Why were the Sichuan Basin and Tarim Basin sometimes independent from central Chinese rule?

The Sichuan Basin and the Tarim Basin have historically experienced periods of independence or separation from central Chinese rule primarily due to their distinct geographical isolation and economic self-sufficiency.

Sichuan Basin

The Sichuan Basin is surrounded by high mountain ranges—including the Plateau of Tibet to the west, the Yunnan-Guizhou Plateau to the south, and the Wu and Daba mountains to the east and north—which create a natural fortress. This geographic inaccessibility, combined with its vast area, large population, and ability to remain economically self-sufficient, has historically encouraged political separatism. For example, during the Three Kingdoms period, the region functioned as the independent Shu-Han kingdom, and in the early 20th century, it was fragmented among various military warlords.12

Tarim Basin

The Tarim Basin is a vast, arid depression in western China enclosed by massive mountain systems, including the Tien Shan, the Pamirs, and the Kunlun Mountains. Its extreme isolation and harsh climate, characterized by the Takla Makan Desert, have historically made it a distinct region separate from the central heartland, often maintaining its own oasis-based settlements and cultural identity.34