Source: Historical Research on the King of a Kingdom
Let's take a look at how Li Xin and Meng Tian's 200,000 troops failed?
"Historical Records: The Biography of Bai Qi Wang Jian Lie": Li Xin attacked Pinghe, Meng Tian attacked the bed, and broke the Jing army. Xin attacked Yan Ying again, broke it, and then led his troops to the west and met the city father with Meng Tian. Because of this, the Jing people did not give up for three days and three nights, broke Li Xinjun, entered the two walls, killed the seven captains, and the Qin army left.
In 225 BC, Li Xin and Meng Tian led an army of 200,000 to attack the state of Chu, Li Xin led an army to attack Pingyu (now Pingyubei, Henan), and Meng Tian led another army to attack Laiqiu (now Linquan, Anhui).
At that time, the capital of Chu was in Shouchun (now Shou County, Anhui), east of Pingyu and Mengqiu, between Hefei and Huainan in present-day Anhui.
Li Xin defeated the Chu army, and then took advantage of the victory to conquer Yan Ying, after which the Qin state Changping Jun raised an army against Qin in Yingchen, Li Xin and Meng Tian joined forces to the west, and Xiang Yan led the Chu army to follow the Qin army.
Li Xin
The Chu army attacked the Qin army, did not believe it for three consecutive days and three nights, defeated the army of Li Xin and Meng Tian, attacked two military camps, killed seven captains, and the Qin army suffered heavy losses and fled in defeat.
The main reason for Li Xin's defeat was Changpingjun's betrayal in the rear, and if it weren't for Changpingjun's betrayal, would Li Xin have won? Not necessarily.
Although Li Xin's army was progressing smoothly, it did not really engage the Chu army under Xiang Yan, the main force of the Chu army, and it was unknown whether he could destroy the Chu state.
Why did Wang Jian have to destroy Chu with 600,000 people?
1. There are many soldiers in the state of Chu.
Chu is the largest country in the Warring States Period, spanning more than 2,000 miles from east to west and more than 2,000 miles from north to south.
Based on the situation at that time, it is speculated that there were at least 400,000 soldiers in the Chu State.
The state of Chu was the most powerful vassal state
The state of Chu is still martial, although the national strength is weak, but to destroy the state of Chu, it is not an easy task, the Qin army attacked the state of Chu, every time a city was captured, it was necessary to divide a part of the army to occupy it, which was also Li Xin's way of playing.
The state of Chu has hundreds of cities, and if the state of Qin captures one city after another, to the end, there are not many soldiers to fight against the main force of the Chu army, even if 1,000 people are stationed in one city, the 200,000 people of the Qin army are not enough to be stationed in the city.
Wang Jian proposed 600,000 people to destroy Chu, which was obviously calculated, and it was calculated by comprehensively considering the city, troop deployment, and strategy and tactics of Chu, and it was not said casually.
Moreover, the state of Chu has a large territory and great strategic depth, which can make the Qin army fall into the hard battle of Chu, and the Chu army can use the terrain and manpower advantages to harass the Qin army, and it is unknown whether the destruction of the Chu state can succeed at that time.
2. Wang Jian's strategy of destroying Chu.
Wang Jian is of course a stable person, judging from his later performance, his strategy for destroying the Chu State is:
Qin general Wang Qian
Taking advantage of the reason for the strength of the Qin State, he confronted the Chu army and avoided the battle, so as to consume the strength of the Chu State and the sharpness of the Chu army, force the Chu army to take the initiative to seek war, and then use the flaws of the Chu army to destroy the Chu State at one time, without fighting for every city, only eliminating the main force of the Chu army.
