I quote "equilibrium" because social structures never stop changing. What I mean is a relatively stable situation where most of the world is not invading the rest of the world. Our present situation is that the larger portion of the population is not invading the rest, though the present trend seems to be in the wrong direction.
I guess an army of thousands could take it over but my hope is that me and my gun toting farming community won't put up with invaders and invaders won't want to take their chances