The tug of war over the South China Sea is seen mainly as a struggle among rival claimants —China, Taiwan and several Southeast Asian states — for control of valuable fisheries as well as seabed oil, natural gas and mineral resources.
China's claim to about 80 percent of the 3.5 million square kilometer sea and its hundreds of atolls, rocks and reefs, has also alarmed outside seafaring and trading nations, including the United States and Japan. They regard the South China Sea as an international maritime highway with free navigation for seaborne trade, unimpeded movement of naval vessels, and unfettered over-flight for military aircraft.
But recent developments in China's nuclear weapons program suggest that there is another important dimension to Beijing's increasing assertiveness in enforcing its claimed jurisdiction in the semi-enclosed sea: protecting a new generation of nuclear-powered submarines armed with atomic warheads and based at Sanya on China's Hainan Island. "Without understanding the nuclear dimension of the South China Sea disputes, China's maritime expansion makes little sense," says Tetsuo Kotani, a special research fellow at the Okazaki Institute in Tokyo.