Liu Zhang asked Liu Bei to help deal with Zhang Lu, but in the end he let Liu Bei take Jiangshan, which was a hatred for Liu Zhang, and also made posterity sigh for him. So what did Liu Zhang think at that time, and how could he do such a stupid thing of "luring wolves into the house"?

(Liu Zhang's stills)
Was Liu Bei's strength at that time still relatively weak, and Liu Zhang did not feel that he was a threat?
If Liu Bei did not have any army before the Battle of Chibi, his strength was very weak. After the Chibi War, Liu Bei, who already owned part of Jingzhou's territory, was actually quite strong.
Besides, if Liu Bei's strength was weak, Liu Zhang would not ask him to help him fight Zhang Lu.
Liu Bei is not only strong, but also a "dragon among men". This was already revealed when he was still wandering around the world. Several times, Cao Cao's advisers advised Cao Cao to kill Liu Bei quickly. Cao Cao was unable to do so at first, but later found that keeping Liu Bei was really suffering from endless troubles, so he repeatedly pursued and beat Liu Bei until the Battle of Chibi and beat himself to the death.
Is no one telling Liu Zhang that Liu Bei is very powerful and must not "lure the wolf into the room"?
Not really. Liu Zhang's master book, Huang Quan, said this to Liu Zhang bluntly: "Liu Bei has the name of a tyrant, and now that he meets him with a part, he is dissatisfied with his heart, and if he treats him as a guest, then a country will not tolerate two masters, which is not the way of self-security." Huang Quan not only said that Liu Bei was a generation of tyrants, but also let Liu Zhang attract attention. At the same time, he also analyzed the problem of not placing Liu Bei after he was brought in. This is indeed a specific question, didn't Liu Zhang think about these things at that time?
(Liu Bei stills)
Is it Liu Zhang who thinks Liu Bei has no ambition?
Apparently not either. Liu Bei has always taken the slogan of "Xingfu Han Room" to attract haojie from all over the world. On the surface, it is "Xingfu Han Room", but everyone understands that the Han Room is obviously unable to "revive". Therefore, all the princes are trying to compete for the world. Liu Bei's mention of this slogan in the absence of a territorial army shows that he is a dangerous element. Isn't it more dangerous when he has the turf?
Since Liu Bei had the ambition of "aiming at the world" and bringing Liu Bei in, Yizhou was definitely part of Liu Bei's plot, and it was the first part. Why did Liu Zhang still do this?
On this subject, I see it this way.
First, the offense that should not be offended.
The person Liu Zhang should least offend was Cao Cao.
Liu Zhang did not have Liu Bei's great ambition to unify the world, as long as he did not fight, he would be satisfied with living a peaceful life. Therefore, when Cao Cao raised troops to attack Jingzhou, he also sent Zhang Song to Jingzhou to pay tribute to Cao Cao. But Cao Cao, a person who has always attached importance to heroes and talents all his life, does not pay much attention to ordinary people. Therefore, in terms of etiquette, zhang songduo is neglected. This made Zhang Song hold a grudge in his heart, and when he returned, he said bad things about Cao Cao in front of Liu Zhang. Let Liu Zhang and Liu Bei unite to fight against Cao Cao.
Liu Zhang believed Zhang Song's words, so he severed relations with Cao Cao and sent troops to help Liu Bei fight Cao Cao.
At that time, Cao Cao went south to Jingzhou, and everyone was fighting Cao Cao, which seemed like a good idea. However, Liu Zhang did not expect that after fighting Cao Cao, Cao Cao came from Hanzhong again, and Zhang Lu in Hanzhong did not have a good relationship with himself, so he could only face Cao Cao's attack alone.
It can be seen from this that Cao Cao really should not be offended by Liu Zhang. Once offended, it is only up to you to take responsibility.
(Cao Cao stills)
Second, believe what should not be believed.
The person Liu Zhang should not believe the most is Zhang Song. In addition, there are Fa Zheng and others. But these people were the closest advisers to him. The closest counselors around him all felt that he was incompetent, and they thought of outsiders in their hearts. Thinking of welcoming Liu Bei in, he was in charge of Yizhou. So he designed to frame him, give him advice, let him make liu bei good, and welcome Liu Bei in.
Historical materials commented that Liu Zhang was kind and kind. In fact, it also shows that he is stupid. He should have a judgment to some extent, and he should also understand who is really good to him and who is setting up a trap for himself. Even the people around him are setting up a set for him, and he can be regarded as a failure as a person.
Third, guess when you shouldn't guess.
Before, everyone told Liu Zhang not to welcome Liu Bei in. But he didn't listen. Welcomed Liu Bei in, and handed over the army to him, asking him to fight Zhang Lu.
However, when he was fighting Zhang Lu, because Zhang Song's brother denounced Zhang Song, he suddenly woke up and made various vigilances against Liu Bei. In fact, after Liu Zhang knew the truth, the most important thing to do at that time was to send Liu Bei out quietly and politely. Or wait for Liu Bei to merge with Zhang Luhuo and let them lose both, and then he will clean up the mess. If Liu Bei eventually took Zhang Lu, he simply let Liu Bei occupy Hanzhong and use Liu Bei to contain Cao Cao. This is the right way to do this.
He did not do this, but instead suspected Liu Bei at this time. Didn't this just give Liu Bei an excuse? Liu Bei still couldn't find an excuse, so it was simply to send an excuse to Liu Bei, waiting for Liu Bei to come and destroy himself in a justified way. When the "wolf" is around, but guess the "wolf", then don't you wait for the "wolf" to reach out and bite yourself?
It can be seen that Liu Zhang is wrong every step and confused to the end. He was given the old nest by Liu Bei, and he also blamed himself.
(Reference: Romance of the Three Kingdoms)