People seem to think that a political system of complete control can never exist or sustain itself on earth. I don�t know why they think this. The actual size of the Earth is somewhat arbitrarily related to our evolution; humans could have evolved on an Earth with nothing but ocean west of europe to asia; and a lot of asia could have been missing as well. They could have come out of africa and just found a lot of water. A world this size would be a lot easier to control.
Scientific methods for preventing change can develop a lot faster than evolution can invent new ways out of it; and if the system specifically enforces conformity from an early age, then most individuals who could effect change as adults would be gotten rid of very early on anyway. With a good enough system of control, it would not be impossible to put humanity into a holding pattern. This poses a major existential risk, if you consider this to be a failure. So I think the optimum path for the way we conduct our affairs should give credence to this possibility; giving up a little centralization will slow down the optimum path of development but will reduce the chance of a dead-end.
If you put some chickens in a steel cage with an automatic food dispenser, life will not find a way. You could wait a million years, but they will never evolve their way out of it. If you control evolution by killing any chicken which diverges from standard behavior, they will have even less chance of ever getting out. The machine might break down, but the chickens would all die. It'd be very unlikely that the steel cage would wear away before the machine broke down or ran out of food. There's just a tiny possibility that they break out, overrun the whole planet, evolve into sentient chicken-beings, and later discover the cage and understand where they came from.
So, we should place a lot of value in never getting put into the cage in the first place.