When an empire is formed through conquest, there is an inherent bias towards predatory behavior rather than a drive towards unity and mutuality. While this provides the vital force required to conquer and thereby grow an empire, it has the built-in weakness that eventually, unless it could find a way to transform itself into one that respects, supports and provides equality to all its conquered peoples, it will simply react as a predator to its prey and devour the energy of the conquered people. This may involve resource allocation, but may also include absorbing the best and highest powers of intellect, mind and creativity into the imperial core at the expense of the extremities. Eventually, the creativity and dynamism are used up, and the empire weakens and dissolves.
Sri Aurobindo observes: “The weakness of the old empire-unities created by conquest was that they tended to destroy the smaller units they assimilated, as did imperial Rome, and to turn them into food for the life of the dominant organ. … In such a method, however, the exhaustion of the life in the subject parts must end by leaving the dominant voracious centre without any source for new storage of energy. At first the best intellectual force of the conquered provinces flowed to Rome and their vital energy poured into it a great supply of military force and governing ability, but eventually both failed and first the intellectual energy of Rome and then its military and political ability died away in the midst of the general death. Nor would Roman civilisation have lived even fro so long but for the new ideas and motives it received from the East. … When the Roman grasp loosened, the world which it had held so firmly constricted had been for long a huge, decorous, magnificently organised death-in-life incapable of new origination or self-regeneration; vitality could only be restored through the inrush of the vigorous barbarian world from the plains of Germany, the steppes beyond the Danube and the deserts of Arabia. Dissolution had to precede a movement of sounder construction.”
Sri Aurobindo, The Ideal of Human Unity, Part One, Chapter 12, The Ancient Cycle of Prenational Empire-Building–The Modern Cycle of Nation-Building, pp. 98-99