Yong' an weather

Before the battle of Yiling, Cao Pi thought that Liu Bei would not attack Sun Quan. In the battle of Yiling, he chose to sit still and watch the tiger pounce. After the battle of Yiling, Liu Bei was defeated and chose to attack Wu Dong. This is Cao Pi's attitude before, during and after the whole Yiling War. Cao Pi's attitude came from the mainstream attitude in Wei and Jin Dynasties to a great extent.

After the battle of Yiling, Liu Beijun was almost completely annihilated. Huang Quan, who stayed in Jiangbei, led 10,000 soldiers to surrender to Cao Wei because of the posterior problem. After Liu Bei fled back to Yong 'an, there was only one Yizhou in Shu Han, and the standing army was less than 100 thousand. Moreover, due to defeat and low morale, domestic reactionary forces are ready to move. From the common sense, as long as Cao Pi chooses to attack Shu Han, the destruction of Shu Han is almost at hand, and it can obviously be eaten.

Liu Bei launched the battle of Yiling.

First of all, from the strategic analysis.

After Guan Yu lost Jingzhou, Sun Quan seized three counties in Jingzhou belonging to Liu Bei. At this point, all seven counties in Jingzhou except Nanyang County were occupied by Sun Quan, and Sun Quan became the second largest force in the three countries after Cao Wei, and its strength was twice that of Shu Han.

The mainstream opinion of Cao Wei court is that Shu Han is a small country, and the famous Guan Yu was killed again. Shu Han did not have a good general, nor did he have the strength to fight abroad, so Shu Han was not enough to pose a threat to Cao Wei. On the contrary, Wu Dong's power has been strengthened because it has acquired the population and territory of three counties in Jingzhou. Cao Wei believed that the Wu Dong regime was the biggest strategic enemy, so Cao Wei deployed the main military forces on the border with Wu Dong.

Strategically speaking, Cao Wei has more than one enemy. Cao Wei is surrounded by Shu Han regime, Wu Dong regime and Liaodong Gongsun regime, and there are Xiongnu, Wuhuan people and Xianbei people in the northwest. The biggest threat to Cao Wei is Wu Dong, actually the Shu Han and Gong Sun families in Liaodong, and finally the Huns, Wu Huan and Xianbei people in the northwest.

Three kingdoms tripartite confrontation map

Based on the principle that two wars cannot be launched at the same time strategically, Cao Wei can only launch a strategic attack in one direction. If Cao Wei chooses to attack Shu Han, the Soochow regime in the south of Cao Wei may attack itself. However, if Cao Wei chooses to attack Dongwu, Shu Han at this time is incapable of waging war, so he can't pose a threat to Cao Wei behind his back. Relatively speaking, Cao Wei's strategic threat to attack Dongwu is the least.

Therefore, preventing Shu from attacking Wu is the established strategy of Cao Wei regime, and Cao Pi can't easily change the national policy and attack.

Second, from the geographical analysis.

Look at the map and you will know that after Guan Yu lost Jingzhou, the boundary between Cao Wei and Shu Han became the land from Qinchuan in Hanzhong to Guanzhong, and the junction of Shangyong County in Jingzhou and Ba County in Yizhou. In order to attack Shu Han, Cao Wei had to deploy a large number of troops from Jingzhou Theater in the middle and Hefei Theater in the east to Guanzhong area.

Battle of Yiling

That is to say, the troops stationed in Anhui, Jiangsu, Henan and Hubei today will be transferred to Shaanxi, and then the troops will enter Hanzhong through the 800-mile Shu Road, which is difficult to reach the sky, in order to attack. Cao Wei soldiers not only have to cross thousands of kilometers of roads, but also this large-scale mobilization can not be realized for a while.

In addition, attacking Shu Han from Guanzhong and Liang Yong, whether marching, transporting grain or supplying materials, are restricted by local road conditions. There are only five roads from Guanzhong to Hanzhong, most of which are plank roads built on cliffs. Later, Cao Zhen cut Shu in the Meridian Valley for a month, but was forced to retreat because of the weather. The reason is that the road is difficult and the weather is changeable. Cao Shuang, the son of Cao Zhen, attacked Shu.

