Why is South China Sea so highly contested?

China has voiced "strong dissatisfaction" after two US naval warships passed within 12 nautical miles of Chinese-claimed islands in South China Sea while conducting naval manoeuvring exercises, adding to simmering tensions in the strategic waterway.

China said it has dispatched warships to identify and warn off the US vessels. A statement on the Chinese defence ministry's website said the Arleigh Burke class guided-missile destroyer USS Higgins and Ticonderoga class guided-missile cruiser USS Antietam entered waters China claims in the Paracel island group "without the permission of the Chinese government."

It said the Chinese military ``immediately dispatched warships to identify and inspect the American ships according to law, and warned them to depart.''

The operation was conducted just over a week after Beijing flew nuclear-capable bombers to a disputed island in a bold power-play to show its military might and boost its territorial claims in the area.

The move prompted immediate criticism from the US, which last week pulled its invitation to China to join maritime exercises in the Pacific because of Beijing's "continued militarisation" of the South China Sea.



Beijing has been building artificial islands to reinforce its claim over most of the resource-rich South China Sea despite protests from Southeast Asian countries.

Here's why the South China Sea is so hotly contested. The sea covering 3.5 mn sq km borders Malaysia, Brunei, the Philippines, Vietnam, Taiwan and China and all have claims on the thousands of islands in the area.

The dispute has a lot to do with the natural resources – an estimated seven billion barrels of oil reserves in South China Sea and 900 to 1,000 trillion cubic ft reserve of gas,

Plus, the sea is a major global trade link - commodities from Africa and West Asia travel through South China Sea en route to China, Japan and South Korea.

Annual trade worth over $5 trillion happens on the route, 80% of Japanese, 40% of Chinese oil imports and 50% of India’s trade also pass through the area.

Its neighbours, particularly some of those involved in maritime disputes over the waters, have expressed fears China could eventually restrict freedom of navigation and overflight. It is for this reason smaller countries like Vietnam are looking to India to counter China.

China has controlled the Paracels entirely since violently seizing Vietnam's holdings in the area in 1974. Called "Xisha" in Chinese, the islands have been incorporated into the southern province of Hainan and are being developed for tourism, as well as being equipped with weapon systems meant to enforce China's claim to virtually the entire South China Sea.