VATICAN CITY — Pope Leo XIV, the first American pontiff, issued a stark warning against the increasing integration of artificial intelligence (AI) in military operations in his inaugural message for the World Day of Peace, released on Thursday, December 18, 2025. Titled "Peace be with you all: Towards an ‘unarmed and disarming’ peace," the document criticizes the delegation of life-and-death decisions to machines as a "destructive betrayal" of humanistic principles essential to civilization.
"Further technological advances and the military implementation of artificial intelligence have worsened the tragedy of armed conflict," the 70-year-old pope wrote. "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. This marks an unprecedented and destructive betrayal of the legal and philosophical principles of humanism that underlie and safeguard every civilisation."
Elected in May 2025 following the death of Pope Francis, Leo XIV—born Robert Francis Prevost in Chicago—has consistently advocated for ethical AI governance since assuming the papacy. His message, prepared for the Church's World Day of Peace on January 1, 2026, addresses escalating global tensions, rearmament, and the erosion of diplomacy amid rising military expenditures, which reached $2.7 trillion in 2024.
The pontiff highlighted how AI-enabled systems, including autonomous drones, robots, and predictive algorithms in weapons, diminish human accountability in warfare. Such technologies, he argued, foster a "cold and detached" approach to conflict, exacerbating instability in an era dominated by confrontational politics.
In the same document, Pope Leo XIV condemned the politicization of religion: "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." He urged religious leaders to refute such "blasphemy" through witness and teaching.
Criticizing nuclear deterrence and military power as "irrational" foundations built on "fear and domination" rather than justice and trust, the pope called for a "disarming peace" rooted in openness, humility, and evangelical values. Quoting St. John XXIII, he noted humanity's persistent fear of catastrophic war, exacerbated by modern weaponry.
The message calls on Christians and people of goodwill to cultivate peace through small acts of kindness and dialogue, countering aggression that spreads from public to private life. "Goodness is disarming," Leo emphasized, advocating protection of even the "smallest signs of peace and hope."
Released by the Dicastery for Promoting Integral Human Development, the document reflects Leo's priorities since his election as the 267th pope. His choice of name honors Leo XIII, who addressed social issues during the Industrial Revolution, drawing parallels to today's AI-driven changes.
The pope's concerns align with broader ethical debates as nations deploy AI in surveillance, cyber defense, and lethal autonomous weapons. International bodies, including the UN, have echoed calls for regulation to prevent dehumanized warfare.
In broader context, Leo XIV has addressed AI ethics in prior speeches, urging its use for human flourishing rather than domination. His message reiterates opposition to weaponizing technology, faith, or rhetoric.
As the Catholic Church prepares for World Peace Day, the pope's words challenge leaders to prioritize disarmament and trust amid geopolitical strife. The full text urges renewed commitment to international law and multilateralism for lasting peace.
