Nuclear Warfare Is Not a Game of Risk

This is why those Catholics and other Christians who hold that armed force may sometimes be morally justifiable (i.e., just war theory) tend to be "nuclear pacifists” — nuclear war would probably be total war, violating just war principles such as noncombatant immunity and proportionality. And a "first use" to prevent an attack that is not both imminent and grave raises even more red flags.