There should be a  conquest option placed into the game so that the AI will fight to the death.  Or have diplomatic options to trade planets and ships.

That way you can tell the enemy ill let you live for this and that? If however he does quit it should go to the pirates or a selected ally if one exist.

An allie tree should be made available so that we can see who our allies are allied with; doesn't make since building a relationship with someone that has hitler in the bed with them.