International Law and the Use of Force

Cases and Materials

Ralph Janik

• Publisher: Routledge
• Year: 2019
• ISBN:
  9780429490620
• Edition: 1
• Topic: Diritto
• Subtopic: Teoria e pratica del diritto

This book introduces key issues on the use of force while also providing a detailed analysis of technological developments and recent legal discussions in the field.

The author examines areas such as support for rebel groups, the concept of humanitarian intervention, the Responsibility to Protect and recent conversations around the fight against the "Islamic State" in a clear and accessible manner, through a thorough presentation of relevant cases and materials.

This book is essential reading for students studying force and its intersection with international law.

1 The history of the ius ad bellum

Tracing the historic roots of the contemporary legal regime on the use of force is a complex affair. At the end, just like when describing the history of international law as such, it all comes down to the viewpoint and the definitions of war and law. If one understands war as a violent confrontation between different groups, it is as old as mankind, while some rudimentary legal rules on the use of force were already present in ancient Israelite law, the Greek city-states and Rome.¹

However, modern thinking on the ius ad bellum has started with just war theory, which was slowly but steadily superseded by positivism and the conceptualization of war as a sovereign prerogative. In the early and mid-twentieth century, then, the two world wars paved the way for the Utopian strain of thought we commonly associate with Immanuel Kant’s idea of perpetual peace and the corresponding prohibition on using force.

I Just war theory

Just war theory is commonly associated with Augustine, the originator of this thinking, who was later followed by Thomas Aquinas, the school of Salamanca, Hugo Grotius, Alberico Gentili and Cornelis van Bynkershoek—to include just a small sample of the prominent names dealing with war and peace during this period.²

Augustine identified the three basic principles for a just war: right authority (auctoritas), just cause (iusta causa) and the right intention (recta intentio).

Auctoritas requires that the war must be waged by a sovereign and legitimate (not in a democratic sense, however) ruler and not by private individuals or groups such as robbers. Iusta causa means that there has been a preceding violation of the rights of the party resorting to war. While for Augustine the mere injury was sufficient, Thomas Aquinas further required fault on the part of the wrongdoer and the corresponding need for punishment. The overarching aim is the preservation of peace and justice. The right intention, lastly, requires the old question of bad versus evil—a precondition that may, as Gentili noted, be objectively present on both sides of a war. Hence, it is often difficult to judge who is right and who is wrong, even more so if each party is making this determination for itself. In this sense, Gentili was arguably the first thinker to differentiate between the legal aspects of war on the one hand and metaphysical, theological, moral and ethical assumptions on the other.

Grotius, then, is considered the thinker who transposed just war theory into (early) modern international law. As a witness to the devastating Thirty Years’ War ravaging Europe from 1618 to 1648, he emphasized that war should be declared and only resorted to as the ultima ratio even if there was a just cause. In so doing, third parties could act as impartial arbitrators. In this regard, he also set out to overcome the problem of determining an objective standard to distinguish between righteous and non-righteous wars by identifying a list of just causes: self-defense, recovering stolen property and punishment.³ In addition, he explicitly mentioned conquest and self-imposed tutelage against the will of those affected (violations of the right to self-determination, to put it in contemporary legal terms) as examples of unjust causes. Adding to his thought, Samuel Pufendorf then elaborated on the practical validity of the emphasis on the ultima ratio requirement by requiring negotiations. In contrast to Grotius, uninvolved parties should adopt a stance of strict neutrality, e.g. by permitting warring factions to pass through their territory instead of weighing in on the righteousness—the more parties involved in a dispute, the worse.

