The dispute has sparked diplomatic protests and contributed to a recent rise in tensions between Vietnam and China. It has led to confrontations between US and Chinese naval vessels, and may be behind Vietnam's decision in April to order six state-of-the-art diesel attack submarines from Russia, at a cost of 1.8 billion dollars.

And for many Vietnamese, China's claim to sovereignty over the entirety of what Vietnamese call the East Sea is a step too far.

"Vietnam is weaker (than China), but Vietnam has a long tradition of 'using weakness to defeat strength,'" said Do Tien Sam, director of Vietnam's Institute of Chinese Studies. "Vietnam does not provoke anyone, but if anyone provokes Vietnam, Vietnam will be ready for that."

The current flurry of diplomatic protests stems from a deadline imposed by treaty, which gave signatory nations until Wednesday to submit their claims to exclusive economic zones above their continental shelves. Such zones can extend up to 350 nautical miles (about 650 kilometres) from the shore.

Vietnam, Malaysia, the Philippines and Brunei all claim part or all of the Spratly and Paracel Islands and the South China Sea waters around them. The area is believed to contain substantial undersea oil reserves.

All four nations submitted their claims to UNCLOS, the UN body that administers the treaty, last week. Taiwan, which also claims the islands, cannot submit a claim because it is not a signatory state.

China quickly rejected Vietnam's and Malaysia's claims, which overlap the most with China's.

On Tuesday, Chinese Foreign Ministry spokesman Ma Zhaoxu said China has "indisputable sovereignty over the South China islands." He called Vietnam's submission to UNCLOS "illegal and invalid."

China submitted its own claims to UNCLOS, but a Vietnamese government source, speaking on condition of anonymity, told the German Press Agency

Deutsche Presse Agentur - May 13, 2009