Why are flights from Fuzhou or Xiamen to Taiwan not allowed to overfly Taiwan strait? The flights from Kinmen or Matsu to Taiwan always overfly Taiwan strait. Why can't the flights from Xiamen or Fuzhou use the same route, fly over Kinmen or Matsu first and then to Taiwan directly, but need to fly away from the strait?
The answer to this question is covered in good detail in this news article in The Straits Times. Essentially, it's a political dispute between the countries of China and Taiwan.