Pope Leo warns of AI risks, urges global regulation

He pointed out that significant control over digital systems, infrastructure, and data increasingly rests with major economic and technological actors rather than with states.

Pope Leo XIV has urged world leaders to slow the pace of development of artificial intelligence systems, arguing that they have become instruments of war and misinformation.

In his encyclical, the first major text issued since the beginning of his papacy, the pontiff warned that AI systems are used to spread misinformation, prioritising conflicts which could lead the world into endless wars.

An encyclical is one of the pope’s most important formal teaching documents to the Catholic Church. It is used to teach on matters of faith, morals, and social issues, and typically reveals the priorities of a pontificate to the 1.4 billion members of the Church.

Pope Leo’s document, issued on Monday, is titled Magnifica Humanitas, meaning “Magnificent Humanity.” It centres AI as its major theme, while also addressing violence, wars among countries and the transatlantic slave trade.

In the document, the first US-born pontiff warned against AI as a tool for the normalisation of war. He described it as a “troubling revival of war as an instrument of international politics”

“For this reason, the development and use of AI in warfare must be subject to the most rigorous ethical constraints, to guarantee respect for human dignity and the sanctity of life and to avoid a race to develop such arms,” he wrote in the document.

He pointed out that significant control over digital systems, infrastructure, and data increasingly rests with major economic and technological actors rather than with states — a situation some scholars describe as “technofeudalism.”

Pope Leo warned that when power is concentrated “in the hands of the few, it tends to become opaque and evade public oversight, increasing the risk of distorted forms of development that give rise to new dependencies, exclusions, manipulations and inequalities.”

The religious leader urged the “disarming” of AI systems to prevent their misuse, particularly in warfare.

He urged strong oversight of AI use by religious leaders, civil society, and the government.

Pope Leo on war, slavery

Pope Leo, who served as an American cardinal before his election to the papacy in May 2025, declared early on that he considers AI a threat to humanity.

He also criticised the US and Israel’s war on Iran and, as a result, drew the ire of President Donald Trump. PREMIUM TIMES reported that Mr Trump had attacked the Pope last month, saying he was “weak on crime” and asking him to “use common sense.”

Mr Trump also claimed the Catholic pontiff would not have been selected if Mr Trump were not in office during last year’s selection of a new pope.

“If I wasn’t in the White House, Leo wouldn’t be in the Vatican,” he wrote on Truth Social. But the Pontiff responded that Mr Trump’s attack did not sway him.

In his 235-page encyclical, Pope Leo also expressed concerns about war and violence among countries and the growing disregard for multilateral organisations.

While noting that “digital revolution is changing the nature of conflict,” he also pointed out that the “culture of power is taking hold in which the availability of resources and the ability to dominate tend to dictate the agenda and criteria for decision-making.”

“This culture of power infiltrates society, changes relationships and behaviours, and grows by normalising war, pursuing ever-greater military power, taking advantage of the crisis of multilateralism and fuelling a false realism that insists that there is no alternative,” he wrote.

The cleric also issued a historic apology for the role of the Holy See in legitimising slavery and for having failed to condemn it for centuries.

He called the slave trade era a “wound in Christian memory” and the Vatican’s record.

This is the first time a Pontiff has acknowledged the role of past popes in the European trans-Atlantic slave trade. Although many have in the past apologised for Christian involvement.