Just War – Set of rules for fighting a war in a way believed to be justified and acceptable to God

To remember the meaning of Just War, use the following mnemonic:

Just allow this war (just war) as we believe it's justified and acceptable to God.

The rules of war (international agreements, Geneva convention, etc) should not be confused with whether a war is justified and acceptable to God. Religious fervour has resulted in many very unjust wars, which are still viewed by some as being justified in the eyes of God. This applies equally to Christianity in the Middle Ages, when different ideas of just war slowly changed to legitimise the conquest of other regions on religious grounds, and modern movements such as Islamic State, not to mention the Taliban in Afghanistan.