Kant on War and Peace

In his famous essay “Towards Perpetual Peace,” Kant views a federal union in the form of a voluntary coalition of states, each of which would retain its sovereign rights and should be republican, as the sole guarantee of a “perpetual peace,” i.e. the perpetual abolition of military conflicts. Just as the individuals are living in a state of nature before entering into the rightful condition via the conclusion of a contract, similarly, the condition prior to the institution of the states federation also pertains to a state of nature. And just as the contract which allows the exit from the state of nature and the establishment of the public law is an idea of reason, similarly, for Kant, “reason as the highest legislative moral power, absolutely condemns war as a test of rights and sets up peace as an immediate duty.” The aim of the present paper is to highlight Kant’s account of peace as the moral aspect of legality, i.e., the condition under which right delimits and disciplines the use of violence. In opposition to the advocates of the “just war” theories whom Kant strongly criticizes for “Jesuitism” insofar as they sanction any means for supposedly “good ends” and legitimate colonialism, Kant claims that the sole justification for initiating and the only legitimate means of conducting a “radical evil” such as war lies in the possibility of achieving peace. Kant's two fundamental principles regarding war and peace can be articulated as follows: First, the barbaric resolution of disputes can only be rejected by a state as a public legal order. Second, the sole use of force that warring states are entitled to accept is that which preserves the possibility of future peace. The latter principle anticipates both the legitimate conditions for conducting war -jus in bello- and the norms that should govern the post-war order -jus post bellum- In the sixth preliminary article of his “Perpetual Peace”, Kant condemns practices in warfare that irreversibly undermine the possibility of peace, such as "the employment of assassins (percussores) or poisoners (venefici), breach of agreements, the instigation of treason (perduellio) within the enemy state, etc.” Similarly, in the Metaphysics of Morals, Kant denounces post-war practices by victors that permanently negate the prospect of peace. He vehemently criticizes the plundering of a people by the victorious power since “it was not the conquered people that waged the war; rather, the state under whose rule they lived waged the war through the people.” Finally, Kant condemns conquerors’ efforts to divide the territory of the defeated state among themselves, since “that would be an injustice against its people, which cannot lose its original right to unite itself into a commonwealth.”