And when the Qin State subdued the Han and Wei countries in the east and made them submit, the Qin State also made a great breakthrough in the west.

As early as two years before Qi destroyed Yan and Qin launched their main forces to attack Han and Wei, Qin received a distress letter from its western neighbor, Tho.

As the hegemon of the west, Qin not only had contacts with Xirong, but also had exchanges with Southwest Yi for a long time. As early as the time of Qin Li Gonggong, the Qin people had already had contact with the Shu people on the southwest border, but considering the rugged mountain roads and inconvenient transportation with the southwest, the Qin people did not become interested in the vast territory of the southwest.

For the southwestern countries, the Qin State was originally not interested in them, but the Tho State's request for help made the Qin people begin to have to focus on this land in the south.

The country of Tho is the country established by Du Shang, the king of Shu, after the destruction of the country of Xi Yu and Ping Er, and the division of his brother Du Pujia, so it was also called the country of Pujia. The country of Tho is bordered by Qin to the north, Shu to the south, and Ba to the east.

Although this country was born out of Shu, it hoped to break away from the control of Shu from the day it was founded. Therefore, the national policy of the Tho State has always been to be friendly with the Ba State and the Qin State, hoping that the two countries can help it resist the Shu State!

When the king of Xinshu ascended the throne, he was naturally extremely disgusted with this country that was separated from his own country, but refused to submit, and hoped to replace his own people as the monarch and bring this country under his rule again!

When the king of Shu stabilized his power, he immediately launched an attack on the state of Tho! The Tho State was defeated, so he had to send an envoy to ask the Qin State for help with generous gifts. And at this time, in order to prevent Qin from sending troops and interfering in its war with Tho, Shu also sent envoys and came to Qin with generous gifts, bribed Qin, and hoped that Qin would remain neutral in the war between Shu and Tho!

Sitting at home, King Qin, who didn't do anything, got such a big gift for no reason, it was really joy from heaven! However, as a promising monarch, King Qin will never be satisfied with a mere courtesy!

He immediately summoned the ministers of Qin and asked them what they thought of the war between Shu and Tho.

Xiangguo Zhang Yi immediately objected, in his opinion, the southwest mountain road is rugged, the transportation is inconvenient, and the march is very difficult. And the barbarian land, even if it can be attacked, but it is not of much use, like chicken ribs! At this moment, the Qin State invaded Korea to the east, threatened the Zhou Dynasty, coerced the Son of Heaven to order the world, and established the hegemony of Wang Tu, which was the most important thing!

At this time, Sima Cuo, a young general with a humble status, stood up and sang against the prestige Xiangguo Zhang Yi! In Sima Cuo's view, only a country with a wide country, a large number of people, and rich wealth can be called a great country. Now that the Qin State is only based on the central land, it wants to go east to attack Korea, threaten the Zhou family, and coerce the Son of Heaven to order the world, which is really beyond his strength! And in the current situation of discord among the southwestern countries, the Qin State should take the opportunity to sweep away the countries in one fell swoop, so as to expand the country and enrich the people!

As long as the Qin State has a sufficiently vast territory, a sufficient population, and sufficient wealth, the Qin State is naturally a big country in the world, so why should it coerce a hypothetical Zhou Tianzi? Moreover, under the years of exploration by the Qin State, the Qin people also knew that there were waterways in the land of Bashu that could connect the Chu State! As long as Bashu is destroyed, the Qin State will occupy the upper reaches of the Chu State, so there is hope to destroy the Chu State!

Once the Qin State completes its plan to destroy Chu, then the Qin State will have the possibility of annexing the world!

Such a powerful plan and ambition made King Qin's blood boil! Originally, in the eyes of this monarch, the Qin State dominated the world and became the world's premier overlord, and it was his life's wish to become a monarch like Qi Huan and Jin Wen! However, now Sima Coo has made King Qin see another possibility: let the Qin State lose Shu, Chu, and then the world!

Sima Cuo's plan allowed King Qin to see a farther future. The powerful ambition stimulated the king, so he did not go along with Zhang Yi's plan, but adopted Sima Cuo's plan and sent a large army to intervene in the war in the southwest!

Therefore, after receiving bribes from the State of Tho and the State of Shu, the State of Qin used the generous gifts of these two countries as the capital to start a war, and organized a large army, led by Sima Cuo, to enter from the Golden Bull Road in the southwest to rescue the State of Tho!

After a difficult trek through mountains and rivers, over mountains and mountains, the soldiers of the Qin army finally crossed the Qinling Mountains from the Longdong Plateau and arrived at the territory of the Tho State. Then the Qin army continued to advance, thus entering the Central Sichuan Basin! This is also the first time that the armies of the Chinese countries have entered this area!

When Shu knew that the Qin army had entered Sichuan, the king of Shu, who knew the strength of the Qin state, immediately led the army to crusade, hoping to defeat the Qin army in one fell swoop and drive out the forces of the Qin state when the Qin army was not stable!

And the Qin army did not come here to play. With the help of the guides of the Tho Kingdom, Sima Cuo led a large army to attack the Shu Kingdom. The two sides met at Pujia Pass, and a great battle began.

