The VOX server has the ability to restart itself when it detects a problem. This causes a loss of VOX for most, but not neccessarily all players, depending on the state of the local client when it happens.
The point was 1) the VOX server has no idea what a "country" is., 2) if the VOX server dies and does not come back, then everyone loses VOX, and 3) loss of VOX is not neccessarily the server, as VOX is all done via UDP, all one has to do is lose a few packets to lose VOX. Anyone on a wireless connection will suffer more VOX issues than a land line will, but land lines are also subject to packet loss.