In these cases, where there is an unjust aggression, I can only say that it is licit to stop the unjust aggressor. I emphasize the word: "stop". I'm not saying drop bombs, make war, but stop the aggressor. The means used to stop him would have to be evaluated.
Pope FrancisIf the Christian is a restorationist, a legalist, if he wants everything clear and safe, then he will find nothing. Tradition and memory of the past must help us to have the courage to open up new areas to God.
Pope Francis