B:
Actually, I’d say that’s exactly what Objectivists and other radical individualists or libertarians believe.
One rule of thumb I use, though, is surprisingly effective at drawing that line: Is the group/country/whatever water self-sufficent?
If you want to be radical individualist and prove it, move to the Rockies and live by a stream or dig a well.
I would actually be extremely curious to know whether the water in South Ossetia is pumped in from Georgia or down from Russia.
One could argue that the U.S. is not self sufficient (oil, manufacturing), so that’s kind of a strange criterion.
There are lots of people, including myself who fit that criterion, so I don't know that it narrows things down all that much. It also seems a bit arbritrary.
I am just suggesting that drawing that line is, as you previously suggested, difficult, so I think you have to take it on a case-by-case basis.
I will say this: Kosovo set the precedent for this situation.