Although Shu Han was weak, there was a general Wei Yan guarding it in Hanzhong at that time, and Shu Han could use the natural barrier to reach the point of "one person guarding it, ten thousand people can't". This is not strong, enough troops can occupy it. If Cao Wei concentrates more than half of the country's troops to attack Shu Han, in case of failure due to road reasons or weather reasons, Cao Wei will face great risks, so Wu Dong may attack. At that time, Cao Wei could not save anything, so he withdrew from the Guanzhong front.

Cao Pi attacked Wu.

On the contrary, Cao Wei and Dongwu were originally on the border, and the border between the two countries was roughly the Yangtze River. If Cao Wei wants to attack the Dongwu regime, it will be easier. He only needs to build a ship, and does not need large-scale troop deployment or large-scale grain transportation. Even if there is a war between Cao Wei and Soochow, it is not easy for Shu Han to attack the Guanzhong area of Cao Wei, because it is equally difficult for Shu Han to cross Qinchuan 800 miles.

Therefore, after the Yiling War, Cao Pi chose to attack the Dongwu regime, which was much easier, shorter and easier to operate than attacking the Han Shu regime, and there was no need to dispatch troops on a large scale. Anyone else will choose to attack Dongwu.

Third, from the strategic analysis.

Strategically, Cao Wei's choice to attack Wu Dong was also a correct strategy at that time, and as early as the Yiling War, Ye Liu, the lieutenant, suggested that Cao Pi and Liu Bei attack Sun Quan. Obviously, Ye Liu's suggestion is correct.

Sun quan

Because Liu Bei's intention to attack Sun Quan was far stronger than Sun Quan's intention to attack Liu Bei, Guan Yu was killed by Sun Quan and three counties in Jingzhou were taken away by Sun Quan. Liu Bei hated Sun Quan and gnashed his teeth. Zhao Yun advised Liu Bei not to attack Wu, but Liu Bei wouldn't listen. In addition, Jingzhou people occupied an absolute advantage in the court of Shu and Han, and all advocated the recovery of Jingzhou.

Therefore, it is very important for Shu Han to recapture Jingzhou. In the battle of Yiling, xelloss chose to stand by, just to make Shu Han and Wu Dong lose both sides, and then benefit the fisherman. However, Liu Bei's defeat in the battle of Yiling was too sudden, almost in an instant. In just one month, Liu Bei fled back to Yong 'an from the defeated land. Although xelloss is always ready to grab booty, he obviously doesn't want to move the battle of Yiling.

Therefore, the final development confirmed the correctness of Ye Liu's previous proposal. It should be right for Cao Pi to jointly besiege Sun Quan with Liu Bei strategically, because Sun Quan's strength began to grow after the annexation of Jingzhou. Although Sun Quan surrendered to Xelloss on the surface, in fact, Sun Quan only fooled Xelloss, and Xelloss could not sit idly by and watch Sun Quan grow stronger. If Sun Quan annexed Shu Han, the world would go from bad to worse in the Northern and Southern Dynasties, which was obviously not what Cao Pi hoped.

The battle of Yiling Wu Dong protection map

In the later period of Yiling War, Soochow also showed the intention of annexing Shu Han. Chen Bing's Dongwu army is on the front line of Wushan and Zigui, just across the river from Yongan, ready to continue westward. However, due to the arrival of Zhao Yun reinforcements, Liu Bei fled back to Yong 'an, and the Shu army in Yong 'an was close to 20,000. Most importantly, however, Cao Pi in the north stared at Soochow with his eyes. If Wu Dong wants to attack Shu Han, it will be a disaster for Wu Dong.

Therefore, Cao Pi thinks that only Wu Dong's Sun Quan can attack, and Shu Han is too far away, so he chooses to attack Wu Dong instead of Shu Han.