What Year?

24something AD. There's a timeline in the wiki somewhere and it goes very much in depth into when what happened (starting with a surprise attack on the Alliance at Europa OR Titan I can't remember, by Coalition Forces in 2263 I believe)

according to the unofficial timeline "The mysterious death of the Rheinland Chancellor on-board the destroyed Rheinland cruiser "Donau"" happened in 805AS/2985A.D.. (link) "Little known to most people in Sirius, in reality, it is the beginning of what is eventually known as "The NOMAD War", against the alien race who decimated the human population of Earth centuries ago."