CCC 2313
Life in Christ›SECTION TWO THE TEN COMMANDMENTS›CHAPTER TWO YOU SHALL LOVE YOUR NEIGHBOR AS YOURSELF›III. Safeguarding Peace
Non-combatants, wounded soldiers, and prisoners must be respected and treated humanely. Actions deliberately contrary to the law of nations and to its universal principles are crimes, as are the orders that command such actions. Blind obedience does not suffice to excuse those who carry them out. Thus the extermination of a people, nation, or ethnic minority must be condemned as a mortal sin. One is morally bound to resist orders that command genocide.