Maybe people don't understand this intuitively. In fact, we can give an example to illustrate that the total population of a country is 1 10,000, while the population of young adults is 300,000. Then when there is no war at ordinary times, these 300 thousand young and middle-aged people are engaged in front-line production in various positions. In this way, the productivity of the whole country will be sufficient. But if it happens to be in such a period, then the country needs to donate some of these 300,000 young adults to serve as soldiers. Suppose the number of our conscripts is 65438+ 10,000, then the remaining young adults are only 200,000.
The decrease of teenagers, in ancient society, means the decline of labor ability, which means that some people are transferred to war, and the grain productivity of the whole country is definitely not as good as before. Another point is that after giving birth to children, these soldiers will be transported to eat at the front line. In addition, it is concluded that 65,438+0 ~ 20,000 people are needed to transport grain and grass. If it is difficult to walk in some places, you need a lot of cattle and horses. These people and animals will consume a lot of food and grass on the road, so in general, if it is wartime, it will definitely consume a lot of food and grass.
Of course, in ancient times, in order to alleviate the excessive consumption of food during transportation, some people in power also thought of many ways. For example, during the Qin Dynasty, many roads in Qin Zhi were built for the Xiongnu's Northern Expedition, which could effectively reduce some consumption during transportation. Of course, some people will solve this problem from the above technologies. For example, the wooden ox and flowing horse invented by Zhuge Liang during the Three Kingdoms period belongs to this type.