The Galaxy is a privately funded fleet. I think whoever first came up with the Aliens analogy is right, the Galaxy sees the Vajra and potential weapons technology (or actual, the -27 has an internal fold device and that, well, not sure what to call it... super dimension gun... just like the lobsters).
Ma2ha3, I'm not being a smartass when I say this, I do believe you've missed something along the way. Whether it was an episode, or a part of a few episodes. Go back and re-watch them all, the Galaxy's involvement is clear.