Without an army to defend your borders the government from which you claim independence could just remove you by force... You would have problems to trade so yo

Without an army to defend your borders the government from which you claim independence could just remove you by force... You would have problems to trade so you would have to be completely self sufficient with food, energy etc. You kind of need to reach some critical mass to be able to organize a functioning nation. Getting to city-states could be viable, but I don't think it can go much farther.