Liu Bei's army defeated Yiling, and the next year he became seriously ill, so he recruited Zhuge Liang from Chengdu and asked him to do the following. People are accustomed to calling this kind of thing "orphaned". There was also another person entrusted with a lonely responsibility, Li Yan. Li Yan was appointed as the protector of Zhongdu, commanding the internal and external military forces and stationed in Yong'an. "Zhongdu Protector" is the Metropolitan Governor, equivalent to the current commander-in-chief of the army, and he is in charge of the "army affairs" inside and outside. The political center of Yizhou is in Chengdu, the imperial palace is also here, and military orders should be issued from here. Originally called Yufu, Yong'an was a county on the eastern border that was actually controlled by the Shu Han Dynasty after the defeat of Liu Beiyiling. This raises the question: Why should a "commander-in-chief" of the army who "unifies the internal and external military forces" have to be stationed in a county town on the border?
It should be said that this is the embodiment of Liu Bei's strategic thinking and the worry, that is, in Liu Bei's view, the focus of Shu Han's attack and defense is in the east.
From the offensive point of view, since it was the Three Kingdoms, the focus of the Shu Han should also be Wei and Wu. According to Zhuge Liang's design, there were two offensive routes against the Wei state, one from Hanzhong to the north out of Qinchuan, and the other from Jingzhou to Wanluo. Liu Bei valued Jingzhou. Liu Bei defected to Liu Biao in the sixth year of Jian'an (201 AD) to Guan Yu lost Jingzhou in the twenty-fourth year of Jian'an (219 AD), and in the past twenty years, it should be said that he has won the hearts of the people of Jingzhou and accumulated a lot of popularity, and the backbone members of Zhuge Liang, Huang Zhong, Wei Yan and other backbone members of the Shu Han State are all Jingzhou people. When Guan Yu was stationed in Jingzhou, he once defeated the Cao army at Fancheng, and for a time there was a great posture of directly taking Xu Du. After Guan Yu was secretly attacked by the Eastern Wu people and lost Jingzhou, Liu Bei insisted on cutting down Wu despite the opposition of the people, and his plan should also be to retake Jingzhou first. Shu Han also had a geographical advantage over Eastern Wu, and the logistics supply was certainly more convenient than that of Eastern Wu. In the second year of the Shu Han Dynasty, Liu Bei was defeated by Lu Xun of Eastern Wu and returned to Wu County, but did not return to Chengdu. When Sun Quan heard about it, he was very frightened and took the initiative to send envoys to request peace. This shows that although Liu Bei's Shu Han was defeated, it was still a threat to Eastern Wu. The same was true for the State of Wei, and if the Jiangbei region of Jingzhou at the time of Guan Yu could be restored, the troops could be directly targeted at wanluo and the capital Xu County of the State of Wei.
Defensively, Shu Han's focus was also on the east. In terms of geographical conditions, the Hanzhong region (north) of the Shu Han Dynasty faced only a Wei state, and the geographical conditions of this place were conducive to defense, whether it was Wei attacking Shu or Shu attacking Wei. Later Zhuge Liang, Jiang Wei, and the State of Wei launched a major attack on the State of Shu to illustrate this problem. As far as the east is concerned, although it is also geographically conducive to the defense of the Shu state, this is only relative to the prepared engagement, and if it is not fortified, even the favorable terrain will be in vain. For example, in the seventeenth year of Jian'an (212 AD), after Liu Bei himself captured Mianzhu, Zhuge Liang, Zhang Fei, Zhao Yun and others led their armies up the river and soon captured Yong'an, Jiangzhou, Jiangyang and other cities. It can be seen from this that the favorable geographical conditions did not guarantee Liu Zhang's victory, because the counties and counties of Yizhou could no longer support each other, and the defenders of the city also lost the determination to fight to the end of the war. In other words, both Cao Wei and Eastern Wu could attack Shu Han from east to west, especially Eastern Wu. Only when there is some defense, people will not fight this idea.
Liu Bei stationed Li Yan, a "commander-in-chief" in charge of the national military, on the eastern border, indicating that Liu Bei's focus was on the east rather than the north.
