The plotline of unruly Earth governments undermining the wider community reflects a pet theory of mine about the ME universe, by the way.
Namely, that the Alliance essentially seized power after the First Contact War, radically de-democratizing humanity's transition into space.
Think about it: the Alliance is like if NATO held parliamentary elections and announced they'd handle foreign policy for member nations.
Yes, there's a parliament, and elections matter, but (as we experience today), in large federations each vote matters less.
Money & influence matter more. So the people with those things jumped on the Alliance's popularity after Shanxi to lock out nat'l govs.
With the best of intentions! They ushered in a golden age. But they left Joe & Jane Public behind. Now, Joe & Jane are catching up.