Why did the four great khanates of Mongolia stand by when Zhu Yuanzhang destroyed the Yuan Dynasty?

Guo (General Theory of National History) once said that the word "Mongolian Empire" never appeared in China's history books. This statement is based on the European view of history, and it is the collective name of all the regimes established by the Mongols at that historical stage. In A.D. 1206, Genghis Khan was selected as the Great Khan of Mongolia, which marked the establishment of what Europeans called the "Mongolian Empire".

In the following decades, the Mongol Empire successively established more than ten countries, including Yuan Empire, Qincha Khanate, Chagatai Khanate, Wokuotai Khanate, ilhan Khanate, Crimea Khanate and Siberia Khanate. Like the princes in the Spring and Autumn Period and the Warring States Period, the Mongolian Khan was nominally the supreme leader, while the emperors of the Yuan Dynasty basically lived as Khan, but all the leaders of the khanate belonged to the "golden family". The total ruling territory of all khanates reached 30 million square kilometers in the highest period, which is an unprecedented huge empire in human history.

In A.D. 1279, Mongolia began to rule the Central Plains after the demise of the Southern Song Dynasty, but during its less than one hundred years of rule, peasant uprisings were endless. In the first year of Hongwu (AD 1368), Zhu Yuanzhang officially proclaimed himself emperor and established Daming. Then the soldiers divided into two roads, all the way south to conquer Zhang Shicheng and Fang Guozhen, and one route led by Xu Da and Chang Yuchun in the Northern Expedition.

The Northern Expedition is a rare war that ended in victory in the history of China. (In the last article, Guo (General Theory of National History) once said that in the history of China, there were Zhuge Liang and others. Most of the Northern Expedition failed. ) In August of the first year of Hongwu, the Ming army breached the capital of the Yuan Dynasty, and the Yuan Dynasty fled north.

Then, why don't more than a dozen khanates, nominally belonging to the Mongolian Empire and so close in blood, stand by and watch instead of helping the Great Khan of the Yuan Dynasty? This is about the struggle between powers. As early as the Qing Dynasty in Song Lizong (A.D. 1259), after Mongo, the great Khan of Mongolia, died in Diaoyutai, Kublai Khan seized the position of Great Khan through a series of struggles and established the Yuan Dynasty. At this time, the Mongolian empire had already seen obvious infighting and division, and wars often broke out between them, which was already a disaster.

So they are willing to sit back and watch the collapse of the Yuan Dynasty, leaving themselves without a strong opponent.