So value and collateral damage determine the scale of evil? Whose values system do we use and how much collateral damage is acceptable?
Your Tarkin example is just the larger scale version of collateral damage, policing, and punishment. If we use his values and scale it was acceptable. Who gets to decide? And if a weapon can be used for collateral damage, policing, and punishment then the scale is pretty irrelevant if we accept that collateral damage, policing, and punishment are the uses of weapons. 1 out of 7 billion or 1 billion out of 700 billion.