Reading the comments on this thread makes me wonder why there would be an assumption that a) separating from the Federation would be a difficult process to begin with, and, b) that a split is based on xenophobia. I also wonder why is there a need to even join the Federation, or align with any particular power within the Alpha Quadrant. And finally, there could be any number of reasons to remain independent from the Federation. Just because the Federation is the default "good guys", that doesn't mean a government's orientation aligns with the Federation's objectives overall, which could be perfectly benign.