Edward Gibbon, The Decline and Fall of the Roman Empire, (Chatto & Windus, 1960), pp. 524-525: “The demise of Rome was the natural and inevitable effect of immoderate greatness. Prosperity ripened the principle of decay; the cause of destruction multiplied with the extent of conquest; and as soon as time or accident has removed the artificial supports, the stupendous fabric yielded to the pressure of its own weight. The story of its ruin is simple and obvious; and instead of inquiring why the Roman Empire was destroyed, we should rather be surprised that it had subsisted so long.”
There is a lesson here for the West too, if it cares to listen.