The Battle of Yiling, a high-profile conflict during the Three Kingdoms period, became a key event in history. This duel involved Shu Han and Eastern Wu, Liu Bei raised his army for the sake of shame, but due to the lack of domestic support, Shu Han eventually lost in the military game in which Lu Xun took advantage of the situation in Eastern Wu. The outcome of the Battle of Yiling changed the balance of power between Wei, Shu and Wu, and Shu Han was in decline for a time, and it was difficult to match Cao Wei in the north and Sun Wu in the east, so they had to defend their positions.
Why didn't Cao Wei take advantage of the weakness of Shu Han after the Battle of Yiling and attack directly, but turned his target to Eastern Wu?Cao Wei was actually in a clear advantageous position when facing Shu and Wu in the south. For Cao Wei, it was even more crucial to maintain a balance between the status of great powers and Shu and Wu, in case one side annexed the other, posing a threat to Cao Wei's dominant position. Cao Wei's decision to attack Jiangdong was aimed at maintaining the balance of power between the three kingdoms. As long as this balance was maintained, Cao Wei would be able to maintain his status as a great power and consolidate his domination over the region.
Compared with a direct attack on Shu Han, this strategic choice is more prudent. If Cao Wei chooses to attack Shu Han, he may face two major problems. First, if Eastern Wu attacked at the same time, the two sides would fight for territory, which could cause Cao Wei to lose his advantage. Secondly, if Eastern Wu did not launch an offensive against Shu Han and instead attacked Cao Wei's rear, then Cao Wei would also fall into a passive situation. Therefore, from a comprehensive point of view, the attack on Soochow was a rational move to maintain strategic balance.