the post war restoration and reconstruction of the vanquished state and it’s government. Broadly, it’s the treatment of the country and its citizens after a loss. It is said to be a modern conception because according to the existing doctrine and prevailing notions of the ethics of warfare as described above, require that the damage be minimized as far as possible. Conquering powers are no longer permitted to wreak havoc upon the losing side and abandon them in the wake of their victory, as is evident from the above discourse. So, restoring the destroyed nation to its pre-conflict state is also now considered a part of waging a ‘just war’, which seems to be the goal. Establishing sound, sustainable and fair governments with the consensus of the population and aiding the economic reconstruction of such territories is essential.


In essence, the object and subject of this discussion comes down to one vital observation. That conceptions of warfare, even though as old as civilization itself, have evolved and are evolving as we speak. And as is quite evident from the current pattern, traditional warfare is quickly losing the glory and acclaim it once enjoyed, or even approval for that matter. The conquering ideology is being sacrificed in favor of one that mandates peace, dialogue and other more civilized methods of managing international affairs.

[1] International Committee of the Red Cross. 2015. What are jus ad bellum and jus in bello?. [online] Available at: <https://www.icrc.org/en/document/what-are-jus-ad-bellum-and-jus-bello-0> [Accessed 5 July 2022]. [2] Lieblich, E., 2019. The Facilitative Function of Jus in Bello. SSRN Electronic Journal,. [3] U.N Charter, art 51, 26 june 1945, U.N.T.S [4] North Atlantic Treaty(Washington Treaty), art 5, 4 april 1949 [5] U.N Charter, chap VII, 26 june 1945 U.N.T.S [6] Holmes, J., 2014. Responsibility to Protect. Global Responsibility to Protect, 6(2), pp.126-145. [7] Schmitt, M., 2003. International Law and the Use of Force: The Jus Ad Bellum. Connections: The Quarterly Journal, 02(3), pp.89-97. [8] Hong, K., 2017. Hugo Grotius’ Theory of Just War: Jus ad bellum. Korean Journal of Law and Society, 56, pp.245-271. [9] U.N Charter, chap VI, 26 june 1945 [10] Yip, K., 2022. ‘Separation’ between jus ad bellum and jus in bello as Insulation of Results, not Scopes, of Application. SSRN Electronic Journal,. [11] Stahn, C., 2006. 'Jus ad bellum', 'jus in bello' . . . 'jus post bellum'? -Rethinking the Conception of the Law of Armed Force. European Journal of International Law, 17(5), pp.921-943.

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