Pope Leo XIV has issued a strong warning over the expanding use of artificial intelligence in military operations, cautioning that allowing machines to make decisions over life and death constitutes a grave moral failure and a profound threat to the foundations of human civilisation.
The pontiff made the remarks in his first official message for World Peace Day, released on Thursday, December 18, ahead of the annual observance marked by the Catholic Church on January 1. In the message, Pope Leo expressed deep concern about the accelerating integration of artificial intelligence into modern warfare and the ethical consequences of delegating critical human judgments to autonomous systems.
“Further technological advances and the military implementation of artificial intelligence have worsened the tragedy of armed conflict,” the pope said. “There is even a growing tendency among political and military leaders to shirk responsibility, as decisions about life and death are increasingly delegated to machines.”
According to him, this trend represents a dangerous shift away from the moral and legal principles that have historically governed the conduct of war and protected human dignity. “This marks an unprecedented and destructive betrayal of the legal and philosophical principles of humanism that underlie and safeguard every civilisation,” Leo said.
The pope’s warning comes at a time when several countries are rapidly deploying AI driven technologies in their defence and security architectures. These include automated surveillance and targeting systems, cyber warfare tools, predictive intelligence platforms, autonomous drones and missile defence systems that rely on complex algorithms to identify threats and determine responses, often with minimal or no direct human intervention.
While proponents of military AI argue that such systems can enhance precision, reduce casualties and improve operational efficiency, critics have raised alarms about accountability, transparency and the risk of unintended escalation. Human rights organisations, ethicists and international law experts have repeatedly warned that autonomous weapons systems could violate existing humanitarian laws and make it more difficult to assign responsibility for unlawful killings or civilian harm.
Pope Leo, the Catholic Church’s first pontiff from the United States, has emerged as a vocal advocate for ethical governance of artificial intelligence since his election in May. His latest message builds on earlier calls for international cooperation to ensure that emerging technologies are developed and deployed in ways that respect human dignity and promote peace rather than conflict.
In his World Peace Day address, the pope stressed that warfare already inflicts profound suffering on civilians and societies, and that the introduction of AI into combat risks further dehumanising violence. He warned that when machines are empowered to determine targets or assess threats without meaningful human oversight, moral responsibility becomes dangerously blurred.
“Human beings must never relinquish their responsibility for decisions that directly affect human life,” he said, noting that technology should serve humanity rather than replace moral judgment. He added that ethical reflection must keep pace with technological progress to prevent innovation from becoming a tool of destruction.
Beyond the issue of artificial intelligence, the pope also used the message to criticise the growing politicisation of religion, warning against the misuse of faith to legitimise violence, nationalism and armed conflict.
“Unfortunately, it has become increasingly common to drag the language of faith into political battles, to bless nationalism, and to justify violence and armed struggle in the name of religion,” Leo said. He cautioned that such practices distort the core message of religion, which he described as a force for peace, reconciliation and respect for human life.
According to the pontiff, when religion is weaponised for political or military ends, it deepens divisions, fuels intolerance and undermines efforts to resolve conflicts through dialogue. He urged religious leaders and communities worldwide to resist such tendencies and to reaffirm their commitment to peacebuilding and coexistence.
The pope’s remarks come amid a broader global debate on the regulation of artificial intelligence, particularly in the military domain. While international discussions have been held at forums such as the United Nations Convention on Certain Conventional Weapons, efforts to establish binding rules on autonomous weapons have so far stalled, largely due to disagreements among major military powers.
Some governments argue that existing international humanitarian law is sufficient to regulate AI enabled weapons, while others insist that new frameworks are urgently needed to address the unique risks posed by autonomous systems. Advocacy groups have called for a preemptive ban on so called “killer robots,” warning that failure to act could lead to an unchecked arms race driven by artificial intelligence.
Pope Leo’s intervention adds a moral and spiritual dimension to these debates, reinforcing calls for restraint and ethical accountability. Observers say his message is likely to resonate beyond Catholic circles, particularly as concerns grow over the pace at which military technologies are advancing relative to the development of regulatory safeguards.
In concluding his message, the pontiff appealed to world leaders, policymakers and technologists to place human dignity at the centre of decision making. He urged nations to invest in diplomacy, dialogue and peacebuilding rather than relying on increasingly sophisticated weapons systems.
World Peace Day, established by Pope Paul VI in 1967, is observed annually by the Catholic Church as an opportunity to reflect on the causes of conflict and the paths to peace. This year’s message, analysts say, underscores the Church’s growing engagement with contemporary global challenges, including artificial intelligence, technological ethics and the moral responsibilities of power in an increasingly complex world.
