Cao Cao is suspicious, and he knows that it is the characteristic of every general, so he uses this available situation to set a trap for others. When the enemy thought he knew the truth, he was still in Cao Cao's calculation, and he didn't give the enemy a chance to pull back.
In fact, military and politics are the same. People in the military and politics don't trust anyone. Cao Cao did not directly tell the enemy information in the form of language, but made the other party think that he had inadvertently revealed the "facts" by hinting. As long as the other party believes it, he has been trapped. . . . The above is my opinion, I hope I can help you.
Please see the information below.
2 1 1 year, Ma Chao and Han Sui sent troops to rebel against Cao Cao and killed Tongguan, an important town in Guanzhong. In July, Cao Cao led the troops in counterinsurgency.
After Cao Cao stationed troops near Tongguan, he made a gesture of storm, and secretly sent Huang Xu, Zhu Ling and other generals to sneak into Pubanjin at night and set up camp in Xihe. Then, Cao Cao led his troops across the river to the north, occupied the mouth of Weishui, and set more suspected soldiers to sneak his troops across the river and gather in Weishui. On the surface, Cao Cao is ordering soldiers to dig tunnels, build Abatis and make a defensive appearance. Ma Chao failed in many challenges and dared not attack easily, so he had to ask for concessions and peace. Cao Cao listened to Jia Xu. Pretend to agree to Ma Chao's peace terms.
At this moment, Han Sui requested to see Cao Cao. Han Sui and Cao Cao were humble in the same year and worked hard together in Beijing. The purpose of Han Sui's trip was to lobby Cao Cao to withdraw, but Cao Cao only told him the past and laughed it off. Ma Chao became suspicious of Han Sui after learning about it. A few days later, Cao Cao sent another letter to Han Sui, many of which were altered, which made Ma Chao more suspicious.
Just when Ma Chao was on guard against Han Sui, Cao Cao suddenly launched a large-scale attack on Ma Chao. First, they challenged lightly, and then attacked in a big way ... Ma Chao and Han Sui were in a panic, and finally ended in failure.
After the victory of the battle, someone asked Cao Cao about his combat intention. Cao Cao said, "The enemy will defend Tongguan. If I enter the land east of the river, the enemy will inevitably lead troops to guard the ferry. In that case, we can't cross the Xihe River. Therefore, I will first gather heavy troops in Tongguan to attract all enemy guards, so that the enemy garrison in Xihe River will be empty, and Huang Xu and Zhu Ling can easily cross the river. When I led the army north, because Huang Xu and Zhu Ling occupied favorable terrain, the enemy did not dare to compete with me for the Xihe River. After crossing the river, we dug tunnels and built Abatis, but we couldn't insist. We just pretend to be weak and arrogant to the enemy soldiers. When the enemy made peace, I made a false promise and caught the enemy off guard. Once our army attacks, the enemy will lose his armor and be unable to resist. Use soldiers to pay attention to change without being rigid. "