By Luis Lugo
“Today more than ever it is… important to reaffirm that the theory of ‘just war’… is now outdated.” With that bold statement, accentuated by the quotation marks of suspicion, paragraph 192 of Magnifica humanitas appears to sweep away nearly two thousand years of Christian teaching on this subject. If that were the case, it would be a great irony. For the Church’s teaching on just war is closely associated with St. Augustine of Hippo, the inspiration for the Order of our Augustinian Pope.
Some have interpreted the previous statement as a simple sign of the belief that this teaching is no longer useful, that it is worn out or obsolete and that, consequently, it should be safely stored somewhere in the Vatican archives. Pope Leo gives some credence to this view by invoking the legacy of his immediate predecessor.
The connection with Pope Francis is made explicit not only in the use of the word “reaffirm,” but also by a footnote reference to Fratelli tutti (258). In that encyclical, the late pontiff expressed serious doubts about the continued validity of this teaching. On another occasion he was even more emphatic, categorically stating that we can no longer speak of just wars because wars are always unjust.
If that does not express an adoption of pacifist principles, it has certainly resulted in many Church authorities adopting a kind of functional pacifism. The question is whether Pope Leo now intends, both with this encyclical and with his forceful statements on the war in Iran, to take the next step and openly endorse a pacifist stance. Although understandable, that conclusion may be a bit too hasty.
To begin with, we must carefully observe the two ellipses in the initial quotation. The first omitted statement, which I italicize here, reads: “Today more than ever, without prejudice to the right to legitimate defense in the strictest sense”. The second follows: “it is important to reaffirm that the theory of ‘just war,’ which has too often been used to justify any kind of war, is now outdated”.
The first statement clearly ratifies a classical understanding of the right to legitimate defense, which has always been a fundamental pillar of the just war tradition. This alone contradicts any attempt to give the encyclical a pacifist slant. With the second statement, the Pope rightly warns against overly broad applications of this principle. But demanding a stricter application of a principle is different from repudiating it; it is another way of affirming its validity.
The continued relevance of just war theory is assumed throughout this section of the encyclical. For example, in its vigorous condemnation of the use of force by non-state actors, including “jihadist groups, private militias, and criminal networks.” (196) This is simply an indirect way of affirming another important principle of just war, namely, that for wars to be just, they must be waged by a legitimate authority. As St. Augustine rightly noted, in determining the justice of a war, “much depends on the causes for which men undertake wars and the authority they have for doing so.”
The encyclical relies on other foundational principles of just war. That war must be a last resort, for example, which is another important consideration in determining the morality of any given war. In that sense, the encyclical clearly upholds “the principle that armed force must be used as a last resort in cases of legitimate self-defense.” (197)
Furthermore, the encyclical also affirms certain principles related to justice in the conduct of war. One of these involves maintaining the crucial distinction between combatants and non-combatants. Another is “the principle of proportionality in response to aggression.” (203)
In short, if his intention was to declare just war theory obsolete, the Pope chose a very strange way to proceed. In any case, the numerous affirmations in the encyclical of the principles of just war only serve to underscore their continued relevance in the Church’s moral reflection on the morality of war.
This is not to deny the need to update how these enduring principles of just war are applied. But that is true for all aspects of natural law, whose concrete application must always take into account, as the Catechism says, the “various conditions of life according to places, times, and circumstances.”
The encyclical appropriately expresses serious concerns about some of the new circumstances, especially the prospect of deploying autonomous weapons on the battlefield driven by AI. It also draws attention to what it calls “hybrid forms” of conflict, including cyberattacks and disinformation campaigns.
Another pressing issue, to which the encyclical only alludes indirectly, is the use of non-state actors as proxies to bring death and destruction to an enemy. Is this not aggression by other means? If so, what are the implications of this for the way we think about the legitimacy of the preventive use of military force against those who wage undeclared wars of this kind?
All these problems (and more) underscore the need for a thoughtful update of the conditions under which the principles of just war must be applied. If the theory of war is outdated, then the appropriate response is to update it, not discard it.
Some have too easily jumped to the conclusion that with this encyclical Pope Leo is guiding the Church toward the pacifist camp. But this assumes that the Church can simply set aside the demands of natural law, whose requirements underpin the principles of just war. As I have attempted to show, a careful reading of the encyclical does not support such a conclusion.
The challenge for the Church today is to update—through greater development rather than discard—its historic teaching on just war. Adopting a pacifist stance will only serve to marginalize faithful Catholics from serious discussions on a subject of transcendent importance where the moral wisdom of the Church is needed now more than ever.
About the author
Luis E. Lugo is a retired university professor and foundation executive who writes from Rockford, Michigan.