The powerful army of the Qin State and the advanced war ideas of the Central Plains were not at all something that a country like Shu that was still in the tribal era could resist! In the first battle of Pujia Pass, the Shu army was defeated, the king of Shu fled and was killed, and the Shu country was destroyed!

After Sima Cuo's destruction of Shu, his footsteps did not stop, and he continued to march towards Ba in the east of the Tho country! With such a good example of Shu and the king of Shu, King Ba no longer dared to confront the Qin army, so he took the initiative to surrender, and the country of Ba perished!

In order to better control the land of Bashu, the king of Qin derogated the younger brother of the prince of Shu, and appointed Chen Zhuang as the minister of Shu and Zhang Ruo as the guard of Shu. And at the same time, the kings of Ba and Tho were abolished, and the king of Ba and Tho was derogated as the king, so that the land of Bashu in the southwest was all owned by Qin!

Qin's westward move to Bashu had little impact on the entire world. Hardly anyone knew that the Qin State had directly expanded nearly twice its land in just a few years! There was hardly anyone who realized what a significant impact this move of the Qin State would have on the entire world!

It is said that it is almost, because in the whole world, there is a person who has always been paying attention to the actions of the Qin State! This person is naturally Dai Yan as a traverser!

As a traverser, Dai Yan does not say anything else, the general trend of the whole world, and even the general geographical situation of the whole world, is still very clear. He knows that today's Qin State, because there is Hangu Pass in the east, Dasan Pass in the west, Wuguan in the south, and Xiao Pass in the north, is called the country of abundance with four keys in the world!

The Qin State has such a dangerous situation, as long as the four passes are guarded, it is impossible for the countries of the world to cause any harm to the Qin State! Today's Qin State, as long as it manages the land of Guanzhong well, and when there is a war among the countries of the world, it will naturally have the opportunity to reap the benefits!

The Guanzhong Plain within the four passes is the most stable basic plate of the Qin State! The Qin State has such a stable topography and a solid foundation, and it is called the land of Jincheng Qianli and the country of abundance, which is indeed worthy of the name!

However, Dai Yan knew that compared to the Guanzhong Plain, which was protected by the four passes, the land of Bashu, located in the southwest, was no less than the country of abundance in the Guanzhong Plain!

Not to mention the land of Bashu, surrounded by mountains on all sides, its geographical environment is dangerous, and it is even more above Guanzhong! Moreover, the land of Bashu also has the most important plain area for agriculture, and the area of the Sichuan Basin is far larger than that of the Guanzhong Plain!

This means that the land of Bashu can remain peaceful for a long time. If it is combined with the cultivation and warfare system of the Qin State, it will sooner or later become the most important grain-producing area of the Qin State and an important source of the Qin State's strength!

In real history, the Qin and Zhao states gambled on the fortunes of the country during the Battle of Changping. The Changping front line where the two armies faced each other became a war of attrition, and the distance between the Qin army and Xianyang, the capital of Qin, was more than twice that of the Zhao army from Handan, but in the end, it was the Zhao State that lacked food first!

It is hard to imagine that without the support of a stable and rich land of Bashu, the Qin State would be able to consume the Zhao State with the land of Guanzhong alone, which also owned most of the Hebei Plain!

Dai Yan knew that now that the Qin State had just swallowed the land of Bashu and had not completely annexed it, the strength of the Qin State should not have improved much in a short period of time! However, once the land of Bashu is completely digested, the strength of the Qin State will become extremely terrifying, and by that time, combined with its invincible army, the Qin State will become unstoppable!

Dai Yan also knows that now the Qin State has the land of Guanzhong and seized the land of Bashu, so the land of Hanzhong, which lies between the two places, will become a thorn in the heart of the Qin State!

After all, with the urine nature of the Qin State, the things that were seized naturally hoped to be preserved forever. And today's land of Bashu, and the Qin State, can only be connected by a difficult Golden Bull Road, once this passage is cut off, the Qin State will immediately lose this vast land!

If the Qin State wants to permanently stabilize the land of Bashu, it must get more passages. And between the passages with the land of Bashu, in addition to the Golden Bull Road, there are several other important passages. They are the meridian road, the Baochuan road, the Chencang road and other passages that can connect Hanzhong and Guanzhong, and between Hanzhong and Bashu, there is a rice cang road.

And now the land of Hanzhong is in the hands of the Chu State. This means that if there is a war between Qin and Chu, as long as the Chu State sends troops through Hanzhong and cuts off the Golden Bull Road, the entire Bashu will be lost from the territory of the Qin army!

On the contrary, if the Qin State can own the land of Hanzhong and seize the remaining passages with Shuzhong, then not only will the passage of the Qin State into Shu become smoother, but the land of Shuzhong will also become the real stable territory of the Qin State!

Dai Yan looked at the map of Hanzhong and Bashu that relied on his general memory, plus the map of Hanzhong and Bashu drawn by Nongmo's disciples through investigation, he looked at the lifelines connecting the land of Bashu and Guanzhong, as if he had seen the prelude to the outbreak of war between Qin and Chu!