The decisive factor in the length of a country's existence is not whether a country's ruler governs the country well or badly, but whether the ruler stimulates the main contradictions in society and endangers the living space. In the final analysis, there are two determinants of the length of a country's existence: class contradictions and living space. The policy of the rulers is to alleviate these two contradictions, but the nature of society determines the eternal existence of these two contradictions, and also determines that a country cannot exist forever.
Slave society
Before the Qin and Han dynasties, dynasties generally existed for a long time, also because of class contradictions and the relaxation of living space. Throughout the Xia and Shang dynasties, the demise of the dynasty stemmed from mutual conquests between the princely states. Before Shang Tang destroyed Xia, Shang was a princely state of Xia; before King Wu established the Zhou Dynasty, Zhou was also a vassal state of the Xia Dynasty. But the main class contradiction in these three epochs was not between the princes but between slave owners and slaves. The contradiction between slaves and slave owners was not acute for a long time. The main reason for this was the spaciousness of living space at that time.
The xia dynasty ruled the territory
From the historical description, it is not difficult to find that the Xia Shang Dynasty and the three dynasties of the Xia Shang Dynasty have shown a geometric multiplier of growth. The xia dynasty ruled mainly in the central and western parts of Henan, central and eastern Shaanxi, and southern Shanxi; the Shang Dynasty's rule extended to a large area from the east to the east and west of shanxi, to the west to the east and south of Shaanxi, to the south of Beijing, and to the south of Henan; by the end of the Zhou Dynasty, the scope of its rule had covered most of the middle and lower reaches of the Yangtze River and the Yellow River. Such territorial expansion coincided with population growth, and the living space did not decrease significantly with population growth. The contradiction of living space was greatly reduced, and then the class contradiction between slave owners and slaves was alleviated. Therefore, the change of the Xia Shang Dynasty was not due to irrepressible class contradictions or the seizure of living space, but to the contradictions between the rulers for the distribution of benefits. The intensity of this contradiction is far less intense than the irreconcilable class contradictions that erupted in later generations in order to compete for living space. So it lasts longer.
The scope of Shang Dynasty rule
Since the Qin Dynasty adopted the Shang Martingale Transformation Law, established the private ownership of land, and established a feudal society, the main class contradiction in society has become a contradiction between the landlord and the peasant class around the land. On the other hand, due to the limitations of the economic and environmental conditions of farming, the environment applicable to the development of the agricultural economy has been basically included during the Qin Dynasty. As a result, later dynasties were unable to alleviate the class contradictions brought about by the shrinking living space by expanding their territories.
Eastern Weekend Annual Territory
The main means of production in feudal society were arable land, and when the dynasty was first established, most of it was in the hands of the landlord class, and a small amount was in the hands of the peasant class. With the increase in population and land annexation, the peasant class with the largest population gradually lost the land in its hands, while the population gradually increased and the living space was greatly reduced. The contradiction between the peasant class and the landlord class became increasingly irreconcilable in the process. Therefore, since the beginning of the Qin Dynasty, countless peasant uprisings have broken out in every feudal dynasty. With the outbreak of the Peasants' War, the dynasty gradually fell to extinction, the war caused a large reduction in population, and after the establishment of a new dynasty, the redistribution of the means of production was carried out, so that the newly established dynastic rule was secured. But the expanded living space and the easing of class contradictions in this way are not fundamental solutions. With the development of the times, this contradiction will also appear again.
Territory of the Qin Dynasty
The change of the East and the West is a typical representative of redistribution. At the end of the Western Han Dynasty, the population reached more than 60 million at most, the living space became smaller, the class contradictions were sharp, and the war and chaos were frequent, and the peasant uprisings continued. In the war of more than a decade, the population has been greatly reduced, the living space has increased, and class contradictions have eased. After the establishment of the Eastern Han Dynasty, the population was only 28 million, and before the fall of the Eastern Han Dynasty, the national population also reached more than 65 million. Among the rulers of the Eastern and Western Han Dynasties, the Western Han Dynasty had eight consecutive generations of Ming Emperors, and the Eastern Han Emperor was most famous for his fainting and incompetence. Less than 30 years after the death of emperor Yuan of the Han Dynasty, the Western Han Dynasty collapsed, while the Eastern Han Dynasty, which lacked a Ming Emperor, enjoyed the same 200 years as the Western Han Dynasty. Another common feature at the time of their demise was that the same population reached more than 60 million. This also shows that the relationship between the time of enjoying the country and the ruler is not large, but depends on the sharpness of the main contradictions of society and the amount of living space.
Western han dynasty
The same reasoning also explains why the Qing Dynasty became the longest-lasting dynasty in feudal society. In the early and middle periods of the Qing Dynasty, by the end of the Qianlong Emperor, the qing dynasty expanded its rule from more than 3 million square kilometers to more than 11 million square kilometers. After 1840, the main contradiction of the Qing Dynasty shifted from internal class contradiction to external ethnic contradiction. Therefore, although the Qing Dynasty broke out many large-scale peasant uprisings, the population increased significantly, but it still became the longest-lasting feudal dynasty in China's history!
The Qianlong Emperor
From modern history, it is not difficult to find such a law, when class contradictions are irreconcilable and the living space disappears, external expansion and increasing living space is a good way to alleviate it. For example, in Germany before World War II, the national economy collapsed in the economic crisis, but after Hitler launched the war, Germany's economy, science and technology, and military development were all developing by leaps and bounds. This is not to encourage war, but to say that the Xia Shang Dynasty existed for a long time because the expansion of territory eased class contradictions and expanded the living space. Later dynasties were unable to alleviate class contradictions and increase living space through external expansion. Only through dynastic changes and wars, land redistribution and population reduction, in order to cure the symptoms rather than the root causes of class contradictions to expand the living space. Alleviating contradictions in this way cannot fundamentally alleviate contradictions, so each dynasty cannot jump out of the 300-year cycle.
ps
There is another way to alleviate social contradictions, that is, the development of productive forces. However, throughout the entire history of the development of feudal society in our country, the level of progress of the productive forces has not been able to reach the level of easing class contradictions. But every major productivity advance can give birth to a dynasty that has enjoyed the country for a long time. For example, the Tang Dynasty after the great integration of nationalities, the Song Dynasty after the great development of the southern region, and so on.