Hello, Parishioners:
The Catholic Church holds that peace is the supreme good and that war is always a tragic evil to be avoided if at all possible. Nonetheless, it recognizes that nations sometimes have both the right and duty to defend themselves and others against unjust aggression. From this sober realism, the Church’s Just War doctrine has developed, rooted in the writings of St. Augustine (cf. City of God, Book XIX) and refined by St. Thomas Aquinas (Summa Theologiae, II-II, q. 40).
According to the Catechism of the Catholic Church, four conditions must all be met for a war to be morally justified (CCC 2309):
- Just Cause: The damage inflicted by the aggressor must be lasting, grave, and certain.
- Legitimate Authority: Only governments with proper authority may declare war
(cf. Romans 13:1–4).
- Right Intention: The goal must be to secure a just and lasting peace, not vengeance or conquest.
- Last Resort: All other means of resolving conflict must have been shown to be impractical or ineffective.
Even if these criteria are met, the conduct of war must obey moral principles:
- Proportionality: The use of force must not produce evils greater than the evil to be eliminated (CCC 2309).
- Non-Combatant Immunity: Civilians must never be directly targeted. The intentional killing of the innocent is always morally wrong (CCC 2312–2313).
Modern popes have grown increasingly skeptical that modern warfare can ever meet these conditions, given the devastating power of modern weapons and the interconnectedness of nations. St. John XXIII in Pacem in Terris (1963) emphasized that nuclear war is morally unacceptable. St. John Paul II, in his 1991 Centesimus Annus (§52), warned that wars today often cause disproportionate harm.
In 2020, Pope Francis, in Fratelli Tutti (§258), calls war “a failure of politics and of humanity,” and insists it can no longer be seen as a solution because of its “destructive power” and inevitable harm to civilians.
Still, the Church does not embrace absolute pacifism. The right of self-defense remains legitimate, especially to protect the innocent (CCC 2265). Soldiers engaged in a truly defensive war are not
automatically committing sin, provided they adhere to moral norms.
Thus, the Church holds that a “just war” is theoretically possible—but extremely rare. The presumption must always be for peace, pursued through dialogue, diplomacy, and justice.
-- Fr. Augustine Joseph