Vietnam and Laos did not help the Shu Han Dynasty to unify the world, at least for forty or fifty years.
The first is that Vietnam and Laos are weaker than the south and central regions and the Chinese civilization, the language and culture are not as deeply affected by sinicization as the Lingnan region, the cost of governance is certainly quite large, shu Han needs to send some officials, technical craftsmen, cultural scholars, and non-commissioned officers who are familiar with local customs to promote sinicization, but the manpower is obviously insufficient, and the local people who are willing to leave Bashu and enter vietnam and Laos who are still low in productivity are probably not many. The forced dispatch of personnel and military officials to the local construction work will not be effective. In addition, it is necessary to face the resistance of the local people, such as the intermittent rebellion of the Shanyue in the Wu kingdom, which involves the energy of the Wu state, and then restricts its foreign strategy, and if the Shu Han does not handle Vietnam and Laos well, it will also face the same problem.
The second is that the local environment and climate are more humid and hot, insectic and miasma than in the Prachuap Khiri Khan region, and the people of Bashu are not easy to adapt to the local environment and climate, which also increases the difficulty of developing and governing Vietnam and Laos.
The third is that the Southern Central region of the Shu Han Dynasty at that time was not very deep, the land reclamation and cultivation time was not long, the soil fertility had not yet accumulated, although it could also collect some taxes from the local area and levy local people to enrich the army, there were not many officials stationed in the local area, the military strength was about five thousand, at that time, the productivity of Vietnam and Laos was estimated to be not able to exceed the South Central Region, in the history of the development of Lingnan, Lingnan was incorporated into the Central Plains rule in the Qin Shi Huang period, in the two Han Dynasties was developed, to the Sun Wu regime for decades of governance, On the production capacity is still far inferior to the six counties of Jingchu and Jiangdong, the six counties of Jingchu and Jiangdong are the foundation that supports the strength of the State of Wu, so the development and governance of Vietnam and Laos by the Shu Han Dynasty does not take forty or fifty years, I am afraid that there will be no effect, during this period, the financial resources invested in construction should be higher than the wealth obtained from the locality, which not only did not improve the finances of the Shu Han, but also produced consumption.
Strictly speaking, under the jurisdiction of Jiaozhou of the State of Wu, the nine counties of Nanhai, Cangwu, Yulin, Hepu, Jiaotong, Jiuzhen, Nichinan, Zhuya, and Dan'er under the jurisdiction of Jiaozhou of the State of Wu include the northern and central regions of Vietnam, so the Shu Han cannot pay attention here, and the Shu Han may really expand southwards in Laos and Thailand.
Fifth, and most importantly, the difference in national strength between Shu Han and Cao Wei is too great, and the development speed of the two sides is not at one level at all, so Shu Han wants to accumulate strength by recuperating, and it is impossible to compete with Cao Wei, and the only way is to enter the other side's territory, destroy the stable production of the region, and find an opportunity to carry out field battles, to suppress its development momentum to a certain extent by fighting and conquering land, cutting down the army, and consuming the local grain of the other side, and expanding the results of the battle on the other side's territory as much as possible.
One premise of waiting for the other side to change is that the gap in strength between the two sides is not so conspicuous, otherwise just like the chaos of Yuqiu Jian and Zhuge Zhi, the two countries of Shu and Wu also want to take advantage of the opportunity to take advantage of the oil, but after all, Cao Wei's strength is stronger than in cao Cao's era, and these two major rebellions have not achieved the purpose of shaking the Cao Wei regime, so whether Jiang Wei sent troops to the Northern Expedition or Zhuge Ke and Zhu Yixing troops went north, trying to take advantage of the rebellion and cut off Guanzhong and Huainan, they did not achieve their goal.