Four days after the U.S. military invasion of Iraq, Drew Christiansen, S.J., asked in the pages of America: “Whither the ‘Just War’?” (March 24, 2003). Now that President Donald Trump, after amassing warships, aircraft and troops in the Caribbean in recent months, has carried out military strikes in Venezuela and captured President Nicolás Maduro, I think it worthwhile to revisit Father Christiansen’s article, written before he served as editor in chief of America from 2005 to 2012, for insights about the continuing relevance of just war theory—especially since it is withering away with the Trump administration’s “Rambo” militarism, as well as its apparent fall from favor in Catholic magisterial teaching. 

In 2002, the U.S. ambassador to the Holy See, Jim Nicholson, had invited Michael Novak of the American Enterprise Institute to fly to Rome in an attempt to persuade the Vatican that a “preventive war” against Iraq would be morally justified, based on emerging threats and terrorism. Mr. Novak was unsuccessful in what Father Christensen called “a bold move.” The Vatican, along with the U.S. Catholic bishops and many moral theologians (including myself), continued to use just war principles to raise serious questions about the looming war. 

According to Father Christiansen, this disagreement reflected a deeper internal dispute about just war theory itself, and how it is understood. He noted that, beginning with the Second Vatican Council’s “Gaudium et Spes,” Catholic teaching on war and peace had been shifting from just war as its only approach toward “a composite of nonviolent and just war elements.” Both the U.S. bishops’ 1983 pastoral letter “The Challenge of Peace” and their 1993 statement “The Harvest of Justice Is Sown in Peace” held that proponents of nonviolence and of just war theory must share a “presumption” for peace and against war.

It was this hybrid position that just war thinkers disagreed about at the time. On the one hand, there were “mainline” just war theorists who favorably regarded this development in magisterial teaching and who supported more attention to nonviolence in order to make sure just war is truly a last resort. But there were also critics who were wary of pacifism, and who countered that the supposed presumption against armed force was, as Father Christiansen wrote, “an innovation that impedes the restoration of justice.” Father Christiansen called the latter group “moralists of the permissive school” because of “their willingness to justify most government policies” based on the principle of just cause.

For Father Christiansen, while just cause is necessary for military action, it is insufficient. The other criteria used to determine ahead of time if a war is just (jus ad bellum)—legitimate authority, right intention, last resort, probability of success and proportionality—also “must be met before a war is judged to be moral.” Moreover, Father Christiansen observed that the Bush administration’s National Security Strategy report in 2002 asserted “U.S. dominance over all potential rivals,” which he added was “a position directly at odds with the Augustinian notion of right intention, which excludes the libido dominandi, the lust for power.”

It was this objective of military domination that fueled the Bush administration’s expansion of the principle of just cause to include preventive war, which Father Christiansen pointed out was actually “a dangerous innovation” in Catholic just war thinking and teaching. Although pre-emptive strikes may be permissible in the face of a grave and imminent threat, preventive wars in anticipation of possible threats further in the future are not legitimate. According to Father Christiansen, the Bush administration juxtaposed pre-emptive with preventive, a move that permissive just war proponents like Novak supported and stricter just war adherents opposed.

Is there such a thing as a ‘just war’?

In addition to providing this update on the thinking about just war among its theorists, Father Christiansen pointed out to readers in “Whither the ‘Just War’?” that some Catholics were suggesting that just war no longer has any place in church teaching. He mentioned Archbishop Renato Martino, at the time president of the Pontifical Council for Justice and Peace, who suggested that just war should go the way of the death penalty, since modern societies have other means to protect themselves and “to avoid war.” Father Christiansen noted that the archbishop was “not the first Vatican voice to urge the church to discard the Just War as outmoded.”

In Father Christiansen’s view, however, such a position “would have serious implications,” including that the ability for the church to use just war criteria “to prevent and limit war would be greatly reduced, as would its ability to provide moral commentary on the formation of military policy and the actual conduct of war.” 

He also mentioned Joaquín Navarro-Valls, the head of the Vatican Press Office at the time, who said that “the pope is not a pacifist.” Accordingly, Father Christiansen called for “authoritative clarification” and “clearer articulation” about how nonviolence, just war and peacemaking might fit “into a coherent teaching on peace and war.”

