Abstract
This essay explores Immanuel Kant's perspective on war and the philosophical underpinnings of his right to "exit war." It critically examines the evolution of war from the concept of jus publicum europaeum to contemporary global conflicts marked by absolute enmity and dehumanization, where enemies are seen as existential threats rather than equal opponents. Through an analysis of key texts, including Perpetual Peace and The Metaphysics of Morals, the study discusses Kant’s ideas on "unjust enemies". It suggests that Kant’s critical realism renciles normative ideals with the realpolitik of international relations, where the drive for peace and the inevitability of war coexist in a dialectical tension. Kant’s notion of a perpetual, yet contingent, peace is revisited, highlighting the need for a practical, adaptable approach to peace that respects the sovereignty of states while fostering an international federation.