I would be very surprised if there was a sanction against the defender of a base - given reasonable and serious roleplay - because he has the line "can only engage in self-defence". Of course the fighting has to be contained to the base perimeter and there cannot be forward defense moves, etc. It might also help to have the conflict roleplayed on the forums, so that it is visible and acknowledged, so that reports are not even necessary because people know what to expect.
