Does the Catholic Church still believe in the doctrine of just war? Last week, Pope Francis told Patriarch Kirill of the Russian Orthodox Church, “At one time we also spoke in our churches of holy war or just war. Today we cannot speak like that.” The pope’s criticism of the just war tradition was not a passing comment. It reflects a longstanding view that Francis elaborated in a 2015 speech and a 2020 encyclical.

The pope’s comment last week was part of his criticism of Kirill’s inexcusable misuse of his authority to support Russia’s invasion of Ukraine. Kirill is a perfect example of what happens when a church gets too close to the state. In supporting Vladimir Putin’s war, he has allowed his moral authority to be coopted by an authoritarian to be used as a fig leaf for a murderous war of conquest, cheapening and undermining the theological language Christians have long used to think about justice and war.

But the pope, in pushing back against Kirill, has mistaken his target, shot himself in the foot, and revealed his own evident misunderstanding of the just war tradition. Instead of criticizing the just war tradition, he should be using the just war tradition.

The pope’s criticism of the patriarch was foreshadowed in his 2020 encyclical, Fratelli Tutti (see Joe Capizzi’s commentary on it for Providence here and his talk with Mark Tooley about it here). The pope writes, “War can easily be chosen by invoking all sorts of allegedly humanitarian, defensive or precautionary excuses, and even resorting to the manipulation of information.” He probably intended that as a veiled criticism of the 2003 US invasion of Iraq, but it applies even more accurately to Russia’s invasion of Ukraine—for which Putin invented a humanitarian pretext of protecting ethnic Russians from a non-existent genocide by the Ukrainian government. The pope rightly notes, “In recent decades, every single war has been ostensibly ‘justified’… Yet it is easy to fall into an overly broad interpretation of this potential right.”

The pope is right that aggressors and their shills too easily manipulate the language of just war to claim every military adventure is justified. But he goes further than that. “We can no longer think of war as a solution, because its risks will probably always be greater than its supposed benefits,” he writes. “In view of this, it is very difficult nowadays to invoke the rational criteria elaborated in earlier centuries to speak of the possibility of a ‘just war.’” 

With this and similar comments, the pope seems to call into question the entire historic Christian tradition of just war thinking. He claims, “Every war leaves our world worse than it was before. War is a failure of politics and of humanity, a shameful capitulation, a stinging defeat before the forces of evil,” and quotes Pope John XXIII that “it no longer makes sense to maintain that war is a fit instrument with which to repair the violation of justice.”

Note that the pope’s critique of just war thinking depends on some empirical claims. He claims that war’s “risks will probably always be greater than its supposed benefits,” and that “every war leaves our world worse than it was before.” This is similar to the US Catholic Bishops’ claim in their 1983 pastoral letter that the technology of modern warfare makes it virtually impossible to wage a just war with proper discrimination and proportionality. They quote Pope John Paul II to the effect that “today, the scale and the horror of modern warfare—whether nuclear or not—makes it totally unacceptable as a means of settling differences between nations.” These comments are tantamount to de facto pacifism and an explicit rejection of just war thinking.

But what if these claims are not true? Pope Francis’ claim that “every war leaves our world worse than it was before,” seems obviously wrong, or at least wrongly framed. The question is not whether war leaves the world worse off than it was before, but whether fighting a war makes the world worse compared to how it would otherwise be. When faced with the Nazi conquest of Europe, we no longer had the choice to return to the world as it was before, but we could still choose to fight for a world better than the one the Nazis envisioned. We clearly made the right choice.

Francis’ view implies a utopian politics in which we could always choose the best rather than the real world in which we often must choose the lesser of two evils. His utopianism is also evident in his claim that “the Charter of the United Nations, when observed and applied with transparency and sincerity, is an obligatory reference point of justice and a channel of peace.” The idea that the UN Charter is an “obligatory reference point of justice” is appalling; this is the same charter that gives equal voice to totalitarian regimes as democratic ones and that allows human rights abusers to sit on its human rights council. As for the notion that the Charter is a channel of peace—world history since 1945 suggests otherwise.

Similarly, the other claims about modern war are simply uninformed about the actual nature of most wars in the world today. John XXIII, John Paul II, and the US Catholic Bishops were responding to World War II and the Cold War’s nuclear arms race. Those are not universal templates of how all, or even most, actual wars play out. World War II was, in fact, the most extreme, catastrophic, and unusual war in all history. We should not develop a just war doctrine solely in response to those wars’ specific and unique characteristics.

Most wars are small, and none have included nuclear weapons since 1945. The true weapon of mass destruction is the AK-47 assault rifle, which—as the standard infantrymen’s weapon of choice in virtually every war, revolt, and insurgency around the world over the past 75 years—has killed far more human beings than nuclear weapons ever have. Most “modern wars” involve small units wielding small arms shooting and killing each other over relatively small areas (sometimes with larger and heavier conventional fighting involving tanks and bombers preceding or occasionally supplementing the small-unit fight).

That means the conditions of most “modern wars” do not look drastically different from wars preceding the twentieth century. Traditional just war doctrine is still relevant. The one distinguishing characteristic of many “modern wars” is that they often take place in civilian areas and kill a lot of noncombatants—in which case, again, the just war criteria of discrimination is absolutely relevant.

This points to the incoherence of Pope Francis’ comments about just war. Even as he criticized just war language as part of his criticism of Patriarch Kirill, he affirmed the Ukrainians’ right to defend themselves. As virtually everyone knows, that is exactly what the just war tradition affirms. The just war tradition affirms that it is just for the Ukrainians to wage war in defense of their lives, their independence, and their freedom. Francis criticizes the language of the just war tradition while affirming its content and conclusions, seemingly unaware of the obvious contradiction.

Pope Francis’ heart is in the right place. He rightly notes that “war is the negation of all rights and a dramatic assault on the environment. If we want true integral human development for all, we must work tirelessly to avoid war between nations and peoples.” That, at least, we can agree on. The pope should recognize that the just war tradition is an ally, not enemy, of that vision.