Joint declaration signed in Geneva against use of AI in warfare
The World Council of Churches, joined by 225 other signatories, signed a joint declaration in Geneva urging technology firms and governments to stop supplying AI systems for use in the military kill chain. The declaration demands measures to prevent AI from contributing to violations of international humanitarian law and human rights, warning that AI can dilute human responsibility in lethal decisions. It cites rapid target generation by U.S. and Israeli forces as increasing the speed, scale, and destructive force of strikes, potentially undermining the principles of distinction, proportionality and precaution. The initiative follows Pope Leo XIV’s encyclical "Magnifica Humanitas" calling for disarming AI and was organized by the UN Office for Disarmament Affairs.
3 months ago
The World Council of Churches, together with 225 NGOs, experts and tech‑company representatives, signed a joint declaration in Geneva urging an immediate halt to the development and supply of artificial‑intelligence systems for military use, echoing Pope Leo XIV’s recent call to “disarm AI.” 1
The declaration was adopted at a United Nations Office for Disarmament Affairs meeting on AI in the military domain held in Geneva from 15–17 June 2026. 1
Pope Leo XIV’s encyclical Magnifica Humanitas (May 2026) had previously urged the global community to “disarm AI,” framing the issue as a moral and ethical imperative for the Church. 1
The signatories argue that AI‑driven target generation increases the speed, scale and intensity of lethal strikes, citing recent U.S. operations against Iran and Israeli use of similar systems. 1
They warn that reliance on AI dilutes human responsibility, obscures accountability and may conceal international crimes behind a false sense of algorithmic objectivity. 1
Large language models used for target prioritisation are said to undermine the principles of distinction, proportionality and precaution required by international humanitarian law. 1
The declaration urges technology firms to avoid contracts with any military actors or armed groups that could violate international law. 1
Governments are asked to halt the use of AI tools, including LLMs, in targeting operations and to provide transparent reporting on any AI deployment in hostilities. 1
The document aligns with Pope Leo XIV’s ethical stance that the development of autonomous killing technologies threatens human dignity and the moral fabric of warfare, reinforcing the Church’s call for “meaningful human control” over life‑and‑death decisions. 1
"Assess Catholic ethical guidance on AI’s role in armed conflict."
Catholic moral teaching does not treat “AI” as an automatically good or bad technology; it assesses AI by how it is used, especially when it touches the decisive moral territory of armed conflict, where human life, moral responsibility, and compliance with law must remain safeguarded. In the Church’s current guidance, the central ethical alarm concerns lethal autonomous weapons systems—and more generally any move toward delegating life-and-death decisions to machines—while encouraging the use of AI for peace and human development under meaningful human control and rigorous ethical scrutiny.
A consistent Catholic premise underlies the Church’s approach: technology must remain guided by the primacy of the human person, including conscience and freedom, so that human intelligence—not algorithmic processes—“responsibly determines” innovation and its limits.
In this light, the Church judges AI in warfare according to whether it preserves the uniquely human capacity for moral judgment and ethical decision-making. Pope Francis states the point bluntly in the context of lethal autonomy:
“Nor can we reduce [the unique human capacity for moral judgment and ethical decision-making] to programming a machine, which as ‘intelligent’ as it may be, remains a machine.”
This is not merely sentimental anthropology; it grounds an ethical requirement: weapon systems must be subject to adequate, meaningful and consistent human oversight, because moral responsibility cannot be transferred to a non-responsible tool.
The Church ties this directly to governance. Pope Francis at the G7 insists:
“No machine should ever choose to take the life of a human being.”
And Pope Leo XIV (building on this trajectory) frames AI as needing to be “disarmed,” i.e., freed from logics turning it into an instrument of “domination, exclusion and death,” because “decisions about technology must never be separated from conscience and responsibility.”
The Church’s strongest negative assessment is reserved for Lethal Autonomous Weapon Systems (LAWS)—systems capable of identifying and striking targets without direct human intervention. In the Vatican’s recent doctrinal note, LAWS are described as a “cause for grave ethical concern” precisely because they lack the human capacity required for moral judgment.
The Holy See’s UN position adds an additional juridical-moral claim: LAWS “can never be morally responsible subjects capable of complying with international humanitarian law.”
