Tensions are growing between the United States and China after Washington weighed in on territorial disputes between China and Southeast Asian nations in the South China Sea.
China lays claim to maritime territories in the sea along with Brunei, Malaysia, the Philippines, Taiwan and Vietnam. While most of the territory consists of small islands, boulders, and strips of sand, some of them are believed to be rich in oil and gas.
China, and the other disputing nations, have been developing tourism to some islands in order to justify their territorial claims.
Relations between China and the United States hit a rough patch after Washington offered to help resolve the decades-long dispute. Beijing described Secretary of State Hillary Clinton's suggestion to use collaborative diplomacy to resolve the thorny issue as interference and fear-mongering.
Clinton, in Hanoi for regional security meetings, said the U.S. was willing to help facilitate multilateral dialogue on the disputes. She said they should be resolved without coercion, threats, or the use of force.
"The United States, like every nation, has a national interest in freedom of navigation, open access to Asia' maritime commons and respect for international law in the South China Sea," said Clinton.
China's Foreign Minister, Yang Jiechi, this week condemned her remarks as an attempt to internationalize disputes that China wants addressed bilaterally.
He issued a statement saying the comments were an attack on China designed to give the international community what he called "a wrong impression" that the situation in the South China Sea is a cause for grave concern.
The fiery words built on tensions over U.S.-South Korean military exercises in the Sea of Japan and Washington's arms sales to Taiwan, which led Beijing to suspend military exchanges with the U.S. Beijing says Taiwan is Chinese territory that must one day be reunited with the mainland, by force if necessary.
Last year, Chinese ships harassed a U.S. navy vessel in international waters off the southern Chinese island of Hainan. China claims the ship was in its territory without permission. Also last year, a Chinese submarine, apparently following a U.S. navy ship, collided with a sonar array it was towing near the Philippines.
In March, China declared the South China Sea a "core interest" of its sovereignty, raising concerns in Southeast Asia.
Carl Thayer, professor of politics at Australia's University of New South Wales, points out that tensions have been growing in the region, especially between China and Vietnam.
"China has been declaring unilateral fishing bans over the last two years, chasing out Vietnamese boats, seizing their catches, fining them, holding fishermen hostage until fines are paid, seizing equipment and catches, declaring administrative control over islands," said Thayer. "It's done a whole series of activities that violate the letter and spirit of the declaration of conduct which encourages parties not to undertake unilateral actions, including naval maneuvers in the region."
Thayer also said China's naval build-up on Hainan and aggressive defense of its territorial claims is also raising concerns that Beijing intends to project its growing power. In response, he said, some nations are building up their own defensive capabilities.
"It's caused Southeast Asian states, Singapore, which had submarines to acquire new, more modern ones; Malaysia to acquire the Scorpene Submarines when it had none; Indonesia, which has postponed for financial reasons, to say it wants them; Australia's White Paper last year arguing for twelve more conventional submarine; and remarkably, Vietnam's contract to sign on for six kilo-class submarines, which are the most modern, conventional ones," Thayer said.
Washington's involvement in the South China Sea dispute was welcomed by Vietnam, which fought navy battles with China in the mid 1970s and late 1980s over the Paracel and Spratly island chains.
China in 2002 signed a declaration of conduct in the South China Sea with the 10 members of the Association of Southeast Asian Nations, agreeing to resolve the disputes peacefully.
ASEAN Secretary General Surin Pitsuwan last week said keeping the South China Sea's important shipping lanes open, safe, and secure is in the best interest for all parties. He said more than 85 percent of energy resources shipped to China, Japan, and South Korea come from or through Southeast Asia via the South China Sea.
"Because, it is really a lifeline of our commerce of our transport, for all of us. China, Japan, Korea, and Southeast Asia, and the countries beyond to the west," he said.
The territorial disputes have not interfered with trade but commercial interests have been affected. U.S. officials say China has been pressuring western oil companies not to work with Vietnam in disputed areas, threatening that their business interests in China could suffer.
Carl Thayer of Australia's University of New South Wales thinks U.S. involvement will balance China's power in the South China Sea and help ensure that international law remains the focus of resolving disputes rather than historical claims.