Christian Wolff, then, can be considered as the first thinker to separate natural law and the notion of justice from positive law as rules created and voluntarily adhered to by states. From then on, legal thinking increasingly shifted towards positivism: nemo iudex in sua causa (no state may objectively determine whether its actions are just or not). Natural law has long been criticized for being out of touch with reality. Somewhat finishing the work started by Wolff, Emer de Vattel then can be seen as the undertaker of natural law thinking in inter-state relations. He further solidified the thought of states as moral persons.⁴ Wars no longer need to be inherently just since he transposed Hobbes’s assumptions on the inherently hostile environment caused by the absence of a central power—the Leviathan—in the state of nature to the international level. States themselves are sovereign to decide to which rules they want to be bound and whether they would wage war or accept the outcome of a war. As such, de Vattel stands right next to Hegel, who not much later explicitly rejected the binding character of international rules altogether, as one of the great “deniers of international law”.⁵

II War as a sovereign right

The rise of legal positivism during the nineteenth century led to the abandonment of moral considerations and just war theory. On the one hand, states emphasized their sovereignty and the prohibition of others to meddle in their internal or external affairs. On the other hand, war was generally considered as a prerogative of sovereign states. This contradiction was generally resolved in favour of the latter. Due to the anarchic structure of the international system—the “Hobbesian trap”—writers of this period considered war an inevitable aspect of self-help. The main textbooks from the nineteenth century are particularly instructive in this regard as they often contain specific chapters on the different reasons to wage war, spanning from self-defense or self-preservation to the protection of nationals, wars on “religious grounds” (usually the protection of Christians abroad, in particular in the Ottoman empire) and wars in the name of upholding the balance of power. War was an essentially political matter, not a legal one. Nevertheless, it would be wrong to simply assume, as many did, that there were no legal rules on waging war during the nineteenth and early twentieth centuries at all.⁶ Numerous textbooks from this period show that there were indeed certain considerations to be made: above all, the extensive right and duty—towards a state’s own population—of self-preservation, which had to be weighed against the robust understanding of sovereignty during this era. Examples of this thinking can be found in Henry Wheaton’s Elements of International Law from 1836, Robert Phillimore’s Commentaries on International Law from 1854, W. E. Hall’s Treatise on International Law from 1895, John Westlake’s International Law from 1904, and the first edition of Lassa Oppenheim’s famous International Law textbook from 1905.

Henry Wheaton, Elements of International Law (Stevens and Sons 1836/1904), excerpts from Chapter II

Rights of Independence

Of the absolute rights of states, one of the most essential and important, and that which lies at the foundation of all the rest, is the right to self-preservation. It is not only a right with respect to other states, but a duty with respect to its own members, and the most solemn and important which the state owes to then. This right necessarily involves all other incidental rights which are essential as means to give effect to the principal end… .

The independent societies of men called states acknowledge no common arbiter or judge, except such as are constituted by special compact. The law by which they are governed, or profess to be governed, is deficient in these positive sanctions which are annexed to the municipal code of each distinct society. Each state has therefore a right to resort to force as the only means of redress for injuries inflicted upon it by others, in the same manner as individuals would be entitled to that remedy were they not subject to the laws of civil society. Each state is also entitled to judge for itself what are the nature and extent of the injuries which will justify such a means of redress.

[416f] The right of making war, as well as of authorizing reprisals, or other acts of vindictive retaliation, belongs in every civilized nation to the supreme power of the State… . voluntary or positive law of nations makes no distinction … between a just and an unjust war. A war in form, or duly commenced, is to be considered, as to its effects, as just on both sides. Whatever is permitted, by the laws of war, to one of the belligerent parties, is equally permitted to the other.

Robert Phillimore, Commentaries on International Law. Vol. I (T. & J. W. Johnson 1854), CXLIV, CXLVI

CXLIV. From the first proposition—namely, that States are recognised as moral persons—seem to be more especially derived the rights incident to Independence, which are the following:

• 1 The right to a Free Choice, Settlement, and Alteration of the Internal Constitution and Government without the intermeddling of any foreign State.
• 2 The right to Territorial Inviolability, and the free use and enjoyment of Property.
• 3 The right of Self-preservation, and this by the defence which prevents as well as that which repels attack.
• 4 The right to a free development of national resources by Commerce.
• 5 The right of Acquisition, whether original or derivative, both of Territorial Possessions and of Rights.
• 6 The right to absolute and uncontrolled jurisdiction over all persons and things within, and in certain exceptional cases without, the limits of the territory. Under this head may be considered the status of Christians in Mohametan or Infidel countries, not being subjects of those countries, and the question of Extradition of criminals.

