When we look back at the time of Qin Shi Huang, the fact that he built the Great Wall has always been a topic that has been constantly raised. Today, we talk about the great cultural heritage of the Great Wall, and the sweat and hard work of the people when he built the Great Wall has always been an indelible memory.
In the face of the threat from the north, Qin Shi Huang, who established a centralized state through conquest and killing, slowed down the horse's hooves and chose a relatively mild response - building the Great Wall.
There is a very surprising discovery in the statistics of modern science. That is, the direction of the Great Wall is highly consistent with the 400 mm precipitation contour. The amount of precipitation determines that the south side of the Great Wall is suitable for agriculture and the north side is suitable for nomadic herding. Judging from the map, the Great Wall of Qin is also basically the dividing line between China's agricultural civilization and grassland civilization. For uncultivable land, even if it is knocked down, it is useless.
Qin Shi Huang built the Great Wall, the most direct effect is to block the invincible cavalry of the nomadic civilization outside the Great Wall, so that the soldiers of the Central Plains do not have to resist the iron hooves of others. The Huns have no cavalry, it is not a broken leg, but completely paralyzed, and I can eat as much as you come in.
Ancient China has always been an agrarian economy. This is different from the development of the industrial revolution in the West and the colonization of the whole world, and it is different from the Western countries. Western countries are engaged in an industrial economy, and they must expand their territory and implement colonial rule in Africa, Latin America, and other places.
The agricultural economy has no special requirements for geographical expansion. If there is a requirement, it is a requirement that this area should be able to produce crops, and if it does not produce crops, it will not be too concerned.
It was for this reason that Qin Shi Huang repaired the Great Wall. As long as you can stop this good land of your own family and prevent others from attacking, you can't make a lot of effort to rob and grab the territory of the ethnic minorities in the north.
Why didn't Qin Shi Huang destroy the Xiongnu?
It's not that I don't want to, but I don't have enough power. There was an emperor in Chinese history who attacked the Xiongnu fiercely, yes, it was Emperor Wu of the Han Dynasty - this thing did not attack the Xiongnu with all his might, and finally beat this group of people to the courage to flee to the west, but it made the Westerners choke enough. What was the result of Emperor Wu of the Han Dynasty fighting the Xiongnu? **Jing's accumulated wealth in the past hundred years was spilled in the era of Emperor Wu, just to fight a Huns, and ended up with a bad soldier, labor and money, fortunately, he also won the war, otherwise he might not be poked by someone.
The second effect is also to alleviate the problem of military strength in the Qin Dynasty. The construction of the Great Wall avoided the embarrassment of the Qin army's defense - this is also the reason why the Qin army did not run out to chase them.
Third, the requisition of the people to build the Great Wall must have a great effect on the rule of the Qin Dynasty. It is true that the Qin Dynasty still came to an end under the attack of the remnants of the Six Kingdoms, but this was a long time later.
Qin annihilated the six countries to unify the world, and the integration of people from different countries was a problem. In fact, not only the Great Wall, but also Qin Shi Huang always engaged in this large-scale project, all of which had this aspect in mind.
Even if the Xiongnu were defeated, it would be of little use to the Qin State. First of all, ideologically, the "important clothes" and "wild clothes" outside China do not belong to China. Even King Wuling of Zhao once adopted the "Hufu Cavalry Shooting" in order to revitalize the Zhao State, he never regarded the nomads as his own. Secondly, even if the Xiongnu were really included in the territory of Qin, would it really have any positive effect on Qin? After Qin Shi Huang unified the six countries, he confiscated all the ** in the whole world and cast them into 12 gold people, if he really beat the Xiongnu, then the Xiongnu's cavalry shooting was no longer allowed, and then what did they rely on to survive? It is impossible for them to develop agriculture in the grasslands and deserts. In order to prevent the Xiongnu from committing rebellion, the Qin state had to spend money to feed them, which was too costly for the tired Qin Empire and had little benefit. In comparison, the southern expedition to Baiyue is too cost-effective.