Just War and the Catholic Church
The recent conflict in Iran has once again raised questions about why wars are waged and whether they can be justified. We see war-torn nations suffering, inflicted by pain that could have been avoided, yet the debate over whether a war can be just continues.
What is a “just war”?
According to the Catechism of Catholic Church 2309, in order to safeguard peace, the use of military force is morally acceptable under strict conditions. St. Thomas Aquinas clearly articulated the Just War Theory in Summa Theologiae (II-II, 40, 1) stating that for war to be just, “three things are necessary: proper authority, just cause, and right intention.” These principles outline the following conditions, all of which must be met:
- Just cause: the damage inflicted by the aggressor must be lasting, grave and certain such as invasion or mass violence
- Declared by a legitimate authority: only a sovereign government may declare war; not individuals or private groups
- Last resort: all other attempts to restore peace must have been exhausted
- Right intention: the goal is to restore peace and justice instead of revenge, power or economic gains
- Probability of success: realistic chance of achieving the goal and it is not a hopeless effort
- Proportionality: the damage caused by war should not exceed the damage of avoiding war
The above known as the Just War theory traces its roots to the war ethics of St Augustine of Hippo in the 4th century who argued that the purpose of war should ultimately be to restore peace.
“We do not seek peace in order to be at war, but we go to war that we may have peace.“— St Augustine
Essentially, it is to protect innocent lives. Augustine sought to reconcile Christian pacifism with the realities of a fallen world.
“The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.”— G.K. Chesterton
The above conditions are reflected in the international laws of jus ad bellum (the right to go to war) and jus in bello (justice in war). For a war to be just, it must fulfill these principles—both the proper reasons for going to war and the just conduct of war, especially in the treatment of combatants and civilians, and in maintaining proportionality (jus in bello).
What is the stand of the Church on war?
The Catechism of the Catholic Church (2307–2308) teaches us that we should work to avoid war and always strive to safeguard peace.
“Because of the evils and injustices that accompany all war, the Church insistently urges everyone to prayer and action so that the divine Goodness may free us from the ancient bondage of war. All citizens and all governments are obliged to work for the avoidance of war” (CCC 2307–8).
Pope Paul VI
Twenty years after World War II, having witnessed the devastation caused by atomic bombs and the destruction of countless lives and cities, and amid the rising tensions of the Cold War and the nuclear age, Pope Paul VI made a heartfelt plea at the United Nations on 4 October 1965: ‘No more war, war never again.’”
Pope John Paul II
No to war! War is always a defeat for humanity.
In 2003, Pope John Paul II called for peace, condemning the Iraq War and urging an end to hostilities. He emphasized “international law, honest dialogue, solidarity between States, and the noble exercise of diplomacy,” insisting that even preventive war is unjust.
Pope Benedict XVI
Pope Benedict XVI reinforced this position, noting that “the concept of preventive war does not appear in the Catechism of the Catholic Church,” and that the Vatican’s stance of “No to War” explicitly includes preventive wars, because they are not just.
Pope Francis
“War itself is a crime against humanity. People need peace. The world needs peace.”
In a 2022 interview, Pope Francis acknowledged that a “war may be just“, but emphasized the need to “rethink the way the concept is used nowadays.“
Pope Leo XIV
“Every war is truly a wound inflicted upon the entire human family; it leaves in its wake death, devastation and a trail of pain that marks generations.”
In the wake of the Iran conflict, Pope Leo XIV made a heartfelt appeal to all parties involved “to assume the moral responsibility of halting the spiral of violence before it becomes an unbridgeable chasm.”
Final Reflection
Having considered the Church’s teaching on safeguarding peace and the repeated pleas to end wars, we are invited to reflect on the wise words of John F. Kennedy when he addressed the United Nations in 1961: “Mankind must put an end to war, or war will put an end to mankind.” He urged the world leaders to contemplate the real threat of destruction, describing it as “under a nuclear sword of Damocles, hanging by the slenderest of threads, capable of being cut at any moment by accident or miscalculation or by madness.” His words seem even more of a reality today than they did in 1961, as global instability looms.
In the face of such dangers, the Church consistently reminds us to rely on the spiritual weapons of—prayer, fasting and almsgiving—as powerful means to pray for peace and cultivate a culture of dialogue and compassion instead of conflict. (SR)