Kant and the Theory and Practice of International Right. Georg Cavallar

that a paradigm shift takes place in three areas of Kant’s doctrine of international right. First, it moves from the traditional focus on the right of war (ius belli) to the right directed towards peace (ius pacis). Second, Kant borrows the concept of state sovereignty from international law but reinterprets it as popular sovereignty. Finally, Kant undermines the idea of classical law of nations as almost exclusively centred on states with cosmopolitan right.

      Beyond the just-war theory

      In the eighteenth century, international law was seen as a system of interactions among sovereign states which did not see each other as criminals but as justi hostes, as potential enemies who (theoretically) shared equal rights.⁴⁶ Balthazar de Ayala (1548–84) had used iustum in the sense of ‘lawful’ or ‘legal’, pointing out that only the sovereign had the right to wage war.⁴⁷ By the eighteenth century, war was seen as a duel, as guerre en forme or ‘regular war’,⁴⁸ which had to fulfil certain formal criteria such as a declaration of war. The question of whether this war was in itself just or not was less important, or even had to be left out:

      Thus the rights founded upon the state of war, the legal nature of its effects, the validity of the acquisitions made in it, do not depend, externally and in the sight of men, upon the justice of the cause, but upon the legality of the means as such, that is to say, upon the presence of the elements constituting a regular war.⁴⁹

      This eighteenth-century understanding is fundamentally different from our present perception. Since the First World War, international law has undergone a profound change.⁵⁰ Modern international law has gradually banned war and the use of force in international relations – at least in theory. The first important document was the Kellogg–Briand Pact of 1928, followed by the Charter of the United Nations of 1945 (article 2, 4). International law has absorbed Kant’s categorical imperative to avoid war and promote peace. This imperative is expressed most clearly in an impressive passage in the Metaphysics of Morals:

      [M]oral-practical reason within us pronounces the following irresistible veto: There shall be no war, either between individual human beings in the state of nature, or between separate states … For war is not the way in which anyone should pursue one’s rights. (VI, 354)

      This veto is ‘irresistible’, or unwiderstehlich, which means that it does not allow for exceptions. The last sentence in the quotation points out Kant’s philosophical argument: war is the opposite of justice and a just, legal procedure or trial, and thus incapable of obtaining one’s rights. Kant replaces the paradigm of (a formally conducted) war by the paradigm of peace: ‘What is at stake for Kant, is not the elimination of a natural disposition in man to quarrel, but the elimination of possible juridical grounds for it.’⁵¹ This is a paradigm shift and can be explained with the help of Hobbes’s formula exeundum e statu naturali. Kant starts with a factual description: states exist ‘in their external relationships with one another … in a condition devoid of right’ (nicht- rechtlichen Zustande; VI, 344, 6–10; VIII, 354–5; VI, 312) and full of (possible) war.⁵² This seems to be a truism and a banality. In fact, however, it points at the difference between Kant and most of his contemporaries. They tended to question Hobbes’s description of the law of nations as ius inutile and his denial of any binding norms as too extreme or pessimistic. Vattel, for instance, refers to Hobbes’s ‘detestable principles’.⁵³ Kant is completely Hobbesian in his analysis of the status quo. In contrast to Hobbes, however, Kant postulates a juridical duty to leave this state of nature in the sphere of international relations as well (VI, 344, 13–14; VI, 350, 6–8; VIII, 354, 3–8).

      Kant’s philosophical predecessors in international right had a different perspective. For them, limiting wars and subjecting them to norms of conduct was crucial. This is an honourable enterprise; however, this kind of thinking might be too close to reality. Kant tries to save the dimension of ideals and anticipation in international right. Kant’s theory might be called anticipatory as it refers to something which is possible or can be realized (it does not touch upon a strict utopia or ‘nowhere’). This thinking is fully aware of the problems posed by reality, for instance the fact of state anarchy.⁵⁴ Kant combines the classical right of nations (set out by Vattel and others) with the normative ideals of peace concepts (developed in particular by Saint-Pierre and Rousseau).

      Interpreters still disagree on whether Kant’s transition from a condition of war to a juridical condition is convincing (see chapter 8). In this context, I want to emphasize one aspect, the difference between the domestic and the international level. Kant claims that in international relations, no country is entitled to end the state of nature by means of force. Kant has accepted this permissive right among individuals who enjoy their lawless freedom (VI, 256, 14–18). Perpetual peace is ‘the ultimate end of all international right’ (VI, 350, 16–17), the ‘supreme political good’ (VI, 355, 30). Still, no state is entitled to force others into a condition that might realize this highest or supreme good. Kant abandons the just-war theory. A just war, Kant contends, is a contradictio in adjecto, because it tries to determine what is lawful by means that are not lawful, namely ‘one-sided maxims backed up by physical force’ (VIII, 356–7).⁵⁵ In a full juridical condition, legislation, jurisdiction and executive are never concentrated in one person or state, and the means applied reflect the underlying legal principles.

      It might be argued that Kant’s accounts of the right to go to war and of the unjust enemy contradict my thesis of a new paradigm. Does Kant not relapse behind his own (allegedly pacifist) theory with the claim that states do have a right to go to war? A full analysis of these doctrines can be found in the respective chapters of this book (see chapters 6