After Guan Yu carelessly lost Jingzhou, he defeated Maicheng and was finally defeated and killed, causing heavy losses to the Shu Han clique. Liu Bei therefore decided to raise an army to attack Wu, but was opposed by his courtiers. Everyone felt that the crusade against Eastern Wu was not cost-effective, and the success rate was not high. However, Liu Bei insisted on going his own way, and finally led the army of Shu Han to raise the banner and say that he wanted to avenge Guan Yu. However, was such a war that changed the fate of the Three Kingdoms only out of the deep feelings of Liu Bei and Guan Yu? What is the hidden plot behind Liu Bei's insistence on crusading against Eastern Wu?
It should be said that Liu Bei, as a tyrant in the world, could not be impulsive enough to launch a war for the sake of one person. This also explains why when the news of Zhang Fei's death reached Chengdu, Liu Bei only said "Flying dead", and any other expression of sadness was gone. It can be seen that no matter how deep the brothers are, that's all. The reason why Liu Bei raised the banner to avenge Guan Yu was only hoping to buy people's hearts and minds.
In fact, his real intention was to retake Jingzhou. Because for the Shu Han, if they want to fight for the world, they must occupy Jingzhou, otherwise they will not have the ability to go out and fight the world just by relying on the land of Yizhou. As for expecting Sun Quan's side to cooperate with his own troops from Jingzhou and thus achieve an improved version of the "Longzhong Pair", this idea is simply impossible to achieve. Because Sun Quan never wanted to unify the world, people's greatest wish was just a confrontation between the north and the south. Therefore, for Liu Bei, the Battle of Yiling was a war that Shu Han was bound to launch.
Besides, Liu Bei's age at that time was also a great anxiety. In terms of the monarchs of the Three Kingdoms, Cao Pi had just ascended the throne very young, Sun Quan was also in his prime, only Liu Bei was 60 years old, and he did not have a few years to live. There were already few talents on the Shu Han side, and if Liu Bei himself died again, it would be impossible to expect the flowers in Liu Chan's greenhouse to compete with Sun Quan and Cao Pi for the world. Therefore, it is estimated that Liu Bei wanted to launch a huge war in his lifetime and show the military strength of the Shu state, so as to deter Sun Quan and Cao Pi.
In fact, Liu Bei did the same. Although the Battle of Yiling was defeated, Sun Quan saw the mobilization ability of the Shu Han clique, abandoned the strategic attempt to "hold all the Yangtze River", and instead sent emissaries to Find Liu Bei to express his willingness to negotiate peace, and everyone could continue to be allies. Cao Wei, on the other hand, also gave up the strategy of destroying Shu as soon as possible and turned to the development of internal affairs, which also won the living space of the Shu Han clique for many years.
Of course, if Liu Bei could take back Jingzhou, perhaps the Three Kingdoms era would continue. It is even possible that by virtue of the military victory against Eastern Wu, he would choose to go down the river and occupy the entire Jiangdong region, and then Shu Han and Cao Wei would achieve a north-south confrontation, which would also be a very ideal ending. Therefore, Liu Bei's choice to launch the Battle of Yiling was a choice that would not be harmed. However, no one expected that Lu Xun would come out of nowhere to defeat Liu Bei and make the Shu Han clique completely defeated from then on.