CXLVI. The limitations which the abstract rights of one nation may receive in their practical exercise, from the existence of similar rights in another nation, will be considered in a chapter on the doctrine of intervention… .

The reason of the thing and the practice of nations appear to have sanctioned this Intervention in the following cases,

• I Sometimes, but rarely, in the domestic concerns and internal right of Self-Government, incident, as we have seen, to every State.
• II More frequently, and upon far surer grounds, with respect to the territorial acquisitions or foreign relations of other States, when such acquisitions or relations threaten the peace and safety of other States.

In the former case the just grounds of Intervention are

• 1 Self-Defence, when the Domestic Institutions of a State are inconsistent with the peace and safety of other States.
• 2 The Rights and Duties of a guarantee.
• 3 The Invitation of the Belligerent Parties in a civil war.
• 4 The Protection of Reversionary Right or Interest.

In the latter case the just grounds of Intervention are

• 5 To preserve the Balance of Power; that is, to prevent the dangerous aggrandizement of any other State by external acquisitions.
• 6 To protect Persons, subjects of another State, from persecution on account of professing a Religion not recognised by that State, but incidental with the Religion of the Intervening State.

W. E. Hall, Treatise on International Law (4th edn, Clarendon Press, 1895), pp. 57 and 297

[page 57] Even with Priority of individuals living in well-ordered communities the right of self-preservation is absolute in the last resort. A fortiori it is so with states, which have in all cases to protect themselves, over the If the safety of a state is gravely and immediately threatened either by occurrences in another state, or aggression prepared there, which the government of the latter is unable, or professes itself to be unable, to prevent, or when there is an imminent certainty that such occurrences or aggression will take place if measures are not taken to forestall them, the circumstances may fairly be considered to be such as to place the right of self-preservation above the duty of respecting a freedom of action which must have become nominal, on the supposition that the state from which the danger comes is willing, if it can, to perform its international duties.

Whether there is any other right or duty which has priority of the right of independence so long as a state endeavours, or profess that it endeavours, to carry out its international duties is, to say the least of it, eminently doubtful, especially considering that no guarantees exist tending to limit the occurrence of such interference to due occasions, or to secure that it shall be used only for its ostensible objects. The subject will be touched upon elsewhere.

§ 12. When a state grossly and patently violates international law in a matter of serious importance, it is competent repress or to any state, or to the body of states, to hinder the wrong-doing from being accomplished, or to punish the wrong-doer, of law. Liberty of action exists only within the law. The right to it cannot protect states committing infractions of law, except to the extent of providing that they shall not be subjected to interference in excess of the measure of the offence; infractions may be such as to justify remonstrance only, and in such cases to do more than remonstrate is to violate the right of independence. Whatever may be the action appropriate to the case, it is open to every state to take it. International law being unprovided with the support of an organised authority, the work of police must be done by such members of the community of nations as are able to perform it. It is however for them to choose whether they will perform it or not. The risks and the sacrifices of war with an offending state, the chances of giving umbrage to other states in the course of doing what is necessary to vindicate the law, and the remoter dangers that may spring from the ill-will produced even by remonstrance, exonerate countries in all cases from the pressure of a duty.

[page 297]§ 88. Intervention takes place when a state interferes in the relations of two other states without the consent of both or either of them, or when it interferes in the domestic affairs of another state irrespectively of the will of the latter for the purpose of either maintaining or altering the actual condition of things within it. Prima f...