Many people think that Zhuge Liang's decision to explore the North was wrong. In fact, on the contrary, Zhuge Liang's move made Shu Han, who should have perished, live for more than ten years. It is right to recuperate, but will the other party wait for it to recuperate in a comfortable position? Actually, it is not, so Zhuge Liang's decision is not wrong.

At first, Liu Bei had no chance to compete for the world. Who was better than Cao Cao and Yuan Shao at that time? However, with the help of Zhuge Liang, he began to change the situation and adopted the route of "Long Zhong Dui", and finally gained a large territory of Jingzhou. In addition, he also made an alliance with Sun Quan, and at present, if it were not for Zhuge Liang, Liu Bei would not have a chance to win one-third of the world.

However, Guan Yu's death deprived Liu Bei of the greatest help. Some people say that Guan Yu's death is the beginning of the decline of Shu Han, which shows how much the sacrifice of Guan Yu has dealt a blow to Liu Bei. It is precisely because of this that Sun Quancai took pains to kill Guan Yu. In his eyes, Jingzhou is no longer important. When Jingzhou fell, Liu Bei had no geographical advantage and didn't have enough troops to fight Wu Dong and Cao Wei. Coupled with geographical restrictions, Liu Bei's grain and grass transportation is difficult, and there is a saying that "the road is difficult to pass, and the sky is difficult to accommodate".

Therefore, in this case, it is not conducive to the rest of Shu Han. If this is really done, it will give Cao Wei time to consolidate his territory and expand his population, but it will make Shu Han fall into a more unbearable situation. It is better to fight according to Zhuge Liang's idea than to wait until the strength of the two countries is even more disparity in the future. The Northern Expedition is an opportunity. If we don't grasp it well, it will even be annexed by Cao Wei. It is precisely because Zhuge Liang understood this that he did not choose to rest.