The encyclical Magnifica Humanitas devotes an entire chapter to the military use of artificial intelligence. Pope Leo XIV warns that AI can “lower the threshold for the use of force” and feed a culture where “victims are reduced to a data point.” The appeal is emphatic: “No algorithm can make war morally acceptable.”
The Pope denounces how the digital revolution is changing the grammar of conflict. Alongside visible war come hybrid forms: cyberattacks, information manipulation, influence campaigns and the automation of strategic decisions. AI enters these processes as an accelerating factor, in a context where many technologies are intrinsically ambivalent: what is created to protect can quickly become an attack, and the line between protection and aggression tends to blur.
“AI does not free conflict from its intrinsic inhumanity: it can only make it faster and more impersonal, lowering the threshold for resorting to violence and turning defense into operational forecasting, with victims reduced to data. In this way, it accustoms us to the idea that violence is inevitable and only needs to be optimized.”
The condemnation of fully autonomous weapons
The Pope condemns the development of fully autonomous weapons, in which the decision to kill is delegated to automated systems. “At times people speak of ‘artificial moral agents,’ as if a machine could guarantee, more consistently than a human being, the distinction between good and evil. But moral judgment cannot be reduced to a calculation: it involves conscience, personal responsibility and recognition of the other as a person. That is why it is not permissible to entrust lethal or, in any case, irreversible decisions to artificial systems.”
The encyclical demands traceability and accountability: for every system used in warfare, the ability to reconstruct decisions must be guaranteed, so that responsibility is not dissolved “into the machine.” “The chain of responsibility must remain identifiable and verifiable: those who plan, train, authorize and deploy must be able to answer for their decisions.”
The Pope also denounces the technological arms race, with multimillion-dollar contracts between the Pentagon and OpenAI, Amazon, Microsoft, Google and Nvidia, and calls for international legislation to curb it. “AI can strengthen defense and the protection of civilians, but it can also lower the threshold for the use of force, make responsibilities opaque and feed a culture in which the enemy is reduced to a data point and the victim to ‘collateral damage.’”
The culture of power and the normalization of war
But the Pope's denunciation goes beyond autonomous weapons. The encyclical offers a diagnosis of the culture of power that allows war to be normalized. “Today we are witnessing a true paradigm shift in public discourse and in decisions to rearm, with a worrying rehabilitation of war as an instrument of international policy, while the very ethical criteria that had limited its use are being eroded.” Regional conflicts that drag on over time, escalating tensions and mutual threats become almost routine, and forms of conflict driven by territorial expansion that were believed to be a thing of the past are resurfacing.
The Pope denounces the close connection between economic interests, military apparatuses and political decisions, which produces an “armed nation” in which war seems almost a natural extension of politics. “We cannot ignore the enormous economic interests behind war. Arms industries and the countries that supply weapons benefit from a market that thrives precisely because of conflicts.”
He also denounces the loss of historical memory. “The gradual disappearance of direct witnesses to the Holocaust and the two world wars makes it easier to rewrite the past selectively or in a distorted way, in a climate where fake news and narrative manipulation cloud the lessons learned.”
The encyclical criticizes the false “realism” hiding behind this culture of power. “Behind all this lies a false ‘realism,’ based not only on the entrenched logic of force but also on a cultural and anthropological conviction, as if war were inevitably part of human nature. It has always been this way, we are told, apart from brief interludes, and it will always be so! Therefore the problem is no longer peace, lost as a reference point on the international horizon, but how and when to act militarily, while it is maintained that it would be irresponsible not to prepare for confrontation.”
Five paths of action against that culture
In the face of this culture of power, the Pope proposes five paths of action: disarming words, building peace in justice, adopting the perspective of the victims, cultivating a healthy realism, and relaunching dialogue and multilateralism. “Let us disarm words and we will help disarm the earth,” the Pope writes, taking up an expression of Francis.
Dialogue is the main instrument of coexistence among individuals and among peoples. “The vocation of diplomacy is to foster dialogue with everyone, including those interlocutors considered most ‘uncomfortable’ or not regarded as legitimate parties to negotiation.” The Holy See, through its diplomatic network, “takes up the Gospel principle of mercy as a concrete criterion of political action.”
How it compares with other global actors
A comparison with other global actors reveals the Vatican's unique position. Pope Francis had already called for a ban on autonomous weapons at the 2024 G7; Leo XIV has repeated and deepened this appeal. The European Union has established in the AI Act a ban on AI systems that exploit vulnerabilities, but it has not explicitly banned autonomous weapons. China is actively developing autonomous weapons systems and has shown little interest in international agreements limiting their development. The United States has adopted a stance of ambivalence: it acknowledges the need for some kind of regulation, but continues to invest massively in military AI. The big tech companies have taken divergent positions: Anthropic refused to give its models a “free pass” for use during the invasion of Iran; other companies, however, have signed multimillion-dollar contracts with the Pentagon.
The Vatican thus stands as the firmest and most explicit voice in condemning the military use of AI and in demanding effective human control, offering an alternative vision to the culture of power that normalizes war and violence.
