https://victorhanson.com/civilizational-killers-part-one-perversion-of-the-law/
No civilization can continue if its bedrock values and institutions are eroding—especially if the effort to save them is considered worse than their destruction.
When we look to the civilizational decline of the Greek polis, the Roman Empire, the Byzantine Empire, or of Europe in the 1930s we learn that erosion is a result of internal choices, and usually a matter of failing to adhere to time-honored customs and traditions, while evolving to meet new threats.
In the case of the autonomous Greek polis, the culprit was the inability of some 1,500 city-states to create a workable federal system for the common defense of Hellas—when threatened by Philip and Alexander. The Roman Empire was not able to maintain a common culture among its 70 million varied residents, nor to increase productivity to pay for always greater entitlements, or to systematize imperial succession, or inculcate Romanity among an increasingly diverse population.
For the Byzantines, it is hard to criticize an empire that sustained 1,100 years of continuous civilization. But in the fifteenth century, it failed to evolve into a partnership with a dynamic Western Christendom, especially after the damage suffered during the Fourth Crusade, to create a common front against Ottoman Islamism. Nor was a shrinking Constantinople able to attract Europeans into the empire, much less to convert Anatolians into Orthodox Christians.