Strange airlines that only operate flights to Taiwan

Japan Airlines' subsidiary 'Japan Asia Airlines'
Air France's subsidiary 'Air France Asia'
British Airways' subsidiary 'British Asia Airways', etc...
These are Taiwan-specialized airlines established due to relations with China.
After Japan and China established diplomatic relations, a direct Beijing-Tokyo route was newly created in 1973,
but the Chinese side requested, "Airlines operating on Chinese routes are prohibited from operating in Taiwan,"
and the Japanese government abolished all of Japan Airlines' routes to Taiwan.
However, since the demand for Taiwan flights was also important,
they created a subsidiary under Japan Airlines dedicated solely to Taiwan flights.
Furthermore, they separated the airports, using Narita for China and Haneda for Taiwan.
At that time, Japan faced aviation sanctions from Taiwan for about a year.
Japan's diplomatic prowess in successfully establishing ties with China while managing to appease Taiwan
has become a textbook example of pragmatic diplomacy, used by countries worldwide
to establish diplomatic relations with China while maintaining ties with Taiwan.
As China transformed into a global power through reform and opening-up,
many countries around the world created Taiwan-specific subsidiaries, just like Japan did.

Countries around the world took issue with the Taiwanese flag on the Taiwanese national carrier, China Airlines,
and eventually, just before the handover of Hong Kong, they removed the flag from the aircraft and replaced it with a plum blossom.
However, since the 2000s, China has lifted the ban on foreign airlines operating in Taiwan.
Now, dozens of flights travel back and forth between China and Taiwan.
Following that trend, all of those subsidiaries, except for KLM Asia,
have been absorbed and merged into their parent companies.