While this year marks the sixtieth anniversary of Pope John XXIII’s encyclical Pacem in terris, which was issued on April 11, 1963, the past fifteen months have served as a reminder of the continuing threat and reality of bellum in terris. Indeed, Pope Francis has remarked more than once that “a third world war fought piecemeal” is underway not only in Ukraine, but also in Syria, Myanmar, and “everywhere in Africa.” As the pope has also noted, the people of Ukraine are being “martyred” by Russian aggression, and the consequences of this war are affecting other people, especially the poor and vulnerable, in places such as Africa. Finally, the risk of escalation from conventional to nuclear war—with repercussions for the whole world—has weighed heavily in statements by Pope Francis and others.

At the same time, Pope Francis has been criticized for suggesting that NATO’s expansion was partly to blame for Russia’s invasion of Ukraine, and for failing to denounce more explicitly Vladimir Putin and the Russian forces. But in his Angelus on March 6, 2022, the pope did say that what is happening is not merely a “military operation [Putin’s euphemism], but a war that sows death, destruction, and misery.” Likewise, a week later Francis referred to the “unacceptable armed aggression,” obviously with Russia in mind. Yet he added that “those who support violence profane” God’s name, since “God is only the God of peace.” Did this last judgment refer only to the forces of the aggressor or also to Ukrainian men and women who have felt compelled to take up arms in defense of their country and fellow citizens? Again, after the massacre in Bucha, Pope Francis deplored the “ever-more horrendous acts of cruelty done against civilians, unarmed women and children, whose blood cries out to heaven and implores, ‘End this war. Silence the weapons. Stop sowing death and destruction.’” While clearly condemning Russia’s indiscriminate violence against Ukrainian civilians, the pope’s plea “to silence the weapons” sounded to some as if it could be directed at both countries. A year later, at his Sunday Angelus on March 19, 2023, Francis prayed, “Let us not forget to pray for the battered Ukrainian people, who continue to suffer due to war crimes,” but he went on to pray for “the mothers of the Ukrainian and Russian soldiers who have fallen during the war”—thereby, as one report put it, “continuing the path begun by Vatican diplomacy since the conflict began in February 2022, trying to stay equidistant between Russia and Ukraine.”

Massimo Faggioli has argued in these pages that “Russia’s war in Ukraine, where there is clearly an aggressor and an attacked,” tests the Vatican’s position of permanent neutrality in international relations, a policy that risks “drawing moral equivalence between Russia and Ukraine.” I would add that this war also tests the recent narrowing of the Catholic ethic of war and peace to nonviolence. On several occasions—including in a recent call for people to pray during the month of April for a culture of nonviolence and peace—Pope Francis has claimed that “any war, any armed confrontation, always ends in defeat for all.” Accordingly, he implores us to reject violence: “Let us make nonviolence a guide for our actions, both in daily life and in international relations.”

This emphasis on nonviolence appeared in Francis’s 2017 World Day of Peace message, “Nonviolence: A Style of Politics for Peace,” which he wrote at the request of the Catholic Nonviolence Initiative, a project of Pax Christi International. In April of the prior year, Pax Christi International and the Pontifical Council for Justice and Peace sponsored a Nonviolence and Just Peace Conference that issued an “Appeal to the Catholic Church to Re-Commit to the Centrality of Gospel Nonviolence.” While urging the Church to promote education and training in active nonviolence, the Appeal asserted “that there is no ‘just war’” and that “often the ‘just war theory’ has been used to endorse rather than prevent or limit war.” Although “often” is not the same as “always,” the Appeal went on to recommend that the Church should “no longer use or teach ‘just war theory.’” Pope Francis has appeared sympathetic to this recommendation, writing in his 2020 encyclical Fratelli tutti that “it is very difficult nowadays to invoke the rational criteria elaborated in earlier centuries to speak of the possibility of a ‘just war.’ Never again war!”

David DeCosse observes that an increasing “Catholic skepticism about the moral justification of war at all” has developed in recent years. According to Lisa Sowle Cahill, proponents of this move toward “a pacifist direction,” though still a minority, have “considerable” sway and see “all military action as a moral failure.” This view is reflected in the prayers and remarks of Pope Francis, as well as in op-ed pieces by some Catholic theologians—most notably Eli McCarthy, one of the more influential promoters of nonviolence, just peace, and the rejection of just-war theory.

