One nation state
According to the international law, a nation has the right of “national self- determination.”
“National self- determination” means that a nation has the right to establish “one nation state.”
Therefore, if Taiwanese are one nation, they have the right to establish “one nation state.”
Then what is nation? Human beings can be classified by physical appearance.
That is race. Race is determined by genes. Race is science.
But science cannot determine nation. Nation is created by history and culture, not by genes.
National consciousness is created by the sense of common blood, common homeland, common language, common religion and etc.
It is said that “all members of a nation believe that they have the common destiny.”
The essence of nation is emotion. Nation is not science.
As Chinese Communist Party says, science can prove that Chinese and Taiwanese are the same race. But the point is not whether Chinese and Taiwanese are the same race or not. The point is whether Chinese and Taiwanese are the same nation or not. According to the recent public opinion poll in Taiwan, over 70% of the people who are now living in Taiwan answered the questionnaire that they were Taiwanese not Chinese, and only 2% of the people answered that they were Chinese not Taiwanese.
Chinese and Taiwanese are the same race. But consciousness, not science determines the nation. As long as Taiwanese insist that they are not Chinese, then they are not Chinese as a nation.
Considering these conditions, Taiwanese have the legitimate right to have an independent state, which is not China.
Non-intervention in internal affairs
On the other hand, legitimate central government has the right to exclusively control its people and territory. In these countries, separatist movements are considered to be serious crime against unity of the state. And the central government has legal right to suppress these crimes by employing military forces.
If separatist movement occurs within one nation, central government can suppress the movement by insisting that separatist movement is destroying the international principle of “one nation state.” Therefore, if Chinese and Taiwanese are one nation, Chinese invasion to Taiwan can be justified in international law.
And China can block foreign countries intervention by the international rule of “non-ntervention in internal affairs.”
But if Chinese and Taiwanese are different nations, Chinese invasion to Taiwan becomes “aggression to other independent country,” which is clearly violation of international law. And China has to prepare for the wide international sanctions by the international community.
Therefore, “One China Principle” is vitally important for the Chinese Communist Party to occupy Taiwan legally in international law and avoid military and economic pressure from international community. The theory of defending the nation's unity can give chances to China to avoid intervention from foreign countries in Chinese military operation to occupy Taiwan.
Military imbalance in the Western Pacific Ocean
Military balance in the Western Pacific Ocean tells us that the U.S. military forces are overwhelming Chinese military forces in the area surrounding Taiwan.
If the U.S. is an enemy of China, China has no chance to win the war in east Asia.
Therefore, if China wants to occupy Taiwan, it is absolutely necessary for China to avoid the intervention from the U.S. Considering these conditions, China has no option but to occupy Taiwan by diplomatic negotiations.
Diplomatic negotiation means “give and take” or 50/50 principle.
In diplomatic negotiation with the U.S., China has to give something to the U.S. instead of taking Taiwan. Is there anything that satisfies the U.S., even if the U.S. loses Taiwan? Considering the U.S. strategy “Make America Great Again”, it is very difficult for China to find something which satisfies the U.S.
Without guarantee of the U.S. non-intervention, it is very dangerous for China to attack Taiwan. If the U.S. military forces intervene in the Chinese military operation in Taiwan, it is very likely that Chinese military operation will fail.
If Chinese military operation fails, it will shake the Chinese Communist Party rule in China because Chinese military forces is the most important pillar to support the CCP dictatorship regime. If that pillar is damaged, CCP will lose the reliable tool to oppress the dissatisfied people in mainland China.
That might lead to the collapse of the CCP rule in China. Without guarantee of the U.S. non-intervention, taking Taiwan by military means is too dangerous and too risky for CCP dictatorship in China.
China’s reasonable strategy
If Chinese military operations are limited to take small islands very near to the Chinese coast, then the cost and risk of military operation becomes very low.
Small islands (180 square kilometers), Jinmen and Mazu are originally a part of Fujian province. Losing Chinese islands will not damage the legitimacy of independent-minded Taiwan government.
Therefore, Taiwan government will not fight to the death to defend these small islands.
The Chinese military forces will not meet the desperately fighting Taiwan military forces in these islands. And losing these small islands does not affect the U.S. world strategy.
Furthermore, president Mao failed to take these islands in 1950’s. Therefore, if president Xi succeeds to take these islands, he can say that he has exceeded president Mao’s achievement. Taking these small islands will give big political benefit to president Xi.
Conclusion
Top priority of all governments in the world is to remain in power. Therefore, reasonable policy for all governments is to take lower cost policy rather than high return policy. Considering present international relations, and U.S.-
China military balance in East Asia, taking all Taiwan island might bring big damage to the Chinese military forces.
For the survival of the CCP regime, taking small islands near the Chinese coast is more reasonable strategy for the Chinese Communist Party.