Just war from Bush to Biden

Recently, the Catholic ethicist Kenneth R. Himes, O.F.M., noted in Commonweal magazine how just war’s jus in bello principles of discrimination (also known as noncombatant immunity) and proportionality were taken more seriously by the Pentagon after military experts realized from the Bush administration’s “war on terror” that high numbers of civilian casualties turned local populations against the United States and boosted recruiting efforts by terrorist groups. In his Nobel Prize acceptance speech in 2009, Barack Obama expressed his respect for the just war tradition “to regulate the destructive power of war,” even though he admitted that it has been “rarely observed.” Under his administration, in 2015, the Department of Defense’s Law of War Manual sought to minimize civilian casualties. Such a commitment allowed just war ethicists such as Mark Allman and myself to critique drone strikes Mr. Obama ordered that were indiscriminate and disproportionate.

During Mr. Trump’s first term, Georgetown law professor Rosa Brooks wrote that “in contrast to Bush, Trump makes no secret of his disdain for the laws of war.” In her judgment, “Bush at least tried to cloak his administration’s use of torture in legal sophistry, a backhanded testament to the strength of the norms his aides sought to circumvent.” 

President Biden’s administration attempted to re-enforce the efforts made during President Obama’s two terms to limit and reduce civilian casualties. In 2022, Secretary of Defense Lloyd Austin called for the creation of the Civilian Harm Mitigation and Response Action Plan (CHMR-AP), which was released eight months later and stated at the outset: “[t]he protection of civilians is a strategic priority as well as a moral imperative.” This stated commitment permitted just war theorists to criticize U.S. military actions and policies, such as providing Ukraine with indiscriminate cluster munitions. 

Not just war, just war: The Rambo position

We can no longer count on such a commitment during Mr. Trump’s second term, with its use of gunboat diplomacy to enforce the president’s “Donroe corollary” to the Monroe Doctrine. In his new book Killing Machines: Trump, the Law of War, and the Future of Military Impunity, Thomas Gift argues “that Trump is unique among U.S. presidents in the extent of his willingness to discard the law of war.” His defense secretary, Pete Hegseth, has fired top Army and Air Force lawyers, and removed staff assigned to implement CHMR-AP. 

Mr. Hegseth’s actions, according to Father Himes, “reflect an agenda he held prior to his role as a member of the Trump cabinet”—namely, inculcating “a ‘warrior ethos’ in the military.” Indeed, Mr. Hegseth told military leaders in September: “We fight to win. We unleash overwhelming and punishing violence on the enemy. We don’t fight with stupid rules of engagement. We untie the hands of our warfighters to intimidate, demoralize, hunt and kill the enemies of our country.”

The “warrior ethos” is also evident in the Trump administration’s 2025 National Security Strategy document. Although purporting to be “muscular without being ‘hawkish,’ and restrained without being ‘dovish,’” it has extended the “war on terror” to include drug cartels and gangs, as well as “the use of lethal force to replace the failed law enforcement-only strategy of the last several decades.” 

Accordingly, Mr. Hegseth posted on X: 

Narco-terrorists are enemies of the United States—actively bringing death to our shores. We will stop at nothing to defend our homeland and our citizens. We will track them, kill them and dismantle their networks throughout our hemisphere—at the times and places of our choosing.

We witnessed this approach beginning in September with deadly strikes on small civilian boats in the Caribbean.

This “warrior ethos” manifests even more the libido dominandi about which Father Christiansen warned in 2003. As the Catholic ethicist Matthew Shadle recently has written, for Augustine, the libido dominandi is the foundation of an unjust political order that initiates unjust wars. Given its emphasis on masculinity and virility, the “warrior ethos” reminds me of what one of my teachers, John Howard Yoder, called “the Rambo position,” with its excessive violence in which “neither other parties in the conflict nor any principles above the fray have any moral standing.”

Not Just War, but holy war

The “warrior ethos” promulgated by Mr. Hegseth, moreover, converges with the “holy war” logic that the historian Roland Bainton highlighted in his 1960 classic Christian Attitudes Toward War and Peace. Bainton included the medieval Crusades among his examples of this holy war attitude. In contrast to just war reasoning, the holy war mentality tends to ignore criteria such as probable success and last resort, as well as noncombatant immunity. Accordingly, in “The Challenge of Peace,” the U.S. bishops admonished against “a crusade mentality” whereby a nation acts as if it has “absolute justice” on its side and is no longer compelled “to restrain the use of force even in a ‘justified’ conflict.” 

