Actually when one nation is trying to use another nation air space for flights, generally permission needs to be taken from the respective governments.
China without taking Taiwan government permission, trying to enter into Taiwan air space.
China should understand one nation showing muscle power over other nation in 2021 is absolutely illegal.
Most of the global countries considering, such a provocative actions from the China is wrong and illegal and China should stop such things.
Even in 2021 also, like ancient years China is trying to enter into other area illegally.
In some countries it is trying to take ports on leases and even it is killing all small and medium scale manufacturing companies in those countries just to dump China products into those countries.
Whichever the countries leasing ports to China government, almost they are ending as poor nations. We can see practical examples like Pakistan, Sri Lanka etc whichever had given their motherland area for ports to China, ending as poor nations. Mainly manufacturing sector is getting destroyed by China post taking ports in such regions.
China is destroying World peace due to China interests in expansion beyond borders of China.