So, why did Li Yan leave Yong'an later? This is the difference between the strategic thinking of Liu Bei and Zhuge Liang. In Liu Bei's view, the east was both the direction for the Shu Han Dynasty to unify the whole country and restore the Han Dynasty (offensive), and it was also the key to defending the country and protecting the family.) In the west, that is, in the Hanzhong region, since it is conducive to defense and is not conducive to attack, it is enough to only use it as a defensive place and leave a general. When Liu Bei first appointed Wei Yan as the Taishou of Hanzhong, but did not let Zhang Fei hold this position, did he have this consideration: Wei Yan was young and could hold this place for a long time? Liu Bei also asked Wei Yan, "You have held such an important position as Taishou in Hanzhong, what are you going to do?" Wei Yan said, "When Cao Cao leads all the armies of the whole country, I will resist him for you; if he sends a general to lead an army of 100,000, I will destroy them for the king." "Wei Yan is only talking about defense here, not offense, which should be very much in line with Liu Bei's strategic considerations." After Liu Bei became emperor, Wei Yan was made a general of Zhenbei, which also fully reflected this. Also, Liu Bei fought Wu under the banner of avenging Guan Yu, but Guan Yu died in the twenty-fourth year of Jian'an (219 AD), and Liu Bei Xingbing was in the second year of Shu Han Zhangwu (222 AD), and there were three years before and after that. In fact, Liu Bei's revenge for Guan Yu was only a banner, and capturing the Jiangnan part of Jingzhou was his military purpose in the first stage of his conquest of Wu. In the course of actual combat, Liu Bei only fought in Jiangnan, while Jiangbei only did defense. After the defeat, Huang Quan, who remained in Jiangbei, could not retreat, so he had to surrender to the State of Wei. Someone wanted to arrest Huang Quan's family, Liu Bei said that he was sorry for Huang Quan, and Huang Quan was not sorry for him, why? Huang Quan, who could not return, belonged to "fleeing", not "surrendering to the enemy". This also proves that at this stage Liu Bei regarded Eastern Wu as an enemy.
With such a strategic thinking, Li Yan, the commander-in-chief of the "unified internal and external military forces," naturally had to stay in the place where war was most likely to occur.
Zhuge Liang, on the other hand, regarded Cao Wei only as an enemy, while he always maintained friendly relations with Eastern Wu. In the year of Liu Bei's death, Zhuge Liang held the actual power of the Shu Han State, and took the initiative to reconcile with Eastern Wu and form an alliance. Throughout his life, Zhuge Liang did not have a war with Eastern Wu, which is the difference between liu bei and Zhuge Liang's strategic thinking. Zhuge Liang's strategic focus was on the north, that is, on the Hanzhong side, and with this guiding ideology, Li Yan gradually moved to the northwest. In the fourth year of Jianxing (226 AD), because Zhuge Liang wanted to move north from Hanzhong, Li Yan was supposed to manage the rear affairs, so he moved from Yong'an to Jiangzhou. In place of Li Yan in Yong'an was the general Chen Zhi, but it was still under the command of Li Yan. In the eighth year of Jianxing (230 AD), because Cao Zhen of the Wei state wanted to attack Hanchuan in three ways, Zhuge Liang ordered Li Yan to lead 20,000 people to Hanzhong. And because Zhuge Liang was going to conquer Wei in the following year, he ordered Li Yan to manage the affairs of the Chancellor's Mansion as the Protector of Zhongdu. At this point, Li Yan completely left the eastern border, and the commander-in-chief became nominal until he was dismissed and exiled the following year.
Liu Bei put Li Yan, the commander-in-chief, on the eastern border, was it too much to use? The main doubt is that there has been no major war in the eastern part of the Shu Han Dynasty. So why hasn't there been a war from east to west? The main reason was that during Li Yan's time in Yong'an, the three kingdoms focused their main energy on internal affairs, and the war on the eastern front was also between Wei and Wu, and neither country could take care of the Shu state for the time being. However, liu bei's arrangement cannot be considered unreasonable. Zhuge Liang's continuous Northern Expedition, whether it is a battle example or a battle result, can be said to be lackluster. Han Xin secretly crossed Chen Cang, quickly swept away the land of the Three Qins, and became an ancient classic example of war, Zhuge Liang took the same road, but it was difficult to have Han Xin's battle results. A contemporary, Zhuge Liang nei did not have the brilliant achievements of Guan Yu when he was in Jingzhou, and his achievements were not as prominent as those of Eastern Wu Lu Xun, so did he have nothing to do with his change of Liu Bei's strategic ideas and personnel arrangements?!