South China Sea
The South China Sea is in ASEAN roughly from Singapore up to the Strait of Taiwan with around 3,500,000 square kilometers.
It has a strategic importance since almost half of the world's international shipping with container ships through these waters.
That is an important trade route for China since they carry their merchandise through here since about two thousand years. Actually, the present ownership claims of this water body of the red emperors in Beijing is ridiculous since there are more countries around it appears as if the communists want to ride on a nationalist tsunami so they resurrect the Emperors ideology of medieval ages.