A central authority can only steer as far as its message round trip stays shorter than the time it takes circumstances to change; past that point an order arrives after the situation it answered has moved, and decisions pass to whoever is closest. In Ansary's account the radius of control grew from about 30 miles on foot to continental empires only as messaging sped up. Read into P7: when the rate of change rises faster than the loop speeds up, the radius of central correction shrinks, so correction that keeps pace has to sit close to the action, with who may decide at the edge settled in advance, rather than be routed to a centre.

Evidence 4 passages

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When the governor's next order arrives, it might no longer fit the situation.
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Out there, if an emergency comes up, people can't wait for orders. Someone closer to the scene has to make a decision.
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The speed at which a message could travel determined how big an area one authority could govern.
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Given the technology of the time, it had surely reached its absolute administrative limit.

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