Similarly, in his Nobel Prize speech, Mr. Obama warned “that no holy war can ever be a just war. For if you truly believe that you are carrying out divine will, then there is no need for restraint—no need to spare the pregnant mother, or the medic, or the Red Cross worker, or even a person of one’s own faith.” 

Yet the holy war attitude is exactly what Mr. Hegseth openly and proudly promotes, as evident in his 2020 book American Crusade and even in his tattoos, including the phrase “Deus Vult” (“God Wills It”), which he has said is the “battle cry” of the Crusades. It also surfaced in the Signal chat message scandal earlier in 2025. As the Catholic political theorist David Carroll Cochran noted, “Those in the [first] chat expressed no concern about dead civilians.” Some of them, Mr. Cochran added, “even invoked their faith during the attacks on Yemenis.” Mr. Hegseth wrote, “Godspeed to our Warriors,” and Vice President JD Vance followed with “I will say a prayer for victory.” This holy war mentality may also be reflected in the Trump administration’s strikes against Islamic militants in Nigeria, justified as a means of protecting Christians, as well as in Pentagon videos reflecting Mr. Hegseth’s zeal for Christian nationalism.

Just war ‘unwithered’ for an integral peace

I fear, therefore, we are now witnessing the withering of just war. Unfortunately, this is happening when just war theory has also apparently withered in Catholic thought and teaching. For example, in April 2016, a gathering of Catholic activists and scholars sponsored by the Pontifical Council on Justice and Peace and Pax Christi International issued an “Appeal to the Catholic Church to Re-Commit to the Centrality of Gospel Nonviolence,” which exhorted the church “no longer to use or teach” just war theory, and rather to shift to a “just peace” approach with “nonviolent practices and strategies.” The statement also called on Pope Francis to issue an encyclical on nonviolence and “just peace.”

Although such an encyclical never appeared, Francis’ 2017 World Day of Peace message promoted nonviolence as an effective “style of politics for peace” for individual, social and international relationships. His 2020 encyclical “Fratelli Tutti” raised questions about the honest and rigorous application of just war principles today, leading Francis to write that “it is very difficult nowadays to invoke the rational criteria elaborated in earlier centuries to speak of the possibility of a ‘just war’.” Yet, the pope still acknowledged that the Catechism “speaks of the possibility of legitimate defense by means of military force, which involves demonstrating that certain ‘rigorous conditions of moral legitimacy’ have been met.” And as the Catechism notes, these moral norms “are the traditional elements enumerated in what is called the ‘just war’ doctrine.”

Even in his 2017 peace message, Francis suggested, much like the U.S. bishops did in 1983 with “The Challenge of Peace,” that “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” (emphasis added). In their 1983 pastoral letter, the U.S. bishops also refer to “just war” as a “limited war” doctrine, providing the moral norms that I think Francis refers to.

Still, there remains Father Christiansen’s call for further “authoritative clarification” and “clearer articulation” of a more “coherent teaching on peace and war.” Instead of an encyclical on nonviolence and just peace, I think we need to build on the “hybrid Catholic position” that Father Christiansen highlighted.

During their visit to Hiroshima and Nagasaki this past August, Cardinals Robert McElroy and Blase Cupich similarly called for “a more holistic approach, an integral one” in which “priority should be given to nonviolence…with just war theory…taking a more secondary role.” Yet, thus far, Pope Leo XIV has referred only to nonviolence in his statements. In his 2026 World Day of Peace message, “Peace be with you all: Towards an ‘unarmed and disarming’ peace,” Leo notes that John XXIII was the first pope to advocate “integral disarmament.” To this I would add that Pius XII urged the world—in the midst of the Second World War—for an “integral peace.” 

I suggest integral peace as a more positive and constructive way of naming the coherent, holistic, and hybrid approach that Father Christiansen, and now Cardinals McElroy and Cupich, have called for. I hope that as an Augustinian, Pope Leo will be receptive. Rather than no longer teaching or using just war theory, we need it now more than ever. As Mr. Yoder, a pacifist, counseled, nonviolence advocates and just war proponents should stop attacking each other and instead “spend more energy…[on] their responsibility to challenge the realists, crusaders, and Rambos on their ‘right’ who in fact are shooting up the world.”

Tobias Winright is a professor of moral theology at St. Patrick’s Pontifical University, Maynooth, Ireland, and an associate member of Las Casas Institute for Social Justice, Blackfriars Hall, Oxford University. Among his books are Serve and Protect: Selected Essays on Just Policing (2020) and the T&T Clark Handbook of Christian Ethics (2021).