Pope Leo XIV’s new encyclical Magnifica Humanitas is ostensibly about artificial intelligence and the human person, but its most arresting claim comes in a section on war. “Today, more than ever,” Leo writes, “without prejudice to the right to self-defense in the strictest sense, 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important to reaffirm that the ‘just war’ theory, which has all too often been used to justify any kind of war, is now outdated”.
An evangelical Anglican can grant much of Leo’s warning. Modern war is increasingly mechanized, opaque, and dehumanizing. Leo is right to warn that autonomous weapons make war “more feasible” and “less subject to human control,” and he is right that “No algorithm can make war morally acceptable”. AI targeting, cyberattacks, propaganda, surveillance, and automated decision-making can all blur responsibility and hide the human face of the victim.
But Leo’s conclusion does not follow. If just war theory has been abused, the answer is not to declare it obsolete. The answer is to teach it more rigorously, apply it more severely, and refuse to let states baptize their ambitions in Christian language.
The Anglican formularies begin with a firm premise. Article XXXVII of the Thirty-Nine Articles says that lawful civil rulers may “restrain with the civil sword the stubborn and evil-doers,” and then adds the sentence pacifists cannot easily assimilate: “It is lawful for Christian men, at the commandment of the Magistrate, to wear weapons, and serve in the wars”. That is not a reluctant modern concession. It is part of Anglicanism’s Reformation settlement.
The point is not that war is good. The point is that military service is not inherently sinful. Article XXXVII rejects the claim that Christian discipleship requires pacifism as a universal rule. It also rejects private violence and freelance vengeance, because the authority to bear the sword belongs to the magistrate and not to the individual.
Evangelical Anglican commentary has normally read the Article in precisely this way. Church Society’s exposition quotes Article XXXVII’s statement that Christian men may “wear weapons, and serve in the wars,” and explains that military personnel “do not exercise authority in their own right” but act under lawful public authority. The same commentary stresses that civil authority remains “subject to the critical authority of the word of God,” which is exactly why the Article is not a blank check for the state.
The North American Anglican’s exposition of Article XXXVII makes the same point by quoting the Article’s authorization of magistrates to “restrain with the civil sword the stubborn and evil-doers” and its declaration that Christians may “wear weapons and serve in the wars”. It also notes that the American revision omitted the English Article’s specific sentences on capital punishment and Christians bearing arms, while preserving the broader claim that the civil magistrate has authority “in all things temporal” and that Christians owe respectful obedience to legitimate civil authority.
That distinction matters. An evangelical Episcopalian does not put Lambeth resolutions or General Convention statements on the same level as Scripture, the Prayer Book, the Articles, and the Ordinal. Lambeth may admonish, warn, and give counsel. It does not revise the Articles by press release.
This is where the Anglican/Episcopalian response to Pope Leo should be clear. The tradition does not say, “war is now impossible for Christians.” It says something more difficult: war may be lawful under public authority, but only within the moral judgment of God, under strict restraint, and never as a work of hatred, conquest, revenge, or national self-worship.
The Prayer Book gives this doctrine its devotional atmosphere. In the prayer “For Peace,” Episcopalians ask God for that perfect kingdom “in whose perfect kingdom no sword is drawn but the sword of righteousness, no strength known but the strength of love. In the prayer “For Peace Among the Nations,” the Church asks God to guide nations “into the way of justice and truth” and establish “that peace which is the fruit of righteousness”. In the prayer “For our Enemies,” Episcopalians remember that Christ “commanded us to love our enemies” and pray to be delivered from “hatred, cruelty, and revenge”.
That is not pacifism. It is Christian moral realism. The magistrate may bear the sword, but Christians may not love the sword. The soldier may serve lawfully, but he may not hate his enemy. The state may defend the innocent, but it may not confuse its interests with the kingdom of God.
Lambeth’s anti-war language belongs inside that framework, not above it. The 1978 Lambeth Conference repeated the older Anglican claim that “war as a method of settling international disputes is incompatible with the teaching and example of our Lord Jesus Christ”. It called modern war technology “the most striking example of corporate sin and the prostitution of God’s gifts,” condemned violence and threats of violence, and urged Christians to engage in “non-violent action for justice and peace”.
An evangelical Episcopalian can affirm the force of that warning without treating it as a repeal of Article XXXVII. Lambeth is right that war as a normal instrument of international settlement is contrary to Christ. Lambeth is right that modern war easily becomes corporate sin. Lambeth is right that Christians must examine their complicity with violence. But Lambeth does not make unlawful what the Articles declare lawful.
The Episcopal Church’s own teaching is more balanced than a simple pacifist reading would suggest. In 2003, General Convention called Episcopalians to “seriously consider and utilize the Just War criteria developed over the centuries,” especially when discussing war and preemptive strikes. The resolution listed just cause, comparative justice, legitimate authority, right intention, probability of success, proportionality, and last resort, and said these criteria “taken as a whole must be satisfied in order to override the strong presumption against the use of force”.
That is exactly the point Pope Leo’s sentence risks obscuring. Properly taught, just war theory is not a warrant for war. It is a presumption against war. It is meant to prevent the Christian conscience from being recruited into every patriotic emergency and every fashionable crusade.
The Episcopal Church’s educational material on pacifism also recognizes this tension. It says that “in addition to the Just War tradition,” Episcopalians should study pacifism, while acknowledging that the Church has also “embraced the Just War tradition”. It quotes the 2003 resolution’s admonition that, when legitimate civilian authority determines war is justified, Christians must recall Christ’s command to love enemies, discern participation or refusal with “deep reflection and prayer with humility,” and, if they participate, do so “with great reluctance, always seeking God’s mercy and forgiveness”.
An evangelical Anglican criticism of Leo’s formulation would therefore be simple. Abuse does not abolish use. Scripture has been abused. The sacraments have been abused. Episcopacy has been abused. The language of justice has been abused. That does not make them outdated. It means the Church must recover their right use.
The same is true of just war. The criteria of just cause, legitimate authority, right intention, proportionality, discrimination, and last resort are not relics from a simpler age. They are precisely the questions Christians must ask in an age of drones, algorithms, cyberwar, and autonomous weapons. Who is responsible? What authority has acted? Are civilians protected? Is the force proportionate? Have peaceful alternatives truly been exhausted? Can this action aim at peace rather than vengeance?
If modern war makes those questions harder to answer, that is an argument for applying the doctrine more stringently, not for abandoning it. Indeed, without just war reasoning, the Church risks leaving Christians with only two options: absolute pacifism or the raw command of the state. Anglicanism, at its best, has refused both.
Pope Leo is right to condemn the moral evasions of modern warfare. He is right to see that AI can distance the decision-maker from the dead. He is right to warn that the rhetoric of justice can be turned into a machine for blessing violence. But we should say that the answer is not to call just war theory outdated. The answer is to recover it as a severe Christian discipline.
Article XXXVII still stands. The Prayer Book still teaches us to love our enemies. Lambeth still warns that war as a method of settling disputes contradicts Christ. General Convention still calls Episcopalians to use just war criteria under a strong presumption against force. Taken together, these sources do not give Christians a theology of military enthusiasm. They give us a theology of lawful force under judgment.
That is the Anglican answer to Pope Leo. Just war theory is not obsolete. It is neglected, softened, politicized, and abused. The task before the Church is not to bury it, but to make it hard again.