So war has been talked about before and unless I noticed no one has talked about the ways to win a war, or force a war to end. I’d say a system like stellaris would be good (they keep adding realism in every update). A war exhaustion system, the more ships you lose, troops die, planets lost, and just the wars duration, the faster your war exhaustion goes up. If a side hits 100% war exhaustion they are forced to end the war.
(I think you posted a lot of stuff related to stellaris lately)
But yes, that’s a good idea
That’s because anything space related is usually already done in Stellaris as they are always releasing updates and expansions that keep making the game more complex and realistic. However the Thrive devs can take some of these realistic elements of it and turn it in overdrive by adding extra factors into war exhaustion like the more collateral damage / civilian deaths the higher the enemy war exhaustion, or if they enemy is a terrifying force (empire twice your size) maybe with traits that making you population strong willed to remove that. There are so many potential features involved in just what can end a way aside from completely conquering every planet and outpost it owns.