In 263 AD, Cao Wei sent Zhong Hui, Wargo and Zhuge Xu to attack Shu. Although the Shu army has the advantage, it has launched a stalemate with the other side. Unexpectedly, however, Wargo led the elite troops to bypass the level tone, cut through the obstacles of the 700-mile mountain, and finally made a detour to Mianzhu, the hinterland of Shu and Han. There were not enough elite soldiers behind the Shu army to resist Wargo. After Liu Chan chose to surrender, Shu was destroyed. Unlike Shu, which perished so quickly, Soochow persisted for more than ten years after that, and finally had to surrender under the massive attack of the Western Jin Dynasty. The reason why Soochow persisted in fighting against the Western Jin Dynasty for so long was that its strength was obviously stronger than that of Shu Han.
Shortly after the demise of Shu Han, Sima Yan forced Wei Emperor to abdicate. Because he took office suddenly, it will take some time to consolidate the internal political power. Coupled with the opposition of the elders of the Western Jin Dynasty, he had to postpone the plan to cut Wu, and the turmoil in the external environment of the Western Jin Dynasty during this period made his plan to cut Wu have to be postponed again and again. When the Western Jin Dynasty was just established, the Xiongnu and Xianbei in the north began to have turmoil, and the Shuhan area had to send troops to station. At that time, the Western Jin Dynasty was busy consolidating the stability of the domestic and international environment and had no spare energy to continue cutting Wu. However, after the demise of Shu Han, the strength gap between Dongwu and Cao Wei increased a lot. Even if the Western Jin did not dare to provoke easily for a period of time, it was only a short-term stability.
With the strength of Soochow at that time, although it was not enough to occupy too much advantage in the confrontation with the Western Jin Dynasty, it could also make the situation in the Western Jin Dynasty turbulent. This is undoubtedly more beneficial to Wu Dong, but Wu Dong's self-sustaining strength can compete with the Western Jin Dynasty, and it did not take too many initiatives to take offensive measures. Finally, after the Western Jin Dynasty recovered from the turmoil, it sent 200,000 troops to attack Wu in six ways. Facing the siege of the Western Jin army, Sun Hao, the Lord of Wu, finally had to surrender.
The reason why Shuhe was repelled has a lot to do with their short-sightedness, and they are more inclined to protect themselves. Blindly seeking self-protection and survival will only become more and more passive, so Zhuge Liang only made the northern expedition, taking attack as the defense, so Shu developed steadily. From this perspective, there are some reasons for the demise of Soochow.