Okay not sure if this is a bug or what but I was at war with Yor outnumbered them by a heck of a lot and with rangers with about 60 attack to their dreadnaughts with 22 and made a peace treaty with them and got a couple planets. Then gave the altarians me declaring war on Yor just went back to yor on same turn and made a peace treaty again and got a few planets. I repeated this with every major power for the diplomacy bonus it give and I couple minors and gained about 16 star systems in the process. Seems kinda of unfair and they should make it so you can only declare war against a race ince a turn.