Why did Lü Meng capture Guan Yu, but later generations belittled him for 2000? This is because Lu Meng has set an extremely bad precedent! The two armies used the right means to fight, but he chose this method instead.
The crossing of the river in white set a precedent for the military to disguise merchants for surprise attacks, and until then, merchant ships of various countries enjoyed the right of free passage from the flames of war. However, Lü Meng's actions completely changed the situation, and the countries began to strictly inspect the merchant ships passing through the country, and the status of the original neutral merchant ships was destroyed. As the inspection deepened, countries found that there were not a few enemy soldiers disguised as merchants, which made the passage of simple merchant ships complicated and time-consuming, and seriously hindered international and economic exchanges. At the same time, Lü Meng's white-clothed crossing of the river also aroused suspicion and hostility between countries. Fears of a recurrence of similar camouflage tactics that would increase the risk of war have exacerbated regional tensions and sown the seeds of future war.
Therefore, although the victory of the white-clothed crossing of the river was infamous, it became an extremely negative and distorted example.
Opened a precedent of backstabbing an ally to kill the main general of an ally: Some people believe that Lü Meng's "crossing the river in white to kill Guan Yu" has "legitimacy" because "Liu Bei borrowed Jingzhou, and he borrowed but did not pay back" treacherous first. However, according to the "Chronicles of the Three Kingdoms" and "Book of Jin" and other historical records, Jingzhou was originally the territory of the warlord Liu Biao, and after Liu Biao's death, the second son surrendered to Cao Cao, and the eldest son Liu Qi allied with Liu Bei. Therefore, after defeating the "Cao Cao's southern invasion" in the Battle of Chibi, Liu Bei wrote a letter hoping to seal "Liu Qi as the pastor of Jingzhou". In terms of righteousness, Jingzhou belongs to Liu Qi, the eldest son of Liu Biao, and there is no such thing as borrowing Jingzhou.
Break the Covenant: The Sun-Liu alliance has been formed to resist Cao Wei together. And Lü Meng took advantage of Guan Yu's unpreparedness, reneged on the covenant, and won by surprise, which was actually a betrayal of his allies.
Influence on later generations: The Sun-Liu alliance broke down, and the contradictions between Shu Han and Eastern Wu deepened, leading to more brutal wars between the three kingdoms. Lü Meng's behavior also made later generations of generals realize that war is not only a head-to-head confrontation, but also can be won through stratagem and strategy.
In the war years, even if the situation forced him, he could not easily abandon the bottom line of morality, could not violate human nature, and maintained basic rationality, otherwise he would lose his reputation after gaining results like Lu Meng.