Earlier, Cao Rui had consulted Sun Zi and Sima Yi and others to discuss how to clean up Shu Wu. Sima Yi, the www.biquge.info of the pen "Fun" Pavilion, thought that Wu should be attacked first, and Sun Zi thought that he should defend against Shu Han, so Cao Rui listened.

In the sixth year of Jianxing (228), Zhuge Liang officially sent troops from Hanzhong to defeat Cao Wei.

【Sima Yi's Discussion】

After the pacification of the Shangyong Rebellion, the border counties were newly attached, and most of them had no household names, and the Wei court was ready to verify and implement them. Emperor Ming then summoned Sima Yi back to the capital and consulted him on this matter, and Sima Yi replied: "Wu Shu constrained the people with a secret net, so the people abandoned them." Our court should only implement the outline of the great government, make it relaxed, and the people will naturally be happy. ”

The Son of Heaven asked Wu Shu again who should be defeated, who should be the first to crusade? Sima Yi replied: "Wu thought that the people of the Central Plains were not accustomed to water warfare, so they dared to scatter in Dongguan. Whoever attacks the enemy must first choke his throat and smash his heart. Xiakou and Dongguan are the throats of thieves. If he led the army to Anhui City, lured Sun Quan to the east, and then led the naval army to Xiakou, taking advantage of its emptiness and attacking it, this move would inevitably break the state of Wu like a divine soldier falling from the sky. Cao Rui thought that these two opinions were right, so he ordered Sima Yi to garrison Yu Wan.

However, Cao Xiu was later deceived by the Wu general Zhou Yi, and was ambushed by Lu Xun in Shiting, defeated and lost, Sima Yi's strategy did not succeed, and was transferred back by Emperor Ming after sending troops.

【Sun Zi's Discussion】

After Zhuge Liang went north to Hanzhong, the Wei court had discussions, thinking that Zhuge Liang could take advantage of Zhuge Liang in Hanzhong to send troops to attack them in one fell swoop, Cao Rui also inted, but Sun Zi thought that Hanzhong, Nanzheng and other places were precipitous, and the world would be in turmoil and the cost would be huge.

According to the record of "The Biography of Sun Zibei", Zhuge Liang was in Nanzheng, and the speaker thought that he could ask for it because he sent a large army, and the emperor did the same to ask for money. Zi said: "Emperor Xiwu conquered Nanzheng, took Zhang Lu, and the battle of Yangping was relieved after the crisis. He also pulled out the Xiahou Yuanjun from the past, and said several words, "Nanzheng is the heavenly prison, and the middle slope valley road is five hundred miles of stone caves", saying that it is deep and dangerous, and he is happy to say that the Yuanjun is also happy. Emperor Wu is holy in the use of soldiers, and the thieves of Chashu inhabit the mountains and rocks, and regard Wu Lu as running in the rivers and lakes, all of which are avoided by the emperor, and do not blame the strength of the soldiers, and do not fight for the wrath of a dynasty. If you march into the south of Zheng to ask for light, the road is both dangerous and obstructive, and it is planned to use elite soldiers and transfer to guard the four southern states to curb the water thieves, and if you use 1560,000 people, you will be more prosperous. The world is in turmoil, and the effort is vast, and His Majesty should be deeply concerned. The strength of the husband to defend the battle, the force is doubled. But with today's soldiers, the generals are assigned to all the important dangers, and the power is enough to shock the strong and calm the frontier, the soldiers and tigers sleep, and the people are fine. In the past few years, China has become more and more prosperous, and Wu Shu and the two captives will abandon themselves. "The emperor is stopped.

Sima Yi, Sun Zi and others all proposed not to crusade against Shu Han for the time being, largely because of the geographical environment of Shu Han at that time, Hanzhong was easy to defend and difficult to attack, and Shu Han tended to be stable internally, so Cao Wei did not have much grasp of Shu internally, and Wu Xiakou and other places were located in Jiangbei, the location was important, and the disadvantage of the navy would be reduced, so Sima Yi felt that there was still hope for dealing with Wu State.

