The difference between aggression and defense tempts the belief that initiating violence is always wrong. One difficulty in understanding the claim is that it’s hard to see how violence is not always wrong (since we can use it to defend ourselves) but it is always wrong to initiate it. This would make sense if the initiation gave the action a moral character, e.g. avalanches hitting towns are not moral evils but to initiate such an avalanche would be. But this is not the sort of difference between aggression and defense. So why is it necessarily wrong to start something that isn’t necessarily wrong? Is it just a practical consideration, i.e. when you’re attacked your options are limited? But then the problem rises again – if violence isn’t wrong, what’s wrong with imitating it, and if it is wrong, why is it okay in defense?
The need to reign in aggression-violence while accepting that it is sometimes just leads first to formalizing and centralizing it. We train and designate those who get to wield aggression. But this sort of power designates sovereignty and so sets up ruler-subject relations. One fascinating move in our shift to modern systems of social organization is that we simultaneously tried to centralize violence and to claim that sovereignty was diffused to the whole people.