Pope Pope Leo has urged governments around the world to slow the rapid advancement of artificial intelligence, warning that unchecked technological development could intensify global conflict, spread misinformation, and push humanity toward what he described as a future of “unending war.”
The appeal was contained in his first major doctrinal document released on Monday, a nearly 43,000-word encyclical titled “Magnifica Humanitas (Magnificent Humanity)”, which outlines one of the most forceful papal interventions yet on AI, global conflict, and modern ethics.
Leo called on political leaders to take greater responsibility for regulating artificial intelligence, stressing that societies must not allow powerful technologies to be controlled solely by private interests.
“What is needed is a more active political involvement that is capable of slowing things down when everything is accelerating,” he wrote.
He also urged the creation of “robust legal frameworks, independent oversight, informed users and a political system that does not abdicate its responsibility,” warning that regulation must keep pace with rapid technological change.
The pontiff further cautioned that competition among AI companies could spiral out of control, calling for a deliberate “cooling” of the global race for technological dominance.
On the use of AI in warfare, he issued one of his strongest warnings yet, insisting that autonomous systems must never be given the power to make lethal decisions.
Any military deployment of AI, he said, “must be subject to the most rigorous ethical constraints,” adding that it is “not permissible” to delegate life-and-death authority to machines.
The encyclical also addressed broader global instability, lamenting what it described as a rising culture of violence and weakening international cooperation.
“The past 60 years have been marked by conflicts of astonishing brutality, often affecting civilian populations on a massive scale,” he wrote.
He warned that humanity is drifting into a “violent culture of power,” where peace is no longer treated as a responsibility but as a temporary pause between conflicts.
Leo also questioned the continued relevance of the traditional “just war” doctrine, saying it has increasingly been used to justify armed conflict.
“The ‘just war’ theory which has all too often been used to justify any kind of war, is now outdated,” he stated.
He further cautioned that some world leaders may even resort to war as a distraction from domestic crises, using conflict as a political tool.
The pope also condemned exploitative practices linked to the AI supply chain, describing them as “new forms of slavery,” including dangerous labour in mineral extraction and technology manufacturing.
“In some regions of the world, children and adolescents work in dangerous conditions, crushing the materials from which rare earth elements are extracted,” he wrote.
“The bodies of these people are scarred, injured and worn down so that computational flow may continue uninterruptedly,” he added.
In a rare institutional admission, he also acknowledged the Church’s historical involvement in slavery, offering an apology on behalf of the Catholic Church.
“This constitutes a wound in Christian memory,” he wrote. “For this, in the name of the Church, I sincerely ask for pardon.”
Drawing a biblical parallel, he likened unchecked technological ambition to the Tower of Babel, warning against building systems without moral grounding.
“With the heart of a shepherd and a father, I ask everyone to abandon the construction of yet another Tower of Babel and to join forces in building up the common good,” he stated.
He urged global leaders and citizens not to be overwhelmed by the scale of AI-related challenges.
“A subtle temptation may emerge, namely the thought that the problems are too big and we are too small,” he wrote. “Yet, no one is without responsibility. We all have our own areas for action.”