【Reasons for the Northern Expedition】

At that time, although Zhuge Liang had put down the rebellion in the south and the national strength had also recovered, compared with Cao Wei, Shu Han was still unreachable, but Zhuge Liang decided to go north at this time, not only for the long-cherished wish of Liu Bei and others, to restore the Han family, but also something he had planned as early as twenty years.

(1) The Northern Expedition from Yizhou itself was something that had been planned by the "Longzhong Pair". As early as the twelfth year of Jian'an (207), Zhuge Liang had already proposed to occupy Jingzhou and Yizhou, and if there was an opportunity, he would send troops north from the two roads, although there was no Jingzhou now, but Yizhou was still there, so Zhuge Liang was determined to replace Liu Bei to capture Qinchuan all the way from Yizhou.

(2) The inevitable choice for the restoration of the Han dynasty. This is very simple, Liu Bei, Zhuge Liang and others are aiming to revive the Han family, and if they want to revive the Han family, they must crusade against Cao Wei, after all, the old capital of the Han Dynasty, Chang'an, Luoyang and Xuchang are all under the control of Cao Wei, and it is Cao Pi who usurped the throne and seeks Han, so it is inevitable to send troops to fight.

(3) I saw an opportunity. Zhuge Liang chose this time to go north, a very important reason is that Cao Rui, the young lord of Cao Wei, had just come to power, Cao Rui was still an adult, but he was in his early twenties, and his control was not strong, so he was considered by Sun Quan, Zhuge Liang and others to be an opportunity, and all of them sent troops to fight.

And Zhuge Liang first went to the front line in Hanzhong to make preparations on the one hand, and on the other hand to communicate with Meng Da, and after Meng Da was eliminated by Sima Yi, Zhuge Liang also stayed in Hanzhong for a year, and it didn't make much sense to stay, so he officially sent troops.

(4) Transfer contradictions. At that time, Shu Han could be divided into three major parts, one was the Jingzhou group represented by Zhuge Liang, the second was the Dongzhou group represented by Li Yan reluctantly, and the third was the Yizhou local group headed by Qian Zhou and Yonghong. During Liu Zhang's period, the contradiction between the Dongzhou group and the Yizhou group intensified, and finally the local forces represented Zhao Wei to rebel, and the result was pacified, and the Dongzhou group took control of the Yizhou forces.

Later, Liu Bei seized Yizhou, and Liu Zhang fought in the north of Yizhou, and occupied the northern counties of Yizhou, the Dongzhou group was suppressed, after Liu Bei's death, the local forces in Yizhou led by Yonghong in the southern and central regions were in rebellion, and they were pacified by Zhuge Liang soon after. So in general, the Jingzhou Group in Shu Han is the only one and has a stable power, and the other two are not very threatening, so the transfer of internal contradictions is not the main reason for Zhuge Liang's Northern Expedition.

(5) Sticking to it will not succeed. In fact, the main reason for the Northern Expedition of Shu Han is this, the national strength of Shu Han is too weak, and it is necessary to further expand its power, otherwise it is not a long-term strategy to stick to Yizhou.

Among the three families of Wei, Shu and Wu, Wei is the strongest, occupying northern China, Wu also has Yangzhou, Jingzhou, Jiaozhou three states, the power ranks second, only Shu relies on Yizhou alone, the weakest force, although Shu Han has natural dangers, easy to defend and difficult to attack, can not be further is the fate of a target, sooner or later will be captured by others.

So Zhuge Liang must fight out, and the east is Sun Quan, the south is barbarian, and the west is the plateau, so he can only fight the north. In fact, for active attack, defensive counterattack should be more beneficial to Zhuge Liang, but in the period of Cao Pi and Cao Rui, Wei was not interested in crusading against Shu Han, Cao Pi and Cao Rui focused on Jiangdong in the early stage, even if Zhuge Liang arrived in Hanzhong, no one would attack him, which certainly made Shu Han recuperate in peace, but if he wanted to fight out, he could only take the initiative to attack.