I occasionally get emails from a dedicated Battlezone 1 fan who is doing a bit of work on the source code, and the most recent conversation was about alliances in multiplayer not working like they should. Allying with another player causes their units to stop attacking you, but yours are free to continue attacking if you so choose. That's obviously an exploit. He had attempted to tackle the problem in the network code since network play is where the issue crops up.
After a bit of investigation, I found that the network code worked correctly but the "semi-allied" state revealed an insidious--and widespread--bug in the AI system and several player interfaces. Instead of asking "do I think this is an ally/enemy?", many places asked the converse "does this think I am an ally/enemy?". The two have the same answer under normal circumstances, but the half-allied state breaks the symmetry and the second question returns an unexpected result.
This might have gotten fixed for Battlezone 2, but I'd have to check. I'm not sure if alliances work the same way in that game.