Just War Theory and Genetic Ethics
When is violence morally acceptable? Just War Theory, developed by Augustine and Aquinas, provides a framework for justifiable violence that's still used by governments today.
The theory has two parts: ius ad bellum (when you can go to war) and ius in bello (how you fight once war starts). For the first part, you need just cause, legitimate authority, right intention, probability of success, last resort, and proportionality. For fighting, you must discriminate between military and civilian targets whilst keeping force proportional to the threat.
Weapons of mass destruction create serious problems for this theory. Nuclear, chemical, and biological weapons can't distinguish between soldiers and civilians, making them potentially immoral under Christian ethics. Yet some argue that possessing these weapons actually prevents their use and maintains peace.
Regarding embryo research and genetic selection, the strong form of sanctity of life says life begins at conception (supported by Jeremiah 1:5). This makes procedures like removing genetic disorders morally questionable, even if they reduce suffering.
Think About It: If small countries can't use powerful weapons for defence, how do they protect themselves against larger aggressors?