Toward Eternal Peace: From Perpetual Peace to Sempiternal Peace via Everlasting Decision Intelligence

In the age of artificial intelligence, the ancient aspiration toward a peace that lasts has acquired new instruments and new urgency. Immanuel Kant's perpetual peace remains the deepest expression of that aspiration, a state to be reached through a federation of republics bound by treaty, after which history may rest. Two centuries of practice, however, together with the return of open conflict at the moment of writing, suggest that peace behaves less like a terminal state and more like a process that must be continuously produced. Peace is accordingly reframed. First, the genealogy of "perpetual" thinking is traced from Kant's definitory articles through modern peace research, showing that the state-view under-describes the operational work that actual stability requires. The genealogy then imports a result from command and control (C2) science, the planning, readiness, execution, assessment (PREA) loop, a process model originally developed for system-of-systems confrontation. PREA's governing principles of decision dominance through stability rather than speed offer a native grammar for peace as a maintained condition. Combining PREA with the parallel intelli- gence methods of artificial societies, computational experiments, and parallel execution (ACP) over cyber–physical–social systems (CPSS), the article proposes everlasting decision intelligence for peace. Inside its closed loop, artificial peace systems run escalation and de-escalation experiments continuously, feed prescriptions into actual institutions, and treat every restored equilibrium as input to the next planning cycle. Three separations, military–civil, human–machine, and actual–artificial, are derived as the civilizing grammar of such systems, and a five-generation account of conflict migration into Popper's artificial world is given. The framework is conceptual, and its claim ceiling is that of an agenda. Future directions, the supporting technologies they require, and the open problems against which the approach must be judged close the discussion, should peace be engineered as an unending process rather than awaited as a perpetual state.