In Pope Leo’s first encyclical, he makes several interventions on war, violence, and injustice, to question the Church’s teaching of just war theory in modern warfare.
What is the just war theory?
The just war theory was largely created through the writings of saints Augustine and Thomas Aquinas to determine whether warfare could possibly be morally justified, but under strict conditions. These conditions traditionally include having a just cause, only using force as a last resort, having a reasonable chance of success and protecting civilians.
“The use of force, violence and weapons reflects a relational poverty that always has disastrous consequences for civilian populations.”
Pope Leo has challenged the theory, writing that it has become increasingly insufficient, and is now outdated in a world increasingly shaped by advanced weaponry and artificial intelligence.
Additional criteria have been introduced by Pope Leo, who has stated that they should also be considered before warfare. These include:
- Ensuring a clear chain of responsibility when automated technologies are used in combat
- Establishing a moral timeframe for making judgments in an era when AI can accelerate military decisions
- Safeguarding civilians
In his encyclical, Pope Leo is not dismissing the right to legitimate self-defence in warfare but instead challenges us to consider whether the use of force can meet the strict moral demands required to justify it in modern warfare. He emphasises that dialogue, diplomacy and forgiveness are far more effective ways of resolving conflict and protecting human life.
“Humanity possesses far more effective and capable tools for promoting human life and resolving conflicts, such as dialogue, diplomacy and forgiveness.”