I have often wondered, though, how a Ukrainian soldier or civilian who took up arms to defend his or her fellow citizens must feel whenever the pope and others have emphasized nonviolence and condemned the use of armed force. If I were in such a person’s shoes, would I feel like “a moral failure” because I had used armed force to repel an invasion? While I have never found myself in such dire circumstances, when I was an ROTC student and also a law-enforcement officer in the 1980s, I wrestled with such questions—especially in the latter capacity, where I sometimes had to use force to defend myself or others from violent attack. Although I was moved by the example of Gandhi and attracted to Christian pacifism—and even studied under two of the most influential critics of just-war theory, Stanley Hauerwas and John Howard Yoder—I continue to think that using armed force is sometimes the morally right thing to do. It may not be good, but it is right—as long as it is just.

Eli McCarthy insists that Pope Francis is not “condemning or judging people in very difficult situations, like some [some?] Ukrainians who choose to take up arms in violent defense of their country,” and that the pope “affirms and admires their willingness to take a high-risk stand against injustice rather than to be passive.” Still, McCarthy himself highlights and endorses only examples of nonviolent methods that some Ukrainians are using to resist Russian forces. After all, in his view, what the pope has in mind “is also not about justifying methods of war and enabling the violent dynamic to perpetuate and spread.” I worry McCarthy’s words about those “who choose to take up arms” come across as condescending. It isn’t enough to say that their willingness to actively resist injustice is commendable; their use of armed force in that resistance is also morally justified. I suspect that if they could have chosen some other method of resistance, most Ukrainians would have done so, but Russian bullets were already flying, Russian tanks already rolling in, Russian missiles already striking not only Ukrainian military targets but also civilian apartment complexes, schools, and hospitals. As for McCarthy’s concern about “justifying methods of war,” in the Catholic moral tradition, just-war theory rather aims to limit and constrain both when war is justified (jus ad bellum) and how it is conducted (jus in bello). In recent years, this tradition has also yielded criteria and practices for jus post bellum—justice after war—so as to put an end to “the violent dynamic” about which McCarthy is rightly concerned.

As DeCosse observes, “In the face of overwhelming odds, the Ukrainians fought back,” a feat that leads him to ask, “What are the implications of their decision to engage in a war of self-defense for the current debate within Catholicism over the rejection of just war theory in favor of Christian nonviolence?” This war has forced Catholic theologians and ethicists to ask whether some of us, including perhaps Pope Francis, have acted prematurely in relegating just-war theory to the margins or even supplanting it with pacifism. I say “perhaps” because, contrary to McCarthy’s interpretation of the pope’s position, over time the pope has come to acknowledge the moral legitimacy of the Ukrainians’ armed resistance. “To defend oneself is not only licit,” the pope said in September, “it is also an expression of love toward one’s homeland.” In a letter addressed to Ukrainian young adults, Francis wrote that “to courageously defend your homeland, you had to put your hands to weapons instead of the dreams you had cultivated for the future.” And, in his recent call for prayer in April, while urging the world to “develop a culture of peace,” the pope added, “remember that, even in cases of self-defense, peace is the ultimate goal.”

Admittedly, Francis has never said that the Ukrainians are fighting a “just war” or that the Russians are conducting an “unjust war.” But the traditional moral criteria for just war—just cause, right intent, proportionality, discrimination, etc.—are the bases for many of Pope Francis’s remarks about legitimate defense versus aggression and indiscriminate slaughter. Even if we don’t always name them as such, the Catechism reminds us that “these are the traditional elements enumerated in what is called the ‘just war’ doctrine” (2309).

Massimo Faggioli has suggested that the war in Ukraine might prove to be “a turning point” in Catholic teaching about war and peace. Michael Sean Winters writes that “the most significant intellectual development in the life of the church this year was the emphatic reinstatement of just war theory as the principal Catholic moral approach to violence.” Perhaps “reinstatement” is an overstatement, for just-war theory was never really set aside, not even by Pope Francis, even if he no longer uses the term.

Of course, there’s more than one version of just-war thinking within the tradition. Cahill and others identify two basic approaches to just-war theory: one that offers “energetic defenses of war” and another that advocates a more “restrictive” or “stringent” use of just-war reasoning and principles. In my view, if there was any real debate in Catholic circles on the ethics of war and peace in recent decades, it was between these two approaches, not between just-war theory and pacifism—that is, not until the 2016 Appeal’s condemnation of just-war theory. Since Russia invaded Ukraine in February 2022, many articles, blogs, and op-eds by Catholics and others representing the two broad approaches to just-war thinking have offered a moral evaluation of the fighting by both sides, as well as of the provision of support and arms by their allies.

