That's because at the end of each dynasty, there will always be large-scale chaos and war in society, which is the total outbreak of class contradictions caused by the long-term oppression and exploitation of the people by the ruling class. The whole society and nation need to be completely reshuffled and reorganized. Only in this way can we usher in a new era and a new political power, which will also bring a new development opportunity for the country and the nation. This is the inevitable choice of history, and what seems to be behind it is chaos and retrogression. In fact, it is a kind of motivation and hope for historical progress, and it is the embodiment of the urgent demands of the people. So we should not only observe the surface of things, but also analyze the deeper reasons.