What are the main policies of the Qin State to strengthen the country

Historical records record that the Qin State "has the benefits of Bashu and Hanzhong in the west, the use of raccoon dog and daima in the north, the limit of Wushan and Qianzhong in the south, and the solidity of Cuihan in the east". "A thousand chariots multiplied, fighting a million", the military power is far superior to the other six countries. This superior strategic advantage of Qin laid the foundation for the unification of the six countries.

Qin implemented the strategy of "connecting horizontal and vertical", taking advantage of the mutual suspicion of the six countries to win over the six countries to reconcile with Qin and successfully divide the countries.

After Qin succeeded the Shang Dynasty to change the law, the foundation of the state was basically retained, the law was basically followed, the country was based on the law, constrained by the people, and the productive forces and armaments grew rapidly, so that the six eastern countries had to face up to his existence; Under the persuasion of Su Qin, the six countries formed an alliance with each other to resist the strong Qin, that is, the so-called "joint vertical" - the weak united to attack the strong, but the countries had their own ghosts and interests, but they were defeated by the Qin State in one fell swoop, the alliance broke down, and fell into a melee again; Then, the Qin State worshiped Zhang Yi as the prime minister and lobbied the other countries, that is, the so-called "Lianheng" - one strong thing to attack the weak, it was a few weak countries that joined themselves as vassals out of fear, attacked other weak countries together, and then carved up; It can be vividly understood as: "Hezhong" - the United Three Jin Dynasty (Wei, Korea, Zhao), the north of Yan, the south of Chu, geographically from north to south, is longitudinal, and east and west to resist the Western Emperor Qin, the Eastern Emperor Qi; And Lianheng is that the Qin State relies on its strong hegemony, coerces the weak countries in the east, and attacks other weak countries, geographically from west to east, first get Bashu, stabilize the armament, and then hegemon to the east, which is Lianheng; With the war and the change of status, in the later period (after the Changping War), the Hezong was basically weaker, and Lianheng became a direct surrender to the Qin State; Only then did the final slaughter of the Six Kingdoms one after another;

I don't know if you're satisfied? I once carefully read "The Great Qin Empire", and the author said it in great detail in this part.

The Six Kingdoms once launched the Six Kingdoms War to destroy Qin because of Su Qin's lobbying, and attacked the Qin army with only 150,000 troops from the Six Kingdoms, but the Six Nations were uneven and the soldiers' tactics were old-fashioned. After that, the Qin State first destroyed Ba, and the Shu two countries were the basis, and the six countries of the Central Plains were first allied with others, and the enemy countries were destroyed and then the allies were destroyed, and they were broken one by one, and the six countries of "Han, Zhao, Wei, Chu, Yanqi" were destroyed in turn, and the Central Plains were unified.

On the one hand, they befriended the Qin State, and on the other hand, they encouraged all countries to form an alliance to fight against the Qin State, but the six countries did not agree to always cause the entire alliance to collapse for some trivial things.