Bellum Justum (Just War)

Bellum Justum, or Just War theory, is a set of ethical principles that determine when it is morally acceptable to go to war and how to conduct oneself during conflict. It emphasizes that war should only be fought for just causes (like self-defense or protecting innocents), with proper authority, and as a last resort. Additionally, it requires proportionality—ensuring the violence used is balanced with the goal—and protection of non-combatants. The theory seeks to balance justice and morality in warfare, aiming to prevent unnecessary suffering while addressing serious grievances.