Probably expansion policy. I know China has this expansion policy.
Contrary to your imagination. In fact, China is facing an aging population and a sharp decline in population growth. Many cities in China are facing negative population growth, so the Chinese are not interested in expansion policies. But Taiwan is an exception, I can explain it to you.
This is how China deals with territorial issues:
1. The ruling legitimacy of PRC comes from the foundation and development of Sun Yat Sen's three people's principles, while Sun Yat Sen's ruling legitimacy comes from the abdication and grant of the emperor of the Qing Dynasty. Therefore, the PRC's territory came from the inheritance of the territory of the Qing Dynasty. Therefore, we declare ownership according to the map of the Qing Dynasty.
2. If a certain territory is the territory of the Qing Dynasty, the PRC has the right of inheritance. However, the PRC will not necessarily require the rule of this territory. We will operate according to its actual situation.
3. If this is the territory of Han people, such as Taiwan. Then there will be no room for compromise. According to the Han tradition, the territory of the Han people must be unified, and the Han people can only have a legitimate government. Any country can choose to recognize the Beijing government or the Taipei government, but it is not allowed to recognize both governments at the same time. Han people can accept the rule of Beijing government or Taipei government, but if there are two governments at the same time, the war will not stop. This is the fundamental reason why all previous dynasties of China have moved from division to reunification.
PRC is only a dynasty in the history of Chinese civilization. One day, the CCP regime will perish, just like the previous dynasties. Therefore, CCP has no right to abandon the unification tradition of the Han nationality.
It cannot be a precedent for undermining a civilization tradition of thousands of years. If the CCP dares to do so, it will no longer be the legal regime of the Han people.
4. If it is a minority territory, the PRC will consider the support of the local people. If the local people support the PRC, the PRC will establish autonomous regions to rule and give autonomy to laws and taxes (for example, Tibet, Xinjiang). If the local people do not support the PRC, the PRC will make them independent or join the country they like (for example, Mongolia, Badakhshan province of Afghanistan, gorno autonomous region of Tajikistan).
PS: different from the illusion of most Indians, most Tibetan people support the PRC because the PRC gives all Tibetan serfs freedom. Only a few serf owners fled to India. In Tibet, where the environment is bad, the PRC cannot rule without the support of the people.
About Southern Tibet, just like I said, if the local people support the PRC, we will establish the southern Tibet Autonomous Region. If not, we support their independence.
Aksai Chin is a no man's land. Ladakh is a disputed territory between China and Pakistan, not India. After India leaves, China is willing to negotiate with Pakistan to solve the Ladakh issue.
In fact, China only attaches importance to Ladakh, which is related to CEPC security, and southern Tibet is a bargaining chip that can be negotiated.
Do you know why China is so open to minority territories? Because China's historical experience tells us that it is a foolish act to forcibly rule the territory of ethnic minorities without the support of local people. That rule will eventually end because of endless guerrilla warfare.
If China forcibly occupies Indian territory, we will also face such a problem. So you think India's territory is gold, but we think it's a huge burden.