Just War Theory Faces a New Era of Technology

## The Evolution of Just War Theory Just war theory has been a cornerstone of international relations for centuries, providing a framework for judging the morality of war. Developed by St. Augustine and systematized by Thomas Aquinas, the theory has been applied by Western militaries to constrain the use of force. However, with the advent of artificial intelligence and autonomous weapons, the theory is facing a new era of challenges. ## The Challenge of Autonomous Weapons Pope Leo XIV's encyclical, *Magnifica Humanitas: On Safeguarding the Human Person in the Time of Artificial Intelligence*, has sparked a debate about the relevance of just war theory in the age of autonomous weapons. The pope argues that the theory has been abused and is now outdated, but experts disagree. They argue that the theory requires an update rather than retirement, as it provides a shared standard for judging the morality of war. ## The Need for an Update Just war theory has been criticized for its inability to address the complexities of modern warfare, particularly the use of autonomous weapons. The theory's criteria, such as the need for a just cause and the right intention, are no longer sufficient to constrain the use of force in an era of machine-speed decision cycles. Experts argue that the theory must be updated to address the risks of escalation, diffusion, and dirty hands associated with the use of autonomous weapons. ## The Role of Artificial Intelligence Artificial intelligence is changing the nature of warfare, making it easier to start and harder to control. Autonomous weapons can make decisions without human intervention, creating additional layers between decision-makers and the killing. This raises concerns about accountability, as machines are incapable of mercy and other human dispositions that make war a little more humane. ## The Pope's Encyclical Pope Leo XIV's encyclical provides a framework for constraining the use of autonomous weapons. The pope demands a chain of responsibility that is identifiable and verifiable, running from those who design and train a system to those who authorize and employ it. He also insists on a moral timeframe for judgment, warning that speed and efficiency should never be the supreme motivating force for the irreversible decisions made in the context of war. ## The Future of Just War Theory The debate sparked by Pope Leo XIV's encyclical highlights the need for an update of just war theory. Experts argue that the theory requires a rethink for modern war, one that takes into account the complexities of autonomous weapons and artificial intelligence. The future of just war theory remains uncertain, but one thing is clear: it must evolve to address the challenges of the 21st century. ## The Importance of Accountability Accountability is a critical feature of any normative regime's survival. In the context of autonomous weapons, accountability is essential to prevent the misuse of technology and to ensure that those responsible for the use of force are held accountable. The pope's encyclical emphasizes the need for a chain of responsibility that is identifiable and verifiable, highlighting the importance of accountability in the use of autonomous weapons. ## The Challenge of Machine-Speed Decision Cycles Machine-speed decision cycles amplify the risk of escalation, diffusion, and dirty hands associated with the use of autonomous weapons. The Pentagon's Responsible AI Strategy demands a chain of accountability, but enforcing it is harder when machines mediate the act. The pope's encyclical warns that speed and efficiency should never be the supreme motivating force for the irreversible decisions made in the context of war, highlighting the need for a moral timeframe for judgment. ## Conclusion Just war theory is facing a new era of challenges with the advent of artificial intelligence and autonomous weapons. Pope Leo XIV's encyclical has sparked a debate about the relevance of the theory, but experts argue that it requires an update rather than retirement. The theory must evolve to address the complexities of modern warfare, particularly the use of autonomous weapons. The future of just war theory remains uncertain, but one thing is clear: it must adapt to the changing nature of warfare.