The related authorities of Taiwan and China finally came an agreement of Taiwan - China air routes. The aircrafts serving these routes, like Taipei - Shanghai routes operated by Far East Airlines and China Airlines of Taiwan, have to land at Hong Kong.

These makes the route much longer than the direct route, though this is faster than transit in Hong Kong.

Strangely, Okinawa, a Japanese Island 500km northeast of Taipei, is never considered as Taiwan - China air transport transfer hub, even it is much faster to transfer via Okinawa instead of Hong Kong / Macau for people travelling between places of China north of 30N latitude such as Shanghai, and Taiwan.

The authorities also never considered the Taipei - Shanghai routes stopping in Okinawa, so to cut travelling time from 4 hours to 3 hours.

Can anyone tell me why? Why no Japanese carriers make the geographical advantage of Okinawa, so to operate flights between Taiwan and China?

Thanks.