"Historical Records: The Biography of Wang Jian Lie": Wang Jian Zhizhi, guarding the wall, refused to fight. Jing Bing counted out the challenge, but he didn't come out. Wang Jian took a break from the day to wash, and was good at eating and drinking, and ate with the soldiers. For a long time, Wang Jian made people ask the joke in the army? So Wang Jian said: The soldiers can be used. Jing Shu challenged and Qin did not come out, but led to the east. Jian Yin raised troops to chase him, ordered the strong man to attack, and broke the Jing army. To Qinan, he killed his general Xiang Yan, and the Jing soldiers were defeated. Qin took advantage of the victory to settle the city of Jingdi.
Wang Jian fights very steadily, no need to take risks, knows how to use his own advantages to consume the Chu State, this style of play is to win and not lose, this is Wang Qian's cleverness, don't take risks, just win, you can't crack it.
The 600,000 Qin troops led by Wang Jian confronted each other on the border of Chu for a year, and the Qin army came from afar and did not go to war, which was beneficial to the Qin army.
In this year, the 600,000 Qin army did nothing, and the daily competition and stone throwing were not a small amount of food consumed every day, but the Qin State had already destroyed the Korean, Zhao, Wei, and Yan States at this time, and had the strength to confront the Chu State.
Qin Jun
But Chu does not have the strength to confront, Chu is not as strong as Qin in all aspects, if the confrontation continues, there will be no food to eat, if the Chu army chooses to attack the Qin army, Wang Jian is not afraid, he has 600,000 people, and he does not divide the army, the strength is here, and the Chu State does not dare to attack.
If the Qin army only had 200,000 men, the Chu State would definitely attack with an overwhelming army of 400,000, and even if the Qin State could defeat the Chu army, it would suffer heavy losses.
When Wang Jian destroyed Zhao, he faced against Li Mu, a famous general of Zhao State, and for a while, Wang Jian was difficult to overcome, but Wang Jian did not attack hard, and used counter-tactics to force King Zhao to remove Li Mu, and then destroyed Zhao State in only 3 months.
If Wang Jian attacked Li Mu, it would definitely be Qin who would take advantage of it in the end, but the Qin army would suffer heavy losses, so it was said that Wang Jian was very stable in the war.
Wang Jian did not divide the troops, the Chu army was not flawed, and the division of troops was easy for the Chu State to break through, and the 600,000 Qin troops were connected together, and the Chu State had no way at all.
Wang Jian needed 600,000 people to destroy Chu
Wang Jian annihilated Chu without taking risks, he used the advantage of strength to consume the Chu State, and the 600,000 troops on the border of the Chu State were considerable pressure, and the Chu army could only confront each other, and when the confrontation could not continue, the Chu army began to retreat eastward.
The retreat of hundreds of thousands of troops is a huge project, Xiang Yan of course has also considered the question of whether the Qin army will pursue, and there must also be the Chu army responsible for breaking the rear, but the Qin army can have 600,000 people, and the 400,000 Chu army can't stop it at all, which is the advantage of having more people.
Moreover, in the field, the Qin army has an absolute advantage in strength, and the name of the tiger and wolf division of the Qin State is not called in vain.
Qin has this strength, and Wang Jian wants to use this advantage to destroy Chu.
If the traditional way of playing is adopted, one city at a time, this battle is not known to be fought until the year of the monkey, and the outcome is unknown, but Wang Jian can attract the main force of the Chu army to confront each other, and thus consume the Chu State, and finally eliminate Xiang Yan's main force in a battle.
Xiang Yan was defeated and killed
The main force of Chu was destroyed, the lord was killed, and the rest of the city was decided.
In order to realize such a strategy, Wang Jian must at least have more troops than the Chu army, the Chu army will be at least 400,000 people, and the Qin army will be at least 50~600,000 people, which is calculated by Wang Qian.
During the Warring States Period, all the people were soldiers, and after the annexation of the Four Kingdoms by the Qin State, I believe that a million troops can also be made up, and only 15~60-year-old men in the country need to be gathered, Wang Jian obviously calculated how many troops the Qin State could make up, and only then reported the figure of 600,000.