Zoners - why they do exist?

[The Savage]

The major problem, is that people think of Zoners as space pacifists and not space libertarians. The difference is that one can and will shoot you.

I think the other problem is that ID doesn't allow them to do so, I mean, they aren't even allowed to enforce Zoner laws around the Freeports, according to the ID. They can only attack in self-defence of oneself, base and other Zoners. (I think the very same problem touches GMG ID, which doesn't have line about violating the GMG law - instead, they have line about the contraband.)

Or, that's what EXACTLY "defending an allied bases" line is?