Just War Doctrine
“Let those who have the power to unleash wars choose peace! Not a peace imposed by force, but through dialogue! Not with the desire to dominate others, but to encounter them!"
Pope Leo XIV
Urbi et Orbi, Easter 2026
The Catholic Church has developed a longstanding moral tradition concerning war and peace known as Just War Doctrine. Recognizing the reality of conflict in a world marked by injustice, this tradition begins with a strong presumption against the use of force. War is understood as a grave moral matter that must never be entered lightly. The just-war tradition, therefore, seeks both to define the limited circumstances under which force may be morally justified and to strictly regulate its use.
According to the Catechism of the Catholic Church, no. 2309:
The strict conditions for legitimate defense by military force require rigorous consideration. The gravity of such a decision makes it subject to rigorous conditions of moral legitimacy. At one and the same time:
- The damage inflicted by the aggressor on the nation or community of nations must be lasting, grave, and certain;
- All other means of putting an end to it must have been shown to be impractical or ineffective;
- There must be serious prospects of success;
- The use of arms must not produce evils and disorders graver than the evil to be eliminated. the power of modem means of destruction weighs very heavily in evaluating this condition.
Just War Resources
The USCCB has created new resources for understanding and sharing the Just War Doctrine.
Pacem in Terris
Pope St. John XXIII's 1963 encyclical Pacem in Terris offered a prophetic vision for the way the world could be if we worked together for the common good and human flourishing. The Holy Father wrote extensively about war and peace, stating that war is not an instrument to achieve justice and peace.
USCCB Pastoral Statements on War and Peace
The U.S. bishops have issued several pastoral statements on the topics of war and peace.
