[@Ekreture]
THINGS YOU COULD BE INVOLVED IN
-Peace conference obviously, you are now a combatant technically, being Terran-aligned 
-Once Sigma makes a post (probably about raiding human territories), you could be involved somehow. Perhaps the Terran Federation intervention force calls on Gaians to assist (think coalition of the willing type stuff), or it could be a small Gaian frontier colony/settlment (like the ones in Mass Effect 1/2) in another star system, assuming the Gaian Republic has some kind of interstellar presence.
-Your own independent post, possibly detailing some important internal event
-A post involving Earth and the UN, considering they are your closest neighbor, being literally right next to each other.