This is weak. Your principles are unrooted. You are merely re-phrasing survival of the fittest which has NOTHING to do with rights at all. Read tehj Declaration of Independence which clearly says where rights come from - our CREATOR. Unless they come from a creator, then they have no moral force whatsoever and can easily be abrogated, stolen, abused, denied.
See, you miss the point. It doesn't matter if I can convince you of my right of self-defense. It merely matters to me that I can assert it.