Representing the less stringent camp, George Weigel maintains that “the just-war tradition is the normative way of thinking about the challenges of war and peace within a classic Catholic understanding of international relations,” even as he acknowledges that this tradition includes a “peace imperative,”—a “jus ad pacem” commitment for “conducting a just war in such a way that a just peace is its result.” While acknowledging the complexities of just-war analysis, Weigel holds that Russia’s “war on Ukraine is clearly” and “unambiguously” unjustified as well as unjustly conducted, whereas Ukraine’s “is a war of legitimate self-defense, which…has been conducted proportionately and discriminately.” Similar analyses have been offered by J. Daryl Charles, Anglican theologian Nigel Biggar, and others associated with the less restrictive approach to just war.

From the more stringent camp, Gerald J. Beyer worries that his “fellow citizens and colleagues in the academy in the U.S. do not grasp the reasons for the war and its monumental stakes.” Beyer warns that “this war is about annihilating a country and its people and continuing Russian expansionism if left unchecked.” He emphasizes that he is not “hawkish,” much less a “warmonger”: he opposed the U.S. wars in Afghanistan and Iraq. Indeed, Beyer says he “abhors war and believes that all other reasonable means should be exhausted before the use of lethal force is undertaken,” but he is “convinced there are times—albeit rare—when the evil is so great that no measure other than force will prevent grave atrocities on a massive scale.” While he supports the active nonviolence, civil resistance, and just peacemaking practices advocated by the Catholic Nonviolence Initiative and others, Beyer believes that these “alone will not stop the Russian juggernaut.” Other Catholic theologians and ethicists—including Anna Floerke Scheid, David DeCosse, Ramón Luzárraga, Ashley Beck, and myself—take the same view.

Cardinal Robert W. McElroy spoke on “Our New Moment: Renewing Catholic Teaching on War and Peace” at the University of Notre Dame on March 1, 2023. Like Faggioli, McElroy believes the war in Ukraine is a turning point. The Church, he argues, still needs to prioritize nonviolence, but we also need “a deep renewal, restructuring and expansion of the Catholic teaching on the legitimacy of war in extremis.” McElroy recognizes the flaws of just-war theory and the risks of its misapplication, but he thinks the “ethical tools” are present “to be forged into a larger ethic of war” for times such as this one. He laments the lack of an “ethics of war termination,” though this question has actually received significant attention from just-war theorists in recent years.

Both McElroy and Faggioli mention the U.S. bishops’ 1983 pastoral letter The Challenge of Peace: God’s Promise and Our Response, which sought to “help Catholics form their consciences and to contribute to the public policy debate about the morality of war.” I know it helped me as I wrestled with these questions at the time. When the United States went to war against Iraq twenty years ago, Drew Christiansen, SJ, asked “Whither the ‘just war’?” and replied that Catholic teaching, as reflected in documents like The Challenge of Peace, has “evolved as a composite of nonviolent and just-war elements.” In his recent book, Preventing Unjust War, Roger Bergman argues that The Challenge of Peace, which “takes nonviolence seriously” and “teaches a strict interpretation of the just-war tradition,” offers a “richness” that is “missing from the Appeal” of 2016. He thinks the bishops “got it right”: “We should simultaneously develop strategies of nonviolence and hold to a strict understanding of when war can be justified, and when it cannot—but we should not jettison the tradition until it is genuinely obsolete.”

I agree. I recommend a return to the bishops’ insistence that proponents of nonviolence and just-war theorists can work together in a complementary way. Indeed, Pope Francis’s 2017 message on nonviolence makes the same point: “Peacebuilding through active nonviolence is the natural and necessary complement to the Church’s continuing efforts to limit the use of force by the application of moral norms.” Accordingly, in his recent book on Catholic social teaching, the pacifist theologian William O’Neill, SJ, encourages both sides of the debate to “not condemn” but rather to “learn each from the other” and work together. Such a joint effort could eventually produce the “larger ethic” Cardinal McElroy hopes for—what I would call an ethic of legitimate defense, both armed and unarmed. Perhaps the Ukraine-Russia war will further stimulate collaboration among Catholic theologians and ethicists. Maybe it will even lead to a new synthesis, one that will help guide Catholics and others to defend and achieve a just and integral peace. We can hope.

This article appeared as one part of an exchange about the ethics of war in Commonweal’s May 2023 issue. You can read the other part of the exchange, by William T. Cavanaugh, here.