I envision the following as the most plausible borders of an industrial Chinese superpower:
- Qing borders WRT Mongolia, Manchuria, and Xinjiang. Tibet is optional depending on how recent the POD is; if the Mongols are Tibetan Buddhists then holding it is a must, otherwise it's pretty useless. This will be achieved in the proto-industrialization stage, as was the case IOTL, and seal the nomadic threat forever.
- Borders that bulge deeply into Mainland Southeast Asia. Depending on how early the POD is, it's possible that the entirety of the inland, including Upper Burma and northern Thailand, could be incorporated into the Chinese administrative system. People forget how empty almost the entirety of Southeast Asia was until the nineteenth century.
The Chinese Empire will not seek to expand overseas directly, as was always the case IOTL. Control over Mongolia, Manchuria, and Xinjiang are important for national security in the early phases of industrialization, and Mainland Southeast Asia will be brought under imperial administration
ex post facto after Chinese immigrants swamp the indigenous Burmese and Thai. Again, as was the case with the Hmong and Zhuang IOTL.
Then we have the
Kongsi States, which are empires run by Chinese corporations (
kongsi) in the fashion of the Honorable East India Company, the VOC, or the OTL
kongsi republics in Borneo. The following regions are especially ripe for
kongsi conquest:
- Most of Island Southeast Asia outside of Java, South Sulawesi, Aceh, and the few other places with sizable native populations. In an industrial China, it's almost a given that the majority population of OTL Indonesia will be Chinese.
- The Americas, which are too far away for the imperial authorities to curb the abuses of the Kongsi.
- Much of (commercially viable) Africa, which is again too far away for the authorities and lacking in centralized states.
- Siberia, for obvious reasons.
- Australia and Oceania, again for obvious reasons. However, some places like Hawai'i, Tahiti, and Tonga could survive due to a mix of both powerful monarchs who can readily be recognized by China and a lack of Chinese commercial interest.
Finally, a China-centered world order is likely to result in virtually the entire world recognizing the hegemony of whatever form the Chinese government may take, ultimately in return for protection from
kongsi aggression. Europe, the Islamic world, and India would be reduced to tributaries;
kongsi armies might be allowed to attack the more stubborn kings and sultans and rajas in order to acquire commercial privileges and force them to recognize Chinese domination.
Globally, the Chinese state itself pushes an image as a just adjudicator between
kongsi interests and indigenous demands. There is no concept of national sovereignty, all sovereignty being in China, and the world is a far more unipolar one.
Decolonization, if it ever happens, would take the form of the
kongsi corporations being dismantled or forced to give up paramilitary forces.