What strategic role does The South China Sea play to China?

In a nutshell,

1. $5 trillion worth of trade moves through the South China Sea each year.
2. Major Asian economies like China, Taiwan, Japan, and South Korea get their energy supplies from the Middle-East through this route

Due to the expansive nature of China’s military clout in the region based on its so-called “nine-dash line”, it has gained a special emphasis in U.S. foreign policy slip in recent years due to an increasing number of maritime territorial disputes that involves the ASEAN countries, making it a bigwig of regional tension.

(Source: Graphic News)

“Under international law, maritime claims in the South China Sea must be derived from land features. Any use of the ‘nine-dash line’ by China to claim maritime rights not based on claimed land features would be inconsistent with international law. The international community would welcome China to clarify or adjust its nine-dash line claim to bring it in accordance with the international law of the sea.”

Barack Obama, POTUS, said that “The Hague that declared illegal some of China’s artificial islands in the sea and invalidated its claims to almost the entire waterway…has helped clarify maritime rights”

China has denied foreign fishermen access to their traditional fishing grounds, for instance, Vietnamese fishing ships traveling through Vietnam’s Paracel Islands have been the victims of a Chinese vessel attack — waters China claims as its own in the South China Sea.

Chinese construction on the disputed Spratly Islands in the south China Sea. Beijing is reported to have now placed missiles on the nearby Paracel Island chain which it also claims as sovereign territory. Photograph: Armed Forces Of The Philippines/EPA

An appalling case in point is when China denied Filipino fishermen access to traditional grounds lying within the Philippines’ 370-kilometer (200-nautical-mile) exclusive economic zone. The Philippines had asked the Hague tribunal to declare China’s claims and actions invalid under the 1982 U.N. Convention on the Law of the Sea.

Fundamentally, dominating the South China Sea would:

1. Make it easier for China to defend its southern coastline — home to important economic centers, namely, Shanghai, Hong Kong.
2. Allow China to more easily to blockade Southeast Asian neighbours, especially Taiwan, Japan, and even South Korea, in case a crisis ever breaks out
3. Give China a safe stockade in which its ballistic missile submarines could operate & patrol in the South China sea without having to worry about US military assets tracking their every move, it enhances nuclear deterrence vis-à-vis the United States.

Put simply, it’s challenging the freedom of commerce & navigation that all countries in the region, including China, have profited from for decades.