>>23393080That's a matter of policy.
On one hand, you don't have Contolism going around, so PLANT (ZAFT is the name of the armed forces, not the country proper) wouldn't be as much as a threat as Zeon was to the Federation.
On the other, however, the Federation is adamant about it being the sole hegemon of the Earth sphere (regardless of how weak it ends up becoming eventually). Which means in practice that PLANT would have to fight for its independence; they would probably be attacked by the Federation first in order to quell any attempt at a rebellion. The other alternative is to amass enough economic/industrial power within the Earth sphere in order to get the Federation to, at least, recognize them as a neutral power.
I'm leaving aside any and all commentary on Coordinator/Natural conflict (plus Earth supremacists like the Titans), as that's another sack of potatoes that would make a mess of the whole conversation.