Dispute Between Vietnam and China Escalates Over Competing Claims in South China Sea

BEIJING — Vietnam said on Friday that it would conduct live-fire naval exercises off its coast next week, a step that escalated a long-running dispute with China over territory in the South China Sea that both nations claim.

The naval maneuvers follow an exchange of sharp statements on Thursday. Vietnam claimed that China had harassed a seismic survey boat, damaging a research cable trailing behind it, and China demanded that Vietnam halt oil-exploration activities in the area.

In an announcement on its Web site, Vietnam’s state-run Northern Maritime Safety Corporation said that nine hours of naval exercises would be held on Monday off the country’s central coast, and it warned other vessels to avoid the area. This is the first time that the government has publicized a live-ammunition drill, The Associated Press reported.

The diplomatic flare-up is the most serious confrontation this year in a territorial dispute that also involves the Philippines, Malaysia and Taiwan. All five countries have competing claims to parts of the South China Sea bed, which may hold valuable oil and mineral deposits. Arguments over the territory have continued for years, and the nations signed a 2002 accord that committed them to show restraint in disputed waters.

The issue heated up again last year because of a United Nations treaty that required all nations to file formal claims to continental shelf seabeds by the end of 2009. The documents that Vietnam and China filed asserted their competing territorial claims in the South China Sea more aggressively than they had before. China has seized scores of Vietnamese fishing boats in recent years, and Vietnam has responded with naval activities like the seismic survey this week.

China blames Hanoi for that episode, saying that armed Vietnamese boats were illegally chasing Chinese fishing boats out of the area, and that a fishing net accidentally snagged the research cable. Vietnam, however, called the damage to the research cable premeditated and said it was the second such confrontation in recent weeks.

The episode, Vietnam said, took place within the exclusive economic zone, extending 200 nautical miles from the Vietnamese coast, that is reserved for Hanoi under international law. China said it took place outside that zone.

Both countries are seeking to establish a demonstrated presence in the area, a principal requirement for pressing a territorial claim should negotiations over the maritime boundaries ever become serious.

One reason the dispute has flared in recent years is that the 2002 accord has proved to be toothless, Michael Vatikiotis, a security expert at the Center for Humanitarian Dialogue in Singapore, said in a telephone interview.

China’s neighbors have grown increasingly uncomfortable as the People’s Liberation Army Navy has opened a submarine base on Hainan Island, and has ranged across the South China Sea.

“It would appear that incidents involving China and other claimants have increased,” Mark Valencia, a maritime analyst in Hawaii and a leading expert on the dispute, said in an e-mail interview. “But why now — that’s the $64,000 question.”

With regard to China, he said, the answer is “perhaps, in part, because they can.”

This article has been revised to reflect the following correction:

Correction: June 11, 2011

An earlier version of this article misstated the basis for the Chinese position in a dispute over damage to a Vietnamese seismic survey boat's research cable. China said that the Vietnamese boat was outside the exclusive economic zone reserved for Vietnam under international law, not that the boat was within an overlapping zone of the same type claimed by China.