What is an encyclical?

An encyclical is a papal letter that outlines the Catholic Church's official perspective on a key topic, in this case artificial intelligence.

Why is Pope Leo XIV's call to 'disarm' AI so significant?

It is the Catholic Church's most forceful intervention in the global debate over AI warfare, labor, and society, and it risks putting the Vatican on a collision course with governments racing to deploy AI as a strategic weapon.

What did Pope Leo XIV say about the 'just war' theory?

He stated that the theory is outdated and has been used to justify any kind of war, and that no algorithm can make war morally acceptable.

Pope Leo XIV encyclical calls for disarming AI warfare

Pope Leo XIV takes aim at AI warfare, calls for artificial intelligence to be 'disarmed'

ROME, 25 May 2026

Lula Oficial / Wikimedia Commons / CC BY-SA 4.0

Summary

Pope Leo XIV released a papal encyclical on Monday calling for artificial intelligence to be 'disarmed' and barred from lethal decision-making. The document, the Vatican's strongest stance on AI, warns that the technology must not dominate humanity and risks putting the Church on a collision course with governments.

ROME, 25 May 2026

Pope Leo XIV on Monday issued a sweeping papal document calling for artificial intelligence to be "disarmed" and warning that it must never be entrusted with lethal decisions, in the Catholic Church's most forceful intervention yet into the global debate over AI warfare.

The document, an encyclical, is the highest form of papal teaching and outlines the Church's official perspective on a key topic. This encyclical, released from the Vatican, addresses the rapidly expanding role of artificial intelligence in warfare, labor, and society.

A Papal Call to 'Disarm' AI

The Pope called for the "disarming" of artificial intelligence, urging that it be prevented from "dominating humanity." His language marks a clear red line against the unfettered development of autonomous weapons.

Pope Leo stated explicitly that it is "not permissible to entrust lethal" decisions to technology, asserting that AI should never be used to make choices about who lives or dies in a conflict.

The pontiff also warned against the growing tendency to treat chatbots and other AI tools as if they were human, saying they should never be equated with people.

In one of the document's sharpest passages, Pope Leo declared that the traditional "just war" theory is now outdated. Quoting from the encyclical, he emphasized it is "important to reaffirm that the 'just war' theory, which has all too often been used to justify any kind of war, is now outdated."

The Outdated 'Just War' Theory

"No algorithm can make war morally acceptable," the Pope added, directly challenging the notion that AI could bring greater precision or ethical clarity to armed conflict.

Beyond the battlefield, Pope Leo warned of "new forms of slavery" emerging alongside the rise of artificial intelligence, hinting at the economic and social disruptions caused by AI-driven automation and surveillance.

First American Pope, Fresh Tensions

The encyclical represents the Catholic Church's most muscular entry into the high-stakes debate over how AI is reshaping global power dynamics. It risks putting the Vatican on a collision course with governments, including the United States, that are racing to integrate AI into their strategic arsenals.

Pope Leo, who is the first U.S. pope, has previously clashed with the White House over its use of religion to justify conflict. Although he did not name President Donald Trump in his Monday remarks, the encyclical's implicit criticism of AI weaponization is likely to heighten those tensions.

The intervention comes at a moment when autonomous drones, AI-guided decision-making systems, and generative AI are being tested by multiple militaries, prompting urgent ethical questions that the Pope has now placed squarely before the world's 1.3 billion Catholics.

Questions & Answers

What is an encyclical?: An encyclical is a papal letter that outlines the Catholic Church's official perspective on a key topic, in this case artificial intelligence.
Why is Pope Leo XIV's call to 'disarm' AI so significant?: It is the Catholic Church's most forceful intervention in the global debate over AI warfare, labor, and society, and it risks putting the Vatican on a collision course with governments racing to deploy AI as a strategic weapon.
What did Pope Leo XIV say about the 'just war' theory?: He stated that the theory is outdated and has been used to justify any kind of war, and that no algorithm can make war morally acceptable.