Natural law and the right of self defense are intrinsically intertwined. As far as governments are concerned, there appears to be two opposing views: 1.people have a right to be armed and defend themselves within reasonable limits; 2:only government has the right to protect and defend their citizens. The difference is pretty stark since the former provides for individual liberty, while the other is opposed to it.
The "right of self-defense" exists only as long as government respects that right. The problems start when government does not honor "rights".
Rulers do not generally want a subject population that can even think about refusing their orders. That gets into dangerous conflict if the population looks at "self-defense" too intensely.
The natural law of self-defense is not subject to government laws of any kind. People will defend themselves against predators using whatever force they can muster to do so. It takes years of indoctrination to suppress the self-defense instinct, and that indoctrination doesn't really imprint for most people.
"Think of it as evolution in action". (Larry Niven). People who won't defend themselves against predators, or evade them, do not survive.
Laws made by government must be in accordance with those natural laws you mentioned, or things go badly.