So the ethical problem is double:
Pope Francis also highlights a moral-psychological dynamic: remote control and autonomy can reduce the perception of devastation and dilute the burden of responsibility, producing “a cold and detached approach” to war’s tragedy.
This matters ethically because Catholic just-war reasoning depends on the seriousness of judgment before violence is used, and on the realistic recognition of the evils inflicted.
The Church worries that autonomous weapons can make war more “viable,” which tends to work against the principle of war as a last resort in legitimate self-defense. Vatican guidance warns that autonomy may increase war’s instruments beyond the scope of human oversight and contribute to destabilizing escalation:
Pope Francis further notes that sophisticated weapons could end up “in the wrong hands,” facilitating terrorism or destabilizing legitimate governments—meaning the danger is not only technical but social and political.
The Church’s guidance is not merely “be careful”; it proposes a concrete ethical standard: introduce ever greater and proper human control over the choices associated with lethal force.
The emphasis on “effective and concrete” control implies that oversight cannot be symbolic or delayed; it must be real enough to preserve human agency for moral discernment.
Pope Francis calls for reconsideration and ultimately a prohibition on the use of devices like lethal autonomous weapons, beginning with the commitment to human control.
At the international level, the Holy See also urges a moratorium on the development and use of LAWS pending negotiation of a legal instrument that:
Pope Francis calls for ethical considerations “from the very beginning of research” and continuing through the phases of:
describing this approach as “ethics by design.”
That matters for armed conflict because weapons systems are not only “deployed”; they are built through institutional decisions that shape risk and accountability long before deployment.
The Church also recommends multilateral, legally binding approaches. Pope Francis urges the global community to adopt “a binding international treaty” regulating AI’s development and use, with the aim of both preventing harmful practices and encouraging best practices.
The Church further insists regulation must be shaped by human values (e.g., inclusion, transparency, security, equity, privacy, reliability) and by voices of the poor and powerless who are often excluded from decision-making.
Catholic ethics does not abolish legitimate defense; it subjects war to strict moral conditions.
The Catechism teaches that all citizens and governments are obliged to work to avoid war, while also recognizing a right to lawful self-defense when peace efforts have failed and no effective international authority exists.
The Catechism lists traditional just-war elements: the damage by the aggressor must be lasting, grave, and certain; other means must be impractical or ineffective; there must be serious prospects of success; and using arms must not produce evils and disorders graver than the evil to be eliminated.
In this framework, AI’s ethical risk is not only what it does to a battlefield; it also threatens the moral structure of decision-making that just-war doctrine requires. Delegating life-and-death choices to machines, or enabling war with less perceived responsibility, directly undermines the “rigorous consideration” and prudential discernment the Church expects when violence is contemplated.
The Catechism condemns as a crime against God and man any act of war directed to indiscriminate destruction of whole cities or vast areas with inhabitants.
While the provided sources do not enumerate how AI targeting systems affect discrimination/proportionality, the Church’s broader concern about meaningful human control and compliance with international humanitarian law indicates that AI cannot be ethically insulated from these core legal-moral issues.
The Catechism emphasizes the evils and injustices war brings, and the Church’s prayer asking deliverance from “famine, pestilence, and war,” grounding a moral duty to avoid war as much as reasonably possible.
In that context, the Church’s warning that autonomy can make war easier and escalate arms races is morally significant: it suggests that certain deployments may increase the likelihood of war rather than constrain it.
The Church does not deny that AI can have constructive roles. In the Vatican’s note, AI’s analytical abilities are said to “help nations seek peace and ensure security,” while the “weaponization of Artificial Intelligence” is described as highly problematic.
Additionally, Pope Francis envisions AI applications that:
while insisting that “the most advanced technological applications should not be employed to facilitate the violent resolution of conflicts, but rather to pave the way for peace.”
So, Catholic ethical guidance is best read as a conditional ethic: AI can serve human purposes, but when it moves into lethal, autonomous decision-making, the Church sees an irreducible problem—machines cannot bear moral responsibility, and the moral meaning of war is destabilized when human judgment is removed.
Catholic ethics treats AI’s role in armed conflict as morally permissible only insofar as it remains human-centered, preserves meaningful human control over lethal force, supports international humanitarian law through real accountability, and is governed by ethical scrutiny oriented to human dignity and the common good—with lethal autonomy (LAWS) singled out as demanding prohibition and moratorium due to the loss of moral responsibility and heightened risks to peace.