Recursive argumentation

That's not at all surprising. Legislatures and government representatives involved in treaties tend to ignore natural rights, since their very existence conflicts with them. They also like to deny people their inherent right to self-defense in order to make them more dependent.

> Not to mention philosophical systems or even religions....

Not that it matters, but you're glossing over quite a few philosophical systems here, modern and otherwise. The standard libertarian philosophy based on the Non-Aggression Principle, for example, or really _any_ system of natural rights which does not amount to pacifism, and thus must endorse self-defense to at least some degree. Even the ones which prohibit _personal_ self-defense still tend to allow for both restitution and, for cases of deliberate harm, retribution. They just require one to act through an intermediary (the state, in the form of civil and criminal law). In this case the state is committed to enforcing your rights in some ways (albeit poorly), while infringing on them in others.

Religions deal in right and wrong, not rights, so that's an entirely different issue. Whether it is right or wrong to respond in kind to an aggressive attack is orthogonal to whether the response is _justifiable_--whether the other party can object to the response without hypocrisy. The great thing about the estoppel approach to crime and punishment is that it doesn't matter whether the original action was right or wrong. You don't have to consider the _morality_ if it at all, which is what allows it to work objectively even when the individuals involved don't share a particular moral code. All that matters is that you can't logically object to someone else acting toward you just as you have chosen to act toward them.