[Why does the invasion of the Central Plains always come from the Northeast] The nomads from the Central Plains invaded.

There is a very common phenomenon in the history of China: ethnic minorities originating in the northeast frequently invaded the Central Plains, even ruled China, or ruled half of China. Xianbei started from Daxing 'anling and finally marched into Luoyang, establishing the Northern Wei Dynasty: blond hair originated in Songliao Plain, then crossed the Yellow River, and its capital was Kaifeng;

Mongolia rose in Hulunbeier and established the Dayuan Empire.

The Qing Dynasty rose from Baishan Blackwater to unify China.

Why do these powerful invaders not come from the east, south, west, southwest and northwest, but only from the northeast?

I am reminded of Mackinder's "world island" theory.

The concept of "world island" comes from the geographical elements in Mackinder's article "Historical Process" published by the Royal Geographical Society in 1902.

In this article, Mackinder extends geopolitical analysis to a global perspective. Mackinder believes that the earth is composed of two parts: the world island consisting of Europe, Asia and Africa is the largest, most populous and richest land combination in the world; On its edge, there are a series of relatively isolated continents, such as the United States, Australia, Japan and the British Isles.

Mackinder then divided the world island into hinterland and periphery. The most remote part is called hinterland (note: remoteness is not equal to the edge), and the rivers in the hinterland are all inland rivers or pour into the frozen Arctic Ocean. And the history of mankind is the repeated history of the hinterland conquering the edge.

Why can the hinterland conquer the edge? Mackinder's explanation is that the edge cannot enter the hinterland, but the hinterland can enter the edge. The rivers in the hinterland countries are inland rivers or pour into the frozen Arctic Ocean, and the marginal sea power countries that are good at navigation can only look at the ocean and sigh.

In the center of the world island, it is the heartland from the Volga River to the Yangtze River and from the Himalayas to the North Pole. Under the protection of the arctic frozen region and the rolling mountains and deserts in the south, this central region (that is, the hinterland) can only face the threat of land invasion from western Europe. Mackinder believes that this heartland could not be controlled by a single force in the past because of the backward traffic conditions in ancient times. Due to the difficulties of human resources and supply, it is impossible to continue military expansion from east to west or from west to east since ancient times.

Mackinder believes that the emergence of railways has greatly reduced the difficulty for a single big country to rule the central region. When Eurasia is covered by a dense railway network, a powerful continental country will dominate this vast land from the gateway of Eastern Europe. And this will be the prelude for this country to dominate Eurasia and then dominate the world:

Whoever controls eastern Europe will control people's hearts;

Whoever controls the heart zone will control the world island;

Whoever controls the world island will control the whole world.

Mackinder's conclusion assumes that once Germany or Russia control Eastern Europe, it will be a prelude for these two great powers to dominate the world.

It is generally believed that Mackinder's "world island" theory was one of the reasons leading to World War I and World War II.

Mackinder's theory is also very enlightening to understand why the Northeast always occupies the Central Plains.

However, Mackinder believes that the reason why the hinterland frequently conquers the edge, not the other way around, is because of traffic and resources. I think it seems better to explain it by climate or temperature. Countries in cold or temperate regions can easily conquer countries in warm or subtropical regions, and vice versa. Simply put, cold can beat warm, but warm can't beat cold.

If China is regarded as a small "world island", then the northeast is the hinterland and the Central Plains is the edge of the monsoon.

The hinterland can enter the border and has a strong desire to enter the border, because the warm temperate zone and subtropical marginal areas are rich in products, suitable in climate and comfortable in life, which makes people in cold areas yearn for it. People in warm areas of Central Plains have no desire to enter cold areas.

Inference: Poverty affects wealth. Or: backwardness overcomes advanced, and barbarism conquers civilization. This is especially true in the era of cold weapons.

I'm not saying that the northeast is poor. On the contrary, I think the northeast is rich, but the climate in the northeast is bipolar:

Like the North Pole. It is colder than it should be at the same latitude. Whenever winter comes, influenced by Mongolian high pressure and polar air mass, the northwest wind blowing from Siberia, which is known as the "cold pole", prevails in winter, and the cold wave frequently goes south, which is particularly cold in winter.

Like the equator. It has heat that is not available at the same latitude. The summer heat in Northeast China is no different from that in subtropical areas. Even in July and August, Northeast China is tropical. In the 1950s, the geographers in the Soviet Union advocated that the Northeast should be classified as subtropical.

In such an extremely cold and hot environment, what environment can't the Northeast people adapt to?

But I don't think that geographical environment determines fate, and there are many factors at work. It is a systematic project that one nation conquers another and one culture conquers another.

Historically, the Northeast rushed to the Central Plains again and again. After entering the Central Plains, the ethnic minorities in Northeast China have lost their natural fortress without defense in the rear and become the edge of being attacked on all sides, waiting to be conquered by the forces from Northeast China next time.

However, after17th century, this history changed: Russians came. Just like Genghis Khan's expedition to the west, from the east along the Eurasian prairie to the Atlantic Ocean, the Russians began their expedition to the east. They organized Cossacks to cross Siberia along the edge of the northern forest and go straight to the east of Asia, thus occupying the Eurasian steppe.

Their long journey to Wan Li was successful because they moved along the same temperature zone. Since then, Russia has replaced the rule of the grassland people in the north, and the Baikal grassland where Suwu shepherds sheep has become a Russian oil field. The nomadic people in the north were copied from their hometown and lost their unsuspecting hinterland. In history, the threat of nomads from the north going south is gone, and China is facing a new northern hinterland country-Russia.

After several contacts, Russia made the Qing Dynasty lose millions of square kilometers of land. It seems that it has no intention of entering the Central Plains, but it is also eager to go south. Heilongjiang and Wusuli rivers are the result of its southward movement. Vladivostok is their paradise in the Far East, and Harbin used to be.

Whenever I see more than 6,543,800 square kilometers of land lost in the Northeast on the map, I think the most important reason is that the Qing Dynasty did not allow the Central Plains to immigrate to the Northeast. To this end, a side wall-wicker edge was even built to prevent immigrants from the Central Plains from entering the Northeast.

After reading Mackinder's "world island" theory, I have gained an additional gain, that is, I have some understanding of the border ban policy of the Qing Dynasty: maintaining a hinterland without threats and an empty rear.

But the new immigrants still came, from the west thousands of miles away, which the Qing Dynasty did not expect.