The Spring and Autumn Period and the Warring States Period were turbulent, with wars of all sizes breaking out every day. If it is in the Spring and Autumn Period, then everyone will "point to the end", simply put, to give each other a little lesson, to frustrate each other's vigor, and then get tribute from all sides to become the hegemon of one side, this "Spring and Autumn Five Hegemons" is how it came. At this stage, no one will think about destroying the other country.
However, in the Warring States period, it was different, and countries began to annex wars, "eating" small countries into their own territory. Therefore, the name of "Seven Heroes of the Warring States" refers to the seven most powerful countries at that time. They continued to occupy and acquire their land from the surrounding countries, and the land of these countries snowballed and grew. Seeing which weak and small countries border their own countries, they can't help but directly order the attack.
However, there is such a country, it is called the Song Kingdom, it is very weak, although this country has been brilliant for a period of time, but its current strength is easily annexed by neighboring countries. Let's first take a look at what are the neighbors of the Song Dynasty? There is the State of Wei in the west, the State of Qi in the north, and the State of Chu in the south, any of these countries can easily destroy the State of Song, but these neighbors cannot easily do anything to it.
It depends on its geographical location, it is at the intersection of the State of Wei, the State of Chu, and the State of Qi, and each country has the ability to "eat" it, which means that if one of the three countries takes the lead in taking action, it will cause dissatisfaction from the other two, after all, no one wants to give this piece of fat to others. It is precisely for this reason that this country can serve as a buffer so that these three countries cannot easily attack each other and can develop their domestic strength with peace of mind. And the small land of the Song Dynasty had a reason for existence.
To add: at that time, the economy of the Song Dynasty was very prosperous, and there were many rich merchants here, who knew the way of doing business very well, had a relatively complete business system, and because they were in these key transportation areas, there were different chambers of commerce every day. A place as wealthy as this is surely something that everyone wants.
If the Song Dynasty at that time could recognize its current situation and be able to live in peace and keep to itself, it would still be able to live for a few more years, but the King of Song Kang at that time was really bold, and after the domestic reform was a little successful, he directly opened up the territory, and every country had to get a little land from you, and also destroyed the vine country. At this time, the surrounding powers were not happy, especially the State of Qi, and he also lost the most cities. Therefore, led by the State of Qi, together with Chu and Wei, attacked this small State of Song, and there happened to be a civil unrest in the State of Song at that time, which also accelerated the demise of the State of Song. Finally, in 286 BC, the Song state was finally destroyed by the three great powers bordering it, and King Kang of Song was also captured and killed by the Qi army.
Although the destruction of the Song State was a trivial matter, after all, under the general trend of continuous annexation in the Warring States period, the demise of a small country would not set off too many waves. However, with the fall of the Song state, the State of Chu, the State of Wei, and the State of Qi began to border, which meant that the conflicts between the three sides would become more frequent. Moreover, when dividing up the Song State, the State of Qi had the most benefits because it was the main force and the leader, but as mentioned above, the Economic Prosperity of the Song State, this resource was naturally very much, if the State of Qi took most of it, wouldn't it be detrimental to the other two countries?
Under such conditions, in 284 BC, with Le Yi of the State of Yan as a general, he joined forces with Yan, Qin, Han, Zhao, and Wei to attack the State of Qi, and finally was beaten to the point that there were only two cities, Ju and Jimo, and if there was no Tian Shan later, it was estimated that the State of Qi would have died. Therefore, if you want to get land like the Song Kingdom, you still have to pay some price.
Summary: For the demise of the Song Kingdom, we may also be able to give us some enlightenment, that is, do not be ambitious, be down-to-earth, and strive to improve their ability to break the wrist with others. At the same time, we must also learn to take into account the overall situation, like the State of Qi, which was almost destroyed